Bihar Board 12th Maths Model Question Paper 3 in English Medium

Bihar Board 12th Maths Model Papers

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Time : 3 Hours 15 Min
Full Marks: 100

Instructions for the candidates :

  1. Candidates are required to give their answers in their own words as far as practicable.
  2. Figure in the right-hand margin indicates full marks.
  3. While answering the questions, the candidate should adhere to the word limit as far as practicable.
  4. 15 Minutes of extra time has been allotted for the candidate to read the questions carefully.
  5. This question paper is divided into two sections. Section-A and Section-B
  6. In Section A, there are 1-50 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with blue/black ball pen against the correct option on the OMR Sheet provided to you. Do not use Whitener/Liquid/ Blade/Nail on OMR Sheet otherwise result will be invalid.
  7. In section-B, there are 25 short answer type questions (each carrying 2 marks), out of which only 15 (fifteen) questions are to be answered.
    A part from this there is 08 Long Answer Type questions (each carrying 5 marks), out of which 4 questions are to be answered.
  8. Use of any electronic device is prohibited.

Objective Type Questions

There are 1 to 50 objective type questions with 4 options, choose the correct option which is to be answered on OMR Sheet. (50 × 1 = 50)

Question 1.
Let R be the relation in the set N given by R = {(a, b): a = b – 2, b > 6}. Which of the following is correct answer.
(a) (2,4) ∈ R
(b) (3,8) ∈ R
(c) (6,8) ∈ R
(d) (8,7) ∈ R
Answer:
(c) (6,8) ∈ R

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 2.
Let f: R → R be defined as f(x) = x4. Choose the correct answer ?
(a) f is one-one and onto
(b) f is many one onto
(c) f is one-one but not onto
(d) f is neither one-one nor opnto
Answer:
(d) f is neither one-one nor opnto

Question 3.
Let a binary operation on N defined as L.C.M. of a * b = a and b. Then (20 * 16) – (16 * 20) is equal to
(a) 4
(b) 60
(c) 0
(d) 1
Answer:
(c) 0

Question 4.
The value of \(\sin \left(\frac{\pi}{3}-\sin ^{-1}\left(-\frac{1}{2}\right)\right)\) is
(a) \(\frac{1}{2}\)
(b) \(\frac{1}{3}\)
(c) \(\frac{1}{4}\)
(d) 1
Answer:
(d) 1

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 5.
The principle value of \(\sin ^{-1}\left(\frac{\sqrt{3}}{2}\right)\) is
(a) \(\frac{2 \pi}{3}\)
(b) \(\frac{\pi}{6}\)
(c) \(\frac{\pi}{4}\)
(d) \(\frac{\pi}{3}\)
Answer:
(d) \(\frac{\pi}{3}\)

Question 6.
tan-1 =
(a) cos-1x
(b) \(\frac{1}{\cot ^{-1} x}\)
(c) \(\cot ^{-1} \frac{1}{x} 0\)
(d) -cot-1x
Answer:
(b) \(\frac{1}{\cot ^{-1} x}\)

Question 7.
The number of all possible matrices of order 3 x 3 with each entry 0 or 1.
(a) 27
(b) 18
(c) 81
(d) 512
Answer:
(d) 512

Question 8.
If A = \(\left[\begin{array}{cc}
\alpha & \beta \\
\gamma & -\alpha
\end{array}\right]\) such that A2 = I,
(a) 1 + α2 + βγ = 0
(b) 1 – α2+ βγ = 0
(c) 1 – α2 – βγ = 0
(d) 1 + α2 – βγ = 0
Answer:
(c) 1 – α2 – βγ = 0

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 9.
The value of determinant \(\left|\begin{array}{lll}
\frac{1}{a} & 1 & b c \\
\frac{1}{b} & 1 & c a \\
\frac{1}{c} & 1 & a b
\end{array}\right|\) is
(a) 0
(b) abc
(c) 1/abc
(d) None of these
Answer:
(a) 0

Question 10.
The value of determinant is \(\left|\begin{array}{lll}
2 & 7 & 65 \\
3 & 8 & 75 \\
5 & 9 & 86
\end{array}\right|\) is
(a) 0
(b) 1
(c) 2
(d) 3
Answer:
(a) 0

Question 11.
\(\left|\begin{array}{lll}
1 & x & x^{2} \\
1 & y & y^{2} \\
1 & z & z^{2}
\end{array}\right|=\)
(a) (x – y) (y + z) (z + x)
(b) (x+y) (y – z) (z – x)
(c) (x – y)(y – z) (z + x)
(d) (x – y)(y – z) (z – x)
Answer:
(d) (x – y)(y – z) (z – x)

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 12.
If , \(\left[\begin{array}{cc}
2 x-y & 5 \\
3 & y
\end{array}\right]=\left[\begin{array}{cc}
6 & 5 \\
3 & -2
\end{array}\right]\) then x =
(a) 3
(b) 4
(c) 5
(d) 8
Answer:
(b) 4

Question 13.
If \(f(x)=\left\{\begin{array}{l}
x, \text { if } x \geq 0 \\
0, \text { if } x<0
\end{array}\right.\) then the function is
(a) Continuous
(b) Discontinuous
(c) well defined
(d) None of these
Answer:
(b) Discontinuous

Question 14.
In how many points the function f(x) = \(\frac{1}{\log |x|}\) is discontinuous
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(c) 3

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 15.
The differential of sin (x2 + 5) is
(a) 2 sin (x + 5)
(b) 2 cos (x2 + 5)
(c) 2x cos (x2 + 5)
(d) None of these
Answer:
(c) 2x cos (x2 + 5)

Question 16.
If y = log x then the value of \(\frac{d y}{d x}\) is
(a) x log x
(b) \(\frac{1}{x \log x}\)
(c) \(\frac{1}{\log x}\)
(d) \(\frac{1}{ x }\)
Answer:
(d) \(\frac{1}{ x }\)

Question 17.
If y = (3x2 – 9x + 5)9 then \(\frac{d y}{d x}\) is equal to :
(a) 27 (3x2 – 9x + 5)8 (2x – 3)
(b) 27 (3x2 – 9x + 5)
(c) 27 (2x – 3)
(d) None of these
Answer:
(a) 27 (3x2 – 9x + 5)8 (2x – 3)

Question 18.
The rate of change the area of circle w.r.t.r, when r = 5 cm.
(a) 10πcm2/cm
(b) 12πcm2/cm
(c) 8π cm2/cm
(d) 11πcm2/cm
Answer:
(a) 10πcm2/cm

Question 19.
The function f(x) = sin x is strictly increasing in the interval
(a) (0,1)
(b) \(\left(\frac{\pi}{2}, \pi\right)\)
(c) \(\left(0, \frac{\pi}{2}\right)\)
(d) None of these
Answer:|
(c) \(\left(0, \frac{\pi}{2}\right)\)

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 20.
The function f(x) = e2x is
(a) strictly increasing
(b) strictly decreasing
(c) neither incrasing nor decreasing
(d) None of these
Answer:
(a) strictly increasing

Question 21.
The slope of tangent to the curve y = x2 + 3r + 4 at (1,1) is
(a) 5
(b) \(-\frac{1}{5}\)
(c) 8
(d) None of these
Answer:
(b) \(-\frac{1}{5}\)

Question 22.
The line y = mx is a tangent to the curve y2 = 4r if the value of m is
(a) 1
(b) 2
(c) 3
(d) \(\frac{1}{2}\)
Answer:
(a) 1

Question 23.
If f(x) = 3x2 + 15x + 5, then approximate value of f(3.02) is
(a) 47.66
(b) 57.66
(c) 67.66
(d) 77.66
Answer:
(d) 77.66

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 24.
The antiderivative of (ax + b)2 is
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 1
Answer:
\(\frac{1}{3 a}(a x+b)^{3}+C\)

Question 25.
\(\int \frac{\sin ^{2} x-\cos ^{2} x}{\sin ^{2} x \cos ^{2} x} d x\) is equal to
(a) tan x + cot x + C
(b) tan x + cosec x + C
(c) – tan x + cot x + C
(d) tan x + sec x + C
Answer:
(a) tan x + cot x + C

Question 26.
∫ log xdx is equal to
(a) xlogx + x + C
(b) xlogx – x + C
(c) log x + x + C
(d) logx – x + C
Answer:
(b) xlogx – x + C

Question 27.
If f(a + b – x) = f(x) then \(\int_{a}^{b} x f(x) d x\) is equal to
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 2
Answer:
\(\frac{a+b}{2} \int_{a}^{b} f(x) d x\)

Question 28.
The value of \(\int_{0}^{1} \tan ^{-1}\left(\frac{x}{1+x^{2}}\right) d x\) is
(a) 1
(b) \(\frac{\pi^{2}}{32}\)
(c) -1
(d) \(\frac{\pi}{4}\)
Answer:
(b) \(\frac{\pi^{2}}{32}\)

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 29.
\(\int_{0}^{1} \tan ^{-1}\left(1-x+x^{2}\right) d x\) is equal to
(a) log 2
(b) \(\log \frac{1}{2}\)
(c) πlog2
(d) \(\frac{\pi}{2} \log \frac{1}{2}\)
Answer:
(c) πlog2

Question 30.
The area enclosed by circle x2 + y2 = a2 is
(a) 4
(b) πa2
(c) 2
(d) 1
Answer:
(b) πa2

Question 31.
The order and degree of \(\left(\frac{\mathrm{ds}}{\mathrm{dt}}\right)^{4}+3 \mathrm{s} \frac{\mathrm{d}^{2} \mathrm{s}}{\mathrm{dt}^{2}}=0\) is
(a) 1, 2
(b) 2, 1
(c) 2, 4
(d) 4, 2
Answer:
(b) 2, 1

Question 32.
Which of the following is linear differential equation ?
(a) (4x + 6y + 5) dy – (3y + 2x + 4)dx = Q
(b) xydx – (x3 + y3) dy = 0
(c) (x3 + 2y2) dx + 2xydy = 0
(d) y2dx + (x2 – xy – y2) dy = 0
Answer:
(d) y2dx + (x2 – xy – y2) dy = 0

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 33.
The integrating factor at the diff eqn (1 – y2) \(\frac{d x}{d y}\) + yx = ay (-1 < y < -1) is
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 3
Answer:
(d) \(\frac{1}{\sqrt{1-y^{2}}}\)

Question 34.
The general solution of diff eq \(\frac{y d x-x d y}{y}=0\) is
(a) xy = C
(b) x = cy2
(c) y = cx
(d) y = cx2
Answre:
(c) y = cx

Question 35.
The generval solution of diff. eqn exdy + (yex + 2x)dx = 0 is
(a) xex + x2 = C
(b) xey + y2 = C
(c) yex + x2 = C
(d) yex + x2 = C
Answer:
(c) yex + x2 = C

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 36.
If the adjacent side of parallelogram are \(\vec{a}\) and \(\vec{b}\) then its area is
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 4
Answer:
(a) \(|\vec{a} \times \vec{b}|\)

Question 37.
If a + b + c = 0 then
(a) \(\vec{a} \cdot \vec{b}=0\)
(b) \(\vec{a}=\vec{b}\)
(c) \(\vec{a} \times \vec{b}=\vec{b} \times \vec{c}=\vec{c} \times \vec{a}\)
(d) None of these
Answer:
(c) \(\vec{a} \times \vec{b}=\vec{b} \times \vec{c}=\vec{c} \times \vec{a}\)

Question 38.
If \(\vec{a}\) and \(\vec{b}\) are two vectors then \((\vec{a}+\vec{b}) \cdot(\vec{a}-\vec{b})\) is equal to
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 5
Answer:
(d) \(2(a \times b)\)

Question 39.
The angle between the vectors 2î – 3ĵ + 2k̂ and î + 4ĵ + 5k̂ is
(a) 30°
(b) 90°
(c) 45°
(d) 60°
Answer:
(b) 90°

Question 40.
If θ be the angle between the vectors \(\vec{a}\) and \(\vec{b}\) then sin θ is
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 6
Answer:
(a) \(\frac{\vec{a} \cdot \vec{b}}{|\vec{a} \| \vec{b}|}\)

Question 41.
The mean and variance of a binomial distribution are 6 and 1 respectively. Then the value of parameter n is
(a) 18
(b) 12
(c) 10
(d) 9
Answer:
(a) 18

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 42.
The plane x = 0,y = 0 is
(a) Parattel
(b) Perpendicular
(c) Intersect z-axis
(d) None of these
Answer:
(c) Intersect z-axis

Question 43.
Linear programming problem is with
(a) One objective function
(b) Two objective function
(c) No objective function
(d) None of these
Answer:
(a) One objective function

Question 44.
If P(A) = 0.8, P(B) = 0.5 and P(B/A) = 0.4 then P(A/B) =
(a) 0.32
(b) 0.64
(c) 0.16
(d) 0.25
Answer:
(b) 0.64

Question 45.
The mean and variance of a random X are 4 and 2 respectively P(X = 1) is
(a) 1/32
(b) 1/16
(c) 1/8
(d) 1/4
Answer:
(b) 1/16

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 46.
The pair of dice are rolled. The probability of obtaining an even prime number on each die is
(a) 1/36
(b) 1/12
(c) 1/6
(d) 0
Answer:
(a) 1/36

Question 47.
If P(A∪B) = 0.8 and P(A∩B) = 0.3 then P(Ā) + P(B̄) =
(a) 0.3
(b) 0.5
(c) 0.7
(d) 0.9
Answer:
(a) 0.3

Question 48.
Let the binary operation * on R defined by x *y = 1 + 12x + xy ∀ x,y ∈ R then 2 * 3 is
(a) 31
(b) 41
(c) 43
(d) 51
Answer:
(a) 31

Question 49.
Which of the following is the equation of ary – plane
(a) x = 0
(b) y = 0
(c) x = k
(d) z = 0
Answer:
(a) x = 0

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 50.
In a hostel 60 % of the students read Hindi news paper, 40% read. English news paper and 20% read both Hindi and English news paper. Then what is probability that reads neither Hindi nor English news paper
(a) 0.2
(b) 0.3
(c) 0.4
(d) 0.5
Answer:
(a) 0.2

Non – Objective Type Questions

Short Answer Type Questions

Q. No. 1 to 25 are of Short Answer type carry of 2 marks each. Answer any 15 questions. (15 × 2 = 30)

Question 1.
Let N be the set of natural numbers and relation R define one N. as R = {(x,y); x,y ∈ N and x divide y} Verify that the whether R is reflexive, symmetric and transitive.
Answer:
Let.x, y, z, ∈ N
(i) xR.x ⇒ x divide x i.e. xRx. ∀ x ∈ N. So R is reflexive.
(ii) x divide y ⇒ xRy ⇒ (x, y) ∈ R but (y, x) ∉ R. Since .x divide y therefore it is not possible y divide x due to x, y ∈ N.SoR is not symmetric
(iii) x divide y, y divide z ⇒ x divide z i.e. .xRy, yRz ⇒ yRz So R is transitive.

Question 2.
Show that the function f: N → N defined as f(x) = 2x is one-one but not onto.
Answer:
we have f(x) = 2x ⇒ f(x1) = f(x2) ⇒ 2x1 = 2x2
⇒ x1 = x2 so, f is one-one
Further,f is not onto, as for 1 ∈ N, there does not exist any x in N such that f(x) = 2x = 1 ∈ N.
Thus f is one-one but not onto

Question 3.
Prove that the binary opeation * on the set N such that a * b = \(\frac{a+b}{2}\) ∀ a,b,∈ N is commutative but not associative.
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 7
Thus the binary operation * is commutative but not associative

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 4.
Find the value of cot [tan-1 a + cot-1 a]
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 8

Question 5.
Prove that \(\sin ^{-1} \frac{2 \sqrt{2}}{3}+\sin ^{-1} \frac{1}{3}=\frac{\pi}{2}\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 9

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 6.
Find the value of x if \(\left[\begin{array}{ll}
x & 4 \\
2 & 2 x
\end{array}\right]=0\)
Answer:
\(\left[\begin{array}{ll}
x & 4 \\
2 & 2 x
\end{array}\right]=0\)
⇒ 2x2 = 8 ⇒ x2 = 4 ⇒ x = ±2

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 7.
If A = \(\left[\begin{array}{lll}
3 & \sqrt{3} & 2 \\
4 & 2 & 0
\end{array}\right]\) then prove that (A’)’ = A
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 10

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 8.
Find the value at x if \(\left|\begin{array}{ll}
3 & x \\
x & 1
\end{array}\right|=\left|\begin{array}{ll}
3 & 2 \\
4 & 1
\end{array}\right|\)
Answer:
\(\left|\begin{array}{ll}
3 & x \\
x & 1
\end{array}\right|=\left|\begin{array}{ll}
3 & 2 \\
4 & 1
\end{array}\right|\)
Answer:
⇒ 3 – 2x2 = 3- 8 ⇒ x2 = 8
∴ x = ±2√2

Question 9.
Find the value of x and y if \(\left|\begin{array}{ll}
2 & 3 \\
y & x
\end{array}\right|=4\) and \(\left|\begin{array}{ll}
x & y \\
2 & 1
\end{array}\right|=\frac{7}{2}\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 11
⇒ y = -3
Multiplying (2) by 2 and subtract (1), we get Putting the value of y in (2), we get
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 12

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 10.
If a matrix has 24 elements. What are the possible orders it can have ? what, if has 13 element.
Answer:
The possible order of matrices for 24 elements are :
1 × 24, 24 × 1,2 × 12, 12 × 2, 3 × 8,8 × 3, 4 x 6 and 6 × 4
Again, possible order of matrices for 13 elements are 1 × 13 and 13 × 1.

Question 11.
Verify the Rolle’s theorem of the function f(x) = x3 (x – 1)2 for the interval [0,1)
Answer:
Given, f(x) = 3(x – 1)2
⇒ f'(x) = 3x2 (x-1)2 + x3 2(x – 1) = x2 (x – 1) (3 (x – 1) + 2x) or, f'(x) = x2 (x – 1) (5x – 3)
clearly f(x) is differentiable and continuous for each x.
(ii) f(x) is differentiable in (0, 1)
(iii) f(0) = 0 and f(1) = 0, ∴ f(0) =f(1)
So, all the condition of the Rolles theorem are satisfies for the function f(x) in (0, 1). Then f'(c) = 0
⇒ c2(c – 1)(5c – 3) = 0 c = 0,1,3/5
But 0< c < 1 ∴ c = 3/5

Question 12.
If x = at2, y = 2at. then find that dy/dx
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 13

Question 13.
Find the anti derivative F off defined by f(x) = 4x3 – 6, where F(0) = 3.
Answer:
one anti-derivative of f(x) is x4 – 6x since
\(\frac{d}{d x}\) (x4-6x) = 4x3 – 6
Therefore, the anti derivative F is given by
F(x) = x4 – 6x + C, where C is constant
Given that F(0) = 3, which gives 3 = 0 – 6 × 0 + C
⇒ C = 3
Thus, the required anti-derivative is the unique function F defined by F(x) = x4 – 6x + 3

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 14.
Evaluate: \(\int_{0}^{1} x(1-x)^{23} d x\)
Answer:
Let z = 1 – x, then dz = -dx and x = 1 – z
when x = 0, z = 1 and when x = 1, z = 0
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 14

Question 15.
Evaluate: \(\int_{a}^{b} \frac{\log x}{x} d x\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 15

Question 16.
Find the differential equation of the curve y = Aex + Be-x; where A and B are constant.
Answer:
y = Aex + Be-x
Differentiating both side w.r.t. x, we get
\(\frac{d y}{d x}\) = Aex + Be-x
Again, differentiating w.r.t we get
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 16
or, \(\frac{d^{2} y}{d x^{2}}-y=0\) which is required, differential equation.

Question 17.
Find the particular solution of the differential equation \(\frac{d y}{d x}\) = ytanx when y = 1 if x = 0
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 17
⇒ logy = -logcos x+ logC
⇒ log y + logcosx = log C
⇒ log (ycosx) = logC ⇒ ycosx = C …….(1)
Now, putting y= I and x = 0 in (1), we get
cos 0 = C ⇒ C = 1 ∴ y cos x = 1
y = \(\frac{1}{\cos x}\) ⇒ y = sec x

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 18.
Find the unit vector in the direction of the vector \(\overrightarrow{\mathrm{a}}=2 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}+\hat{\mathrm{k}}\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 18
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 19

Question 19.
If \(\overrightarrow{\mathrm{a}}=2 \hat{\mathrm{i}}+\hat{\mathrm{j}}+3 \hat{\mathrm{k}}\) and \(\overrightarrow{\mathbf{b}}=3 \hat{\mathbf{i}}+5 \hat{\mathbf{j}}-2 \hat{\mathbf{k}}\) then find the \(|\overrightarrow{\mathrm{a}} \times \overrightarrow{\mathrm{b}}|\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 20

Question 20.
Find the equation of the planes parallel to the plane dr -3y + 2z + 9 = 0 and at distance 5 from the origin.
Answer:
Let the plane 6x – 3y + 2z + k = 0 is the parallel, to the plane 6x – 3y + 2z + 9 = 0. Now, the distance of plane 6x – 3y + 2z + 9 = 0 from the origin is
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 21
Thus the plane is 6x – 3y + 2k ± 35 = 0

Question 21.
A Player has 7 cards in hand of which 5 arc red and of these five 2 are kings. A card is drawn at random. Find the probability that it is a king, it is known that it is red.
Answer:
Let A = The event of red card and B = The event of king.
Then n(A) = 5 and the events are red and king is = A ∩ B
∴ n(A) = 5 and the events of red and king – A∩B
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 22

Question 22.
Find the probability of the occurrence of a number greater than 1 if it is known that only odd numbers can occur in a die.
Answer:
Let A = The event of occurrence odd number and B = the event of occurrence the odd number greater Then
Then A = {1, 3,5} ⇒ n(A) = 3 and B = {3,5)
then A ∩ B = {3,5} ⇒ n(A∩B) = 2
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 23

Question 23.
Verify the continuity of the function f(x) = 2x2 – 1 at x = 3.
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 24

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 24.
The radius of a circle is increasing at the rate of 0.7 cm/s. What is the rate of increase of its circumference when r = 4.9 cm ?
Answer:
Let c and r be the circumference and radius of circle. Then
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 25

Question 25.
Find the slope of the tangent to the curvey = x3 – x + 1 at the point whose x-co-ordinate is 2.
Answer:
Given the curve y = x3 – x + 1
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 26

Long Answer Type Questions

Questions No. 26 to 33 are Long Answer Type Questions. Each question carry 5 marks. Answer any 4 question. (4 × 5 = 20)

Question 26.
Prove that of all the rectangles inseribed in a given circle the square has the maximum area.
Answer:
Let ABCD be a rectangle inscribed in a given circle of centre O and radius r.
Let AB = 2x and BC = 2y,
∴∆ AOAM be a right angled triangle. Then
OA2 = AM2 + OM2
or, a2 = x2 + y2
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 27
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 28
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 29
Hence area is maximum when x = y
or, 2x = 2y Thus the rectangle is square.
Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 27.
Verify Lagrange’s mean value theorem when the function f(x) = (x – 1) (x – 2) (x – 3) in the interval [0,4].
Answer:
The given function, f(x) = (x – 1)(x – 2)(x – 3) in interval [0,4]
⇒ f(x) = (x2 -x -2x + 2) (x – 3)
⇒ f(x) = (x2 – 3x + 2) (x – 3) = x3 – 3x2 + 2x – 3x2 + 9x – 6
⇒ f(x) = x3 -6x2 + 11x – 6
Since f(x) is a polynomial function and polynomial function is continuous, i.e. f(x) is continuous in [0, 4]
Also, f'(x) = 3x2 – 2x +11, exists in interval ]0, 4[.
So, f(x) is differentiable in ]0,4[. Thus Lagrange’s theorem are satisfied
∴ c ∈] 0,4 [ exist.
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 30
Clearly, the both value of c lie between ] 0, 4 [. Thus theorem is verified.

Question 28.
Find area enclosed by the ellipse \(\frac{x^{2}}{9}+\frac{y^{2}}{4}=1\)
Answer:
We have, The equation of ellipse
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 31
Putting x = 3sinθ ⇒ dx = 3cosθ. Also,
when x = 0, then θ = 0 and when A = 3 then θ = π/2
∴ Required area of the ellipse
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 32
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 33

Question 29.
Evaluate: \(\int_{0}^{\pi / 2} \log \sin x d x\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 34
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 35

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 30.
Prove that
\(\overrightarrow{[a} \times \vec{b}, \vec{b} \times \vec{c}, \vec{c} \times \vec{a}]=[\vec{a}, \vec{b}, \vec{c}]^{2}\)
Answer:
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 36

Question 31.
Find the co-ordinates of the foot of the perpendicular drawn from the origin to the plane 2r – 3y + 4z – 6 = 0.
Answer:
Let the co-ordinates of the foot of the perpendicular P from the origin to the plane is P (x1, y1, z1).
Then the direction ratios of the line OP are x1y1, z1.
Now the direction ratio of the plane is 2, – 3, 4. So direction cosines are
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 37
Now, since the direction cosines and direction ratios of the line are proportional. Then
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 38
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 39
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 40
Thus the co-ordinates of foot of perpendicular is
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 41

Question 32.
Solve the LPP: Minimize Z = – 3x + 4x
under the constraints x + 2y ≤ 8, 3x + 2y ≤ 12, x ≥ 0, y ≥ 0.
Answer:
Minimize Z = -3x + 4. under the costraints
A + 2y ≤ 8 ⇒ x + 2y = 8 …..(1)
3x + 2y ≤ 12 ⇒ 3x + 2y = 12 …(2)
x ≥ 0, y ≥ 0 ⇒ x = 0, y = 0 …(3)
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 42
First of all draw the graph of the equations (1) to (3) corresponds to the inequations. It is clear from figure, that (1) and (2) are intersect each other at the point (2,3). So, we get a feasible region OABC, which is bounded. The co-ordinates of the corner points of the feasible region are 0(0, 0) A(4,0), B(2, 3) and C (0, 4). Lastly, applying corner point method to find the value of the objective function Z are as follows :
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 42(i)
It is clear from the above table that the minimum value of Z at the point (4,0) is – 12. Thus the minimum value of Z is -12

Bihar Board 12th Maths Model Question Paper 3 in English Medium

Question 33.
A furniture dealer deals in only two items tables and chairs. He has Rs. 5000/- to invest and a space to store at most 60 pices. A table costs him Rs. 250 and a chair Rs. 50. He can sell a table at a profit to Rs. 50 and a chair at a profit of Rs. 15. Assuming that he can sell all the items that he buys how should he invest his money in order that he may maximize his profit.
Answer:
Let x and y represents tables and chairs respectively. Now, by question costs of x tables = 250 x and the chair = 50y ∴ Total costs (250x + 50y)
Since the dealer has invest Rs. 5000
∴ 250x + 50v ≤ 5000 =>5y + y ≤ 100
Again, the dealer has a space to store at most 60, so
x + y ≤ 60
Also, non-negative constraints : x ≥ 0, y ≥ 0.
Further, profit from x table = 50.v and y chair = 15y
Objective Function Z = 50x + 15y
So. the mathematical form of the problem are as follows
Maximize Z = 50x + 15y
Subject to constraints 5x + y ≤ 100 ⇒ 5x + y = 100 .. .(1)
v + y ≤ 60 ⇒ x + y = 60 .. .(2)
x ≥ 0, y ≥ 0 ⇒  x = 0, y = 0 …(3)
First of all draw the graph of equations (1) to (3) corresponds to inequations. On joining the points (20, 0),
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 43
(0,100) and (60,0), (0,60) we get two straight line, which intersects at the point (10, 50). The point of intersection (10, 50) can be obtained from solving equations (1) and (2). It is clear from figure OABC be the feasible region, which is bounded. Lastly, by the using comer points of feasible region 0(0, 0), A(20,0), B(10,50) and C(0, 60) to find the maximum values of Z :
Bihar Board 12th Maths Model Question Paper 3 in English Medium - 44
It is clear from the table that the maximum value of Z is Rs. 1250. Thus the maximum profit to the dealer for buying 10 tables and 50 chairs.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Bihar Board 12th Chemistry Model Papers

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Time : 3 Hours 15 Min
Full Marks: 70

Instructions for the candidates

  1. Candidates are required to give answers in their own words as far as practicable.
  2. Figures in the right hand margin indicates full marks.
  3. While answering the questions, candidate should adhere to the words limit as far as practicable.
  4. 15 Minutes of extra time has been allotted for the candidates to read the questions carefully.
  5. This question paper is divided into two sections : Section -A and Section-B
  6. In Section A, there are 35 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with blue/black ball pen against the correct option on OMR Sheet provided to you. Do not use Whitener/Liquid/Blade/ Nail on OMR Sheet otherwise your result will be treated as invalid.
  7. In section-B, there are 18 short answer type questions (each carrying 2 marks), out of which only 10 (ten) questions are to be answered Apart from this there are 06 Long Answer type questions (each carrying 5 marks), out of which 3 questions are to be answered.
  8. Use of any electronic device is prohibited.

Objective Type Questions

In the following questions no. from 1 to 35, there is only one correct answer against each question. For each question, mark (darken) the correct answer on the OMR Sheet provided to you. (1 x 35 = 35)

Question 1.
Which among the following will show anisotropy ?
(a) Glass
(b) NaBr
(c) Plastic
(d) Rubber
Answer:
(b) NaBr

Question 2.
Study the figure of a solid given below depicting the arrangement of particles. Which is the most appropriate term used for the figure ?
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1
(a) Isotropy
(b) Anisotropy
(c) Irregular
(d) Amorphous nature
Answer:
(b) Anisotropy

Question 3.
Which of the following forms a molecular solid when solidified ?
(a) Calcium fluoride
(b) Silicon dioxide
(c) Carbon dioxide
(d) Sodium chloride
Answer:
(c) Carbon dioxide

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 4.
Ionic solids conduct electricity in molten state but not in solid state because ……………..
(a) in molten state free ions are furnished which are not free to move
(b) in solid state in solid state ionic are hard, brittle and become soft in molten state
(c) all solids conduct electricity in molten state
(d) in solid state ions are converted to atoms which are insulators.
Answer:
(a) in molten state free ions are furnished which are not free to move

Question 5.
The major binding force in diamond, silicon and quartz is ………………
(a) electrostatic force
(b) electrical attraction
(c) covalent bond force
(d) van der Waals force
Answer:
(c) covalent bond force

Question 6.
Homogeneous mixture of two or more than two components is called …………….
(a) solute
(b) solvent
(c) both (a) and (b)
(d) solution
Answer:
(d) solution

Question 7.
Which of the following is an example of gaseous solution ?
(a) Camphor is nitrogen gas
(b) Solution of hydrogen, in palladium
(c) Chloroform mixed with nitrogen gas .
(d) Both (a) and (c)
Answer:
(d) Both (a) and (c)

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 8.
In a Daniell cell,
(a) the chemical energy liberated during the redox reaction is converted to electrical energy
(b) the electrical energy of the cell is converted to chemical energy
(c) the energy of the cell is utilised in conduction of the redox reaction
(d) the potential energy of the cell is converted into electrical energy.
Answer:
(a) the chemical energy liberated during the redox reaction is converted to electrical energy

Question 9.
Which of the following is the correct cell representation for the given cell reaction ?
Zn H2SO4 → ZnSO4 + H2
(a) Zn|Zn2+||H+|H,
(b) Zn |Zn2+||H+, H,|Pt
(c) Zn |ZnSO4||H2SO4|Zn
(d) Zn|H2SO4||ZnSO4|H2
Answer:
(b) Zn |Zn2+||H+, H,|Pt

Question 10.
When a chemical reaction takes place, during the course of the reaction the rate of reaction
(a) keeps on increasing with time
(b) remains constant with time
(c) keeps on decreasing with time
(d) shows irregular trend with time
Answer:
(c) keeps on decreasing with time

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 11.
For a reaction P + Q → 2R + S. Which of the following statements is incorrect ?
(a) Rate of disappearance of P = Rate of appearance of S
(b) Rate of disappearance of Q = 2 x Rate_of appearance of R
(c) Rate of disappearance of P = Rate of disapearance of Q
(d) Rate of disappearance of Q= -1/2 x Rate of appearance of R
Answer:
(b) Rate of disappearance of Q = 2 x Rate_of appearance of R

Question 12.
After the reaction is over between adsorbed reactants, it is important to create space for the other reactant molecules to approach the surface and react. The process responsible for this is known as ………….
(a) sorption
(b) desorption
(c) physisorption
(d) chemisorption
Answer:
(b) desorption

Question 13.
Powdered substances are more effective adsorbents than their crystalline form because
(a) adsorption is an exothermic process
(b) they become inert and do not react with the adsorbate
(c) the extent of adsorption increases with increase in surface area of the adsorbent
(d) adsorption is more if the size of adsorbent is small
Answer:
(c) the extent of adsorption increases with increase in surface area of the adsorbent

Question 14.
Which of the following example is not correctly matched ?
(a) Two most abudant elements-Fe, AI
(b) Two metals which occur in native state-Au, Pt
(c) Two metals which can occur in combined and native state both-Zn,Fe.
(d) None of these
Answer:
(c) Two metals which can occur in combined and native state both-Zn,Fe.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 15.
Which of the following is not the correct name of the formula of the ore given with it ?
(a) MgSO4.7H2O – Epsom salt
(b) CuCO3.Cu(OH)2 – Malachite
(c) KAlSi3Og– Feldspar
(d) MgCl2.6H2O – Dolomite
Answer:
(d) MgCl2.6H2O – Dolomite

Question 16.
Nitrogen shows different oxidation states ranging from
(a) -3 to +5
(b) -5 to + 5
(c) 0 to -5
(d) -3 to +3
Answer:
(a) -3 to +5

Question 17.
The oxidation state of nitrogen is highest in ……………….
(a) N3H
(b) NH3
(c)NH2OH
(d) N2H4
Answer:
(a) N3H

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 18.
General electronic configuration of transition metals is ………………….
(a) (n-1)d1_10ns2
(b) ndwns2
(c) (n-1)d10ns2
(d) (n-1)d15ns2
Answer:
(a) (n-1)d1_10ns2

Question 19.
Which one of the following is a ‘d-block element’ ?
(a)Gd
(b)Hs
(c) Es
(d) Cs
Answer:
(b)Hs

Question 20.
Copper sulphate dissolves in ammonia due to the formation of
(a) Cu2O
(b) [Cu(NH3)4]SO4
(c) [Cu(NH3)4]OH
(d) [Cu(H2O)4]SO4
Answer:
(b) [Cu(NH3)4]SO4

Question 21.
The numberofions given by [Pt(NH3)6]Cl4 inaqueous solution wil be ………………….
(a) two
(b) three
(c) five
(d) eleven
Answer:
(c) five

Question 22.
Which of the following is a primary halide ?
(a) iso-Propyl iodide
(b) sec-Butyl iodide
(c) tert-Butyl bromide
(d) neo-Hexyl   chloride
Answer:
(d) neo-Hexyl   chloride

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 23.
Which of the following is not an allylic halide ?
(a) 4-Bromopent-2-ene
(b) 3-Bromo-2-methylbut-l-ene
(c) 1-Bromobut-2-ene
(d) 4-Bromobut-1-ene
Answer:
(d) 4-Bromobut-1-ene

Question 24.
C5H12O is a monohydric alcohol. How many isomers of this alcohol are possible ? How many of these contain chiral centres as well as can exhibit enantiomerism ?
(a) 8 and 3
(b) 6 and 2
(c) 4 and 2
(d) 12 and 4
Answer:
(a) 8 and 3

Question 25.
IUPAC name of
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.2
(a) 3-propylbutan-1-o1
(b) 2-ethylpentan-1-o1
(c) 3-methyl hydroxyhexane
(d) 2-ethyl-2-propyl ethanol
Answer:
(b) 2-ethylpentan-1-o1

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 26.
Which of the following structures is not correctly matched ?
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.3
Answer:
(c)

Question 27.
Which of the following carbonyl compounds is most , polar ?
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.4
Answer:
(d)

Question 28.
Nitrogen atom of amino group is……
(a) sp
(b)sp2
(c) sp3
(d) sp3d
Answer:
(c) sp3

Question 29.
C3H9N cannot represent
(a) 1° amine
(b) 2° amine
(c) 3° amine
(d) quaternary ammonium salt
Answer:
(d) quaternary ammonium salt

Question 30.
The general formula of carbohydrates is……………….
(a) CnH2n+10
(b) CnH2nO
(c) Cn(H2O)n
(d)Cn(H2O)2n
Answer:
(c) Cn(H2O)n

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 31.
Which of the following compounds is found abundantly in nature ?
(a) Fructose
(b) Starch
(c) Glucose
(d) Cellulose
Answer:
(d) Cellulose

Question 32.
Glycogen, a naturally occuring polymert stored in animals is a
(a) Monosaccharide
(b) Disaccharide
(c) Trisaccharide
(d) Polysaccharide.
Answer:
(d) Polysaccharide.

Question 33.
Which of the following is a homopolymer ?
(a) Bakelite
(b) Nylon 6, 6
(c) Neoprene
(d) Buna -S
Answer:
(c) Neoprene

Question 34.
The use of chemicals for treatment of disease is called ………………….
(a) chemotherapy
(b) Physiotherapy
(c) angiotherapy
(d) polytherapy.
Answer:
(a) chemotherapy

Question 35.
Which of the following is a criteria to classify drugs ?
(a) Chemical structure
(b) Molecular targets
(c) Drug action
(d) All of these.
Answer:
(d) All of these.

Non-Objective Type Questions

Short Answer Type Questions

In this Section, there are 18 Short answer type questions (each carrying 2 marks), out of which answer any 10 questions.  2 x 10 = 20

Question 1.
How will you distinguish between Lyophobic colloid and Lyophilic colloid ?
Answer:
Lyophobic Colloids:

  • They are irreversible in nature
  • They are easily precipitated by addition of a small amount of suitable electrolyte.

Lyophilic Colloids :

  • They are. reversible in nature.
  • They are completely stable and do not easily precipitated.

Question 2.
Calculate the osmotic pressure of 5% solution of urea at 273 K.
Answer:
If the pressure applied on the solution in greater than osmotic pressure then solvent starts passing from solution into solvent. This is called reverse osmosis. The Phenomenon of reverse osmosis is generally used for purification of sea water or hare water.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 3.
Write IUPAC names of the following :
(a) K2[Ni(CN)4]
(b) [CoCl2(NH3)4]CI
Answer:
K2 [Ni(CN)4] → Potassium Tetra Cyanonicilet (III)
CoCl2 (NH3)4 Cl → Tetramine Dichloride Cobalt (III) Chloride.

Question 4.
How would you convert
(a) aniline to bromobenzene
(b) ethanal to methanamine ?
Answer:
(a) Aniline to Bromobenzene :
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.7

(b) Ethanol to methanamine :
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.6

Question 5.
Given reasons for the following :
(a) Formic acid is stronger than acetic acid.
(b) Aniline is less basic than methylamine.
Answer:
(a) Formic acid is stronger than acetic acid – In every acid its acidity depends upon donation of proton from the solution .
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.7
If the value of Ka is maximum, the acidity will be maxm-
HCOOH → Ka – 1.77 x 105
CH3COOH → Ka- 1.75 x 105
So, by the above equations it is clear that formic acid is more acidic than acetic acid.

(b) Aniline is less basic than methylamine -In aniline one pair of electron is present on nitrogen atom which is overlapped with n – electron in the ring. So, nitrogen atom is positively charged or there in lack of electrons due to this it is not in the state that it can give paired electrons to acid, in comparision with methylamine, due to this there in no overlaping. Thus, aniline is a weak base than methylamine.

Question 6.
Account for the following :
(a) The boiling point of ether is much lower than that of alcohol.
(b) Phenol is more acidic than alcohol.
Answer:
(a) The boiling point of other is much lower than that of alcohol-In the case of alcohol hydrogen bond is present between the molecules, whereas in ether there is no hydrogen bond present between their molecules. nDue to this reason, the boiling point of ether is much lower than alcohol.

(b) Phenol is more acidic than alcohol-Phenol is generally a weak acid, but it has acidic property because it gives phenoscide ion in the solution.
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.8
In the above reaction the negative charge gives stability to the phenoscide ion.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 7.
Write down the half cell reaction and cell reaction for the Daniel cell.
Zn(s) | Zn+2(aq) (1M) || Cu+2(aq) (1M) | Cu(s)
Answer:
Zn (s) → Zn2+ (aq) + Ze (half cell reaction)
Cu++ (aq) + 2e → Cu (s) (half cell reaction)
———
Zn + Cu++ (1M) → Zn++ (1M) + Cu (Complete Cell reaction)

Question 8.
Account for the following .
(a) HI is stronger acid than HF
(b) The electron affinity of fluorine is less than that of chlorine.
Answer:
(a) HI is stronger acid than HF – The bond length between HF is very small and since Fluorine is the most electronegative element of the periodic table Due to this reason HF is more electronegative which catches hydrogen strongly. On the other hand, bond-length between HI is very big because T is less electronegative than F. Due to this reason H+ ion comes out easily after Alteration.

(b) Since we know that the bond distance increases from I2 to I1 So the bond dissociation enthalpy should decrease, because of the increase in size of atom as we move from F to The F-F bond dissociation enthalpy is smaller than that of Cl-Cl and smaller than that of Br-Br. This is due to the reaseon than that of the F atom in very small and the there lone pairs of electrons on each f-atom repel the bond pair holding the F- atoms F2 molecule. I2< F2< Br2 < Cl2

Question 9.
Give definitions of the following with examples :
(a) Calcination
(b) Roasting
Answer:
(a) Calcination → The process of heating a metal- rich arc to a high temperature to convert the metal into its oxide either in absence or insufficient supply of air is called calcination.
eq: Al2 O3 . 2H2O → Al2 O3 + 2H2O
2 Al (OH)3 → Al2 O3 + 3 H2O

(b) Roasting →The process of heating a finely ground arc to a high temperature in excess of air in called roasting.
Roasting converts the metal present in the ore to its oxide.
4FeS2 -1102 → 2Fe2d3 +8SO2
2Cu2S + 3O2 → 2Cu2O + 2SO2

Question 10.
Complete the following reactions :
(a) CHCl3 + ale. KOH + C6H5NH2
(b) CH3CH2OH + I2 + NaOH →
Answer:
(a) CHCl3 + KOH+C6H5NH2 → C6H5NC+3KCl+3H20.
(b) CH3CH3OH + 412 + NaOH → CHI3 + NCOONa + 5Hl.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 11.
Differentiate between adsorption and absorption.
Answer:
Adsorption :

  • In this phenomenon, the concentration on the surface of adsorbent is different from that in the bulk.
  • It occurs only at the surface of adsorpent.

Absortion :

  • In this phenomenon, the concentration is same through out the material.
  • It occurs throughtout the body of the material.

Question 12.
What is the difference between Schottky defect’ and ‘Frenkel defect’ ?
Answer:
The difference between ‘Schottky defect’ and ‘Frenkel defect’ is stated below
Schottky defect :

  • This type of defect is created when one positive ion and one negative ion are missing from their respective positions, leaving behind a pair of holes
  • Maximum no. of Schottky defects in crystal minimizes the density
    Ex-NaCl, kCl, CsC12KBr

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.9

Frenkel defect:

  •  This type defect is created when an ion leaves its correct lattice site & occupies an intersitial site.
  • It does not give any charge in density. eg-Zns, AgCl, AgBr and Agl M

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.10

Question 13.
When 10 gm of a non-volatile solute is dissolved in 100 gm of benzene, its boiling point is raised by 1°. What is the molecular mass of the solute ? (K4 for benzene – 2-53 Km-1)
Answer:
Mass of solution (MB) = 100 g
Mass of solution (MA) = 100 g .
Mass of solution (NA) = 100 g
Raise in B.P. = ATb = 1°
Molecular mass of soluted (MB) = ?
Benzene (solution) Kh = 253 km-1 .
∵ ΔTb = Kh-m = 253 x \(\frac{10}{m_{B} \times 100} \times 1000\)
mB = 253g

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 14.
Define the following terms :
(a) Order of reaction
(b) Threshold energy.
Answer:
Define the following terms
(a) Order of reaction – It is. an important parameter for every chemical reaction, which refers to the number of reacting particles.
Order of reaction – It is defined ass the sum of powers or exponents to which the concentration terms are raised in the rate law expression.
e.g. αA + bB → Products
Rate = K[A]m[B]m then, order of reaction is = (m + n)

(b) Threshold energy—The minimum amount of energy which the colliding particles must possess in order to bring about chemical reaction is called thresholod energy.

Question 15.
Define electrochemical equivalent.
Answer:
Faraday’s 1st law of electrolysis – This law states that the mass of a substance produced at an electrode is directly proportional to the quantity of electricity passed.
m α Q  where,
m α I x t Q → quantity of elecricity.
m =Z x I x t
I → current in amperes.
t → time
Z → Electrochemical equivalent
Electrochemical – The amount of substance liberated at the electrode, when current of one ampere is passed through the electrolyte for one second.

Question 16.
If in a chemical reaction A+B product, rate law is given by R = K [A]1/2 [ B ]3/2, find the order of reaction.
Answer:
A + B → production
\(\frac{d n}{d t}=R=K[A]^{1 / 2}[B]^{3 / 2}\)
So, order of reaction \(=\frac{1}{2}+\frac{3}{2}=\frac{4}{2}=2\)

Question 17.
What is Tyndall effect ? Discuss.
Answer:
When a beam of light is passed through a colloidal solution, the beam is illuminated, such phenomena is not observed in true solution. Tyndall effect is observed when a beam of sunlight enter a earth room. Illuminating dust particles in beam scatter light.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 18.
Give the name of two copper ores.
Answer:

  • CuFe S2
  • Cu2 O

Long Answer Type Questions

There are 06 long answer type questions (each carrying 05 marks), out of which answer any there questions.             (5 x 3 = 15)

Question 19.
(a) A first order reaction is 75% completed in 60 min. Find the half-life period of the reaction.
(b) Given one example each of zero order and first order reactions.
Answer:
(a) We know that half life period \(t_{1 / 2}=\frac{0.693}{K}\)
Also, the first order expression is 2.303
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.11
Now, by putting the values of K in above equation.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.12

(b) Examples of Zero-order reaction
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.13

Question 20.
Describe the general characteristics of transition elements with special reference to the following :
(i) Formation of colour salt
(ii) Variable oxidation state.
Answer:
(i) Formation of clour salt- Majority of transition metal compounds and cloured both in solid state as well as in aqeous solution. This is contrast to the compounds of respective (s and p-block) elements wich are usually colourless.

In a transition metal atom or oil, all the five d-orbits have the same energy i. e. these are degenerate orbitals. However three out of these (dxy, dyz, dzx) orbitals differ in shape from the other two (dx2y1dz2). When ligands both neutral or anionic approach these, species, the orbital no longer degenerate, and split into two sets of orbitals. This is called crytal field splitting one set with lower energy has three orbitals (dxy, d, dzx), where as the other set with slightly higher energy has two orbitals (dx2y2, dz2).

This, Promotion of one more electrons from a set of lower energy orbitals to a set of higher energy orbitals with in the same subshell is possible in case of transition elements with partly filled (n – 1) d-subshell. Since these two sets of d-orbital belonging to the same subshell. Have slightly different energy, the energy required to promote one or more electrons is small. Radiations of light corresponding to such a small amount of energy are available with it in the visible region of the spectrum.

Thus, when white light falls on such a transition element, some radiation corresponding to certain colour are absorbed and one are more electrons are raised from lower energy set of orbitals to higher energy set of orbitals. With the abosorption or radiations corresponding to specific colour from the white light a colour known as the complementary colour is observed or is transmitted. It may be noted the transmitted colour depends upon the colour which is observed for the electronic transition.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

(ii) The oxoanions of metals have co-valent mature in which oxygen is involved in the multiple bonding with the metal atom. This is responsible for the high oxidation state of the metal in oxoamine. For example-The elements Mn exibibits +7 oxidation state in permaganate ion (MnO4_)

Question 21.
Write IUPAC names of the following :
(i) CH3CONH2
(ii) (CH3)2CHCH2COCl
(iii) CH3 – O – C2H5
(iv) Ch3CH2CN
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.14
Answer:
(i) CH3 CONH2 → Ethanamide
(ii) (CH3)2 CHCH2 CoCl -3-Methyl butanoil Chloride.
(iii) CH3 – O – C2H5 – Methoxy ethane.
(iv) CH3CH2CN — Ethyl isocyanide
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.15

Question 22.
What is polymerisation ? Define the terms addition polymerisation and condensation polymerisation. Give one example of each.
Answer:
Polymerisation-Polymerization is a Process of reacting monomer molecules together in a chemical reaction to form polymer chains or three dimensional networks. Polymerisation occurs via a variety of reaction mechanisms that vary in colexity due to functional groups presnt in reacting compounds and their inherent steric effects.

There are following two types of polarization.

  • Additional Polymerization
  • Condensation Polymerization.
  • Additional Polymerization-It is formed by the repeated addition of a large number of same or different monomers processing double and triple bonds.

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.16

(b) Condensation Polymerization- Condensation Polymers are formed by repeated condensation reaction between two bifunctional or trifunctional monomer units usually with the elimination of small molecules like water, alcohol, ammonia, Carbondioxide, hydrogen chloride, etc. and process by which condensation Polymers are formed is called condensation polymerization.
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.17

Question 23.
A element A (atomic mass = 100) having 100 structure has unit cell edge length of 400 pm. Calculate the density of A and number of unit cells in 10 cm of A.
Answer:
a (edge length) = 400 pm
Na = 6.02 x 1023
M = 100 gm / mole.
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.18

Bihar Board 12th Chemistry Model Question Paper 2 in English Medium

Question 24.
Write the following giving chemical equations :
(i) Carbylamine reaction
(ii) Wurtz reaction.
(iii) Nitration of benzene
Answer:
(i) Carbylamine reaction – Chloroform when heated with primary amine in presence of alcoholic KOH. forms a derivative called isocyanide.
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.19

(ii) Wurtz reaction – When two moles of alkyl halide is heated with Na in the presence of ether goes higher alkane.
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.20

(iii) In the presence of concentration H2SO4 benzenes reacts with cone HNO3 and it is found into benzene.
Bihar Board 12th Chemistry Model Question Paper 2 in English Medium 1.21

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Bihar Board 12th Chemistry Model Papers

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Time : 3 Hours 15 Min
Full Marks: 70

Instructions for the candidates

  1. Candidates are required to give answers in their own words as far as practicable.
  2. Figures in the right hand margin indicates full marks.
  3. While answering the questions, candidate should adhere to the words limit as far as practicable.
  4. 15 Minutes of extra time has been allotted for the candidates to read the questions carefully.
  5. This question paper is divided into two sections : Section -A and Section-B
  6. In Section A, there are 35 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with blue/black ball pen against the correct option on OMR Sheet provided to you. Do not use Whitener/Liquid/Blade/ Nail on OMR Sheet otherwise your result will be treated as invalid.
  7. In section-B, there are 18 short answer type questions (each carrying 2 marks), out of which only 10 (ten) questions are to be answered Apart from this there are 06 Long Answer type questions (each carrying 5 marks), out of which 3 questions are to be answered.
  8. Use of any electronic device is prohibited.

Objective Type Questions

In the following questions no. from 1 to 35, there is only one correct answer against each question. For each question, mark (darken) the correct answer on the OMR Sheet provided to you. (1 x 35 = 35)

Question 1.
The coordination number of metal crystallising in a hexagonal close packing is ………….
(a) 12
(b) 4
(c) 8
(d) 6
Answer:
(a) 12

Question 2.
A crystalline structure has radius ratio (r, / r) in the range of 0.225 – 0.414. The coordination number and arrangement of anions around the cations are
(a) 3, plane triangular
(b) 6, octahedral
(c) 4, tetrahedral
(d) 8, cubic
Answer:
(c) 4, tetrahedral

Question 3.
A crystal lattice with alternative +ve and -ve ions has radius ratio 0.524. The coordination number of lattice is
(a) 4
(b) 6
(c) 8
(d) 12
Answer:
(b) 6

Question 4.
A solid AB has a rock salt structure. If radius of cation A+ is 120 pm, what is the minimum value of radius of Banion ?
(a) 120 pm
(b) 240 pm
(c) 290 pm
(d) 360 pm
Answer:
(c) 290 pm

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 5.
A crystal is formed by two elements X and Y in cubic structure. X atoms are at the comers of a cube while Y atoms are at the face centre. The formula of the compound will be ………..
(a) XY
(b) XY2
(c) X2Y3
(d) XY3
Answer:
(d) XY3

Question 6.
What will be the mole fraction of ethanol in a sample of spirit containing 85% ethanol by mass ?
(a) 0.69
(b) 0.82
(c) 85
(d) 0.60
Answer:
(a) 0.69

Question 7.
What is the molarity of a solution containing 10 g of NaOH in 500 mL of solution ?
(a) 0.25 mol L-1
(b) 0.75 mol L-1
(c) 5 mol L-1
(d) 1.25 mol L-1
Answer:
(c) 5 mol L-1

Question 8.
In a cell reaction,

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 1
If the concentration of Cu2+ ions is doubled then Epell will be
(a) doubled
(b) halved
(c) increased by four times
(d) unchanged
Answer:
(d) unchanged

Question 9.
A standard hydrogen electrode thas a zero potential because
(a) hydrogen can be most easily oxidised
(b) hydrogen has only one electron
(c) the electrode potential is assumed to be zero
(d) hydrogen is the lightest element.
Answer:
(c) the electrode potential is assumed to be zero

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 10.
In a reaction 2X → Y, the concentration of X decreases from 3.0 moles/litre to 2.0 moles/litre in 5 minutes. The rate of reaction is …………
(a) 0.1 mol L-1 min 1
(b) 5 mol L-1 min-1
(c) 1 mol L_1 min-1
(d) 0.5 mol L-1 min-1
Answer:
(a) 0.1 mol L-1 min 1

Question 11.
For the reaction, 2N2O5 → 4NO2+O rate and rate constant are 1,02 x 10-4 mol Lr1 s-1 and 3.4 x 10-5 s-1  The
concentration of N9O5 in mol L-1 will be ………….
(a) 3.4 x 104
(b) 3.0
(c) 2
(d) 3.2 x 10~5
Answer:
(b) 3.0

Question 12.
The incorrect statement about physical adsorption is
(a) it lacks specificity
(b) it is generally reversible
(c) porous surfaces are good adsorbent
(d) heat of adsorption is quite high
Answer:
(d) heat of adsorption is quite high

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 13.
Which is correct in case of vander Waals adsorptions ?
(a) High temperature, low pressure
(b) High temperature, high pressure
(c) Low temperature, low pressure
(d) Low temperature, high pressure
Answer:
(d) Low temperature, high pressure

Question 14.
Which of the following is not an ore of magnesium ?
(a) Carnal lite
(b) Magnesite
(c) Dolomite
(d) Gypsum
Answer:
(d) Gypsum

Question 15.
Which of the following is not an oxide ore ?
(a) Corundum
(b) Zincite
(c) Calamine
(d) Chromite
Answer:
(c) Calamine

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 16.
Nitrogen is relatively inactive element because
(a) its atoms has a stable electronic configuration
(b) it has low atomic radius
(c) its electronegativity is fairly high
(d) dissociation energy of its molecule is fairly high
Answer:
(d) dissociation energy of its molecule is fairly high

Question 17.
Nitrogen combines with metals to form
(a) nitrites
(b) nitrates
(c) nitrosyl chloride
(d) nitrides
Answer:
(d) nitrides

Question 18.
Reactivity of transition elements decreases almost regularly from Sc to Cu because of
(a) lanthanoid contraction
(b) regular increase in ionisation enthalpy
(c) regular decrease in ionisation enthalpy
(d) increase in number of oxidation states.
Answer:
(b) regular increase in ionisation enthalpy

Question 19.
The first ionisation energies of the elements of the first transition series (Ti to Cu)
(a) increases as the atomic number increases
(b) decreases as the atomic number increases
(c) do not show any change as the addition of electrons takes place in the inner (n – 1) d-orbitals
(d) increases from Ti to Mn and then decreases from Mn to Cu
Answer:
(a) increases as the atomic number increases

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 20.
The ligand N(CH2 CH2 NH2)3 is
(a) bidentate
(b) tridentate
(c) tetradentate
(d) pentadentate
Answer:
(c) tetradentate

Question 21.
Which of the following is a tridentate ligand ?
(a) EDTA4-
(b) (COO)22-
(c) dien
(d)  NO2
Answer:
(c) dien

Question 22.
Which of the following is not correctly matched with its IUPAC name ?         .
(a) CHF2CBrClf : l-Bromo-l-chloro-1,2, 2 – trifluoro- ethane
(b) (CC13)3 CC1: 2-(Trichloromethyl)-l, 1,1,2,3,3,3 – heptachloropropane
(c) CH3C(p-ClC6H4)2CH(Br)CH3 : 2-Bromo-3,3-bis (4- chlorophenyl) butane
(d) o-BrC6H4CH(CH3)CH2CH3 : 2-Bromo-l-methyl- propropyl benzene
Answer:
(d) o-BrC6H4CH(CH3)CH2CH3 : 2-Bromo-l-methyl- propropyl benzene

Question 23.
Halogen acids react with alchols to form alkyl halides. The reaction follows a nucleophilic substitution mechanism. What will be the major product of the folowing reaction ?

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 2
Answer:
(c)

Question 24.
The best method to prepare 3-methylbutan-2-ol from 3- methylbut-l-ene is
(a) addition of water in presence of dil. H2SO4 .
(b) addition of HCl followed by reaction with dil. NaOH
(c) hydroboration-oxidation reaction
(d) Reimer-Tiemann reaction
Answer:
(a) addition of water in presence of dil. H2SO4 .

Question 25.
An alkene CH3CH = CH2 is treated with B2H6 in presence of H2O2. The final product formed is
(a) CH3CH2CHO
(b) CH3CH(OH)CH3
(c) CH3CH2CH2OH
(d) (CH3CH2CH2)3B
Answer:
(c) CH3CH2CH2OH

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 26.
Benzoyl chloride on reduction with H2/Pd – BaSO4 produces
(a) benzoic acid
(b) benzyl alcohol
(c) benzoyl sulphate
(d) benzaldehyde
Answer:
(d) benzaldehyde

Question 27.
The oxidation of toluene to benzaldehyde by chromyl chloride is called
(a) Etard reaction
(b) Riemer-Tiemann reaction
(c) Wurtz reaction
(d) Cannizzaro’s reaction
Answer:
(a) Etard reaction

Question 28.
When excess of ethyl iodide is treated with ammonia, the product is
(a) ethylamine
(b) diethylamine
(c) triethylamine
(d) tetraethylammonium iodide
Answer:
(d) tetraethylammonium iodide

Question 29.
Secondary amines can be prepared by
(a) reduction of nitro compounds
(b) reduction of amides
(c) reduction of isonitriles
(d) reduction of nitriles
Answer:
(c) reduction of isonitriles

Question 30.
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 3
(a) 2-Iodoheptane
(b) Heptane-2-ol
(c) 2-lodohexane
(d) Heptanoic acid
Answer:
(d) Heptanoic acid

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 31.
On oxidation with a mild oxidising agent like Br2/H2O, the glucose is oxidised to …………..
(a) saccharic acid
(b) glucaric acid
(c) gluconic acid
(d) valeric acid
Answer:
(c) gluconic acid

Question 32.
Which factor imparts the crystalline nature to a polymer like nylon ?
(a) Strong intermolecular farces the hydrogen bonding between chains.
(b) vander Walls forces between the polymeric chains.
(c) Close packing of the chains due to ionic bonding between the chains.
(d) Three-dimensional network of chains.
Answer:
(a) Strong intermolecular farces the hydrogen bonding between chains.

Question 33.
Arrange the following polymes in an increasing order of intermolecular forces; fibre, plastic, elastomer.
(a) Elastomer < Fibre < Plastic
(b) Elastomer < Plastic < Fibre
(c) Plastic < Elastomer < Fibre
(d) Fibre < Elastomer < Plastic
Answer:
(b) Elastomer < Plastic < Fibre

Question 34.
Antihistamines are not helpful
(a) in curing nasal allegries
(b) in treating rashes caused by itching
(c) in bringing down acute fever
(d) in vasodilation.
Answer:
(c) in bringing down acute fever

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 35.
The drugs which are given to the patients suffering from anxiety and mental tension are known as
(a) tranquilizers
(b) analgesics
(c) antimicrobials
(d) antibiotics
Answer:
(a) tranquilizers

Short Answer Type Questions

In this Section, there are 18 Short answer type questions (each carrying 2 marks), out of which answer any 10 questions.  2 x 10 = 20

Question 1.
Which methods are usually employed for purifying the following metals ?
(i) Nickel
(ii) Iron. Mention the principles.
Answer:
(i) Silesion process
(ii) Pudding process, cementation process, Bessemer’s rocess, siemens martin open heart process, Linz Donawitz process.

Question 2.
Cl, Br, I or halogens are members of which group in the periodic table ?
Answer:
Group-(ViiA)

Question 3.
Explain, why the valency of inert gases is zero.
Answer:
It is because since the valence shell is saturated with 8 electrons. The hoble gases have so a valence equal to zero as in principle can not make chemical bands with other – atoms.

Question 4.
Explain standard electrode potential.
Answer:
Standard electrode potential : It is the measure of individual potential of a reversible electorde at standard state which is with solutes at an effective concentration of 1 mol dm-3 and gases at a pressure of 1 atm.

Question 5.
What is carbocation ? Explain.
Answer:
Carbocation : A carbocation is an ion with positively-charged carbon atom. Among the simplest example methenium CH+3 ethanium C2H+2 . Some carbocations may have two or more positive charges, on the same carbon atom or on different atom such as ethylene dictation (C2H4+). It is classified in two categories according to the valence of the charged carbon.

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 6.
What do you mean by acid rain ? Explain.
Answer:
Acid rain : It is a rain or any other form of precipitation that usually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants aquatic animals and infrastructure. Acid rain is caused by emissions of sulphur dioxide and nitrogen oxide, which react with water molecules in the atmosphere to produce acids. In chemical acid rain can cause point to peel, corrosion of steel structures such as bridges and erosion of stone statues.

Question 7.
Explain two important uses of formalin.
Answer:
Two use of formaline are following:

  • It is used as preservative
  • It is also used as a disinfectation and an antibacterial.

Question 8.
How will you convert Aniline into Benzoic acid ?
Answer:
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 4

Question 9.
Any transition series contains only ten elements. Why?
Answer:
There are only 10 members because in period left to right atomic number increases and hence after a certain number when the D subshell is fully filled the electron has to go in S and P sub shell, hence it ends and P blocks

Question 10.
Explain mole fraction.
Answer:
Mole fraction : It is defined as the amount of a constituent n divided by the total amount of all constituents
in a mixture ntotal It is also called amount fraction i.e  \(\left(x_{i}=\frac{h_{i}}{n_{\text {total }}}\right)\)

Question 11.
What is salt bridge ? What are its uses ?
Answer:
Salt bridge : In electro chemistry, it is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic cell (voltaic cell, a type of electrochemical cell. Salt bridge usually comes into two types : glass tube and filter paper.
Uses : It is used in voltaic cell. Purpose of salt bridge is only to move electrons from electrotype solution to the other.

Question 12.
(a) Write the IUPAC name of the following compound :
Answer:
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 5

(b) Name the product formed when ethyne is oxidised with cold alkaline solution of KMnO4.
Answer:
(a) 2, 3 -Dimethyl butane
(b) Ethane – 1, 2 – diol
(CH2OH – CH2OH)

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 13.
If 20 g of calcium carbonate is added to a solution containing 20 g of HCl. What substances will be present when the reaction is over and what quantity of each of them will be present there?
Answer:
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 6
Thus, HCl will be present when the reaction is over. Rest amount of HCl = 20 – 14.8 = 0.56 g.

Question 14.
Write chemical reaction to obtain the following :
(i) Methane to chloroform
(ii) Chloroform to ethyne.
Answer:
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 7

Question 15.
Give reasons for the following:
(i) Ethyne is more acidic than ethane,
(ii) Lower members of aldehyde are more soluble in water.
Answer:
(i) Ethyne contains SP hybridized carbons, while ethane contain SP3 hybridized carbons. Th SP hybrid orbitals have greater S character than SP3 which allows negative charge to be held closer to the nucleus and increasing the acidic character that is why ethyne is more acidic than ethane.

(ii) Because, lower member of aldehyde have capability of forming H-bond with water molecule.

Question 16.
Transition elements form coloured compound. Explain.
Answer:
The value of electrods potential depends upon the heat of sublimation and ionisation energy AH – AHsib + IE + AHhyd. Due to.the influence of ligand d-or-bitals of transition metals divided into two unequal energy containing sets, unpaired electrons obsorb sunlight and jumps from one orbit into another orbit and oen colour is reflected.

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 17.
Why is the bond angle of PH4 more than PH 3 ?
Answer:
Because CH4 has no lone pair of electrons, while PH3 has so bond angle of CH4 (1095°) is more than PH3.

Question 18.
Give I.U.P.A.C. names of the following :
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 8
Answer:
(a) Butane-1,4 dioic acid
(b) 2-hydroxy propan-1- oic acid.

Long Answer Type Questions

There are 06 long answer type questions (each carrying 05 marks), out of which answer any there questions.
(5 x 3 = 15)

Question 19.
How does nitric acid react with the following ? Give equation.
(i) Copper
(ii) Iron.
Answer:
(i) Reaction of HNO3 with copper : (A) With not and concentrated HNO3, copper reacts to give nitrogen peroxide, copper nitrate and water
Cu + 4HNO3 → Cu(NO3 ) + 2NO2+H2O.

(ii) With 50% concentrated nitric acid copper reacts to give copper nitrate, nitric oxide and water
3Cu+ HNO3 → Cu(NO3)2 +2NO + 4H2O

(iii) With 20 – 25% dilute. HNO3 copper reacts to give copper nitrate, nitrous oxides and water.
4Cu + 10HNO3 → 4Cu(NO3)2 +N2O + 5H2O

(iv) On passing vapour of nitric acid on heated copper nitrogen gas and water vapour are obtained
5Cu + 2HNO3 → 4CuO + N2+H2O

(v) Reaction of HNO3 with Iron : (A) With cold and dilute HNO3 Iron reacts to give ferrous nitrate and ammonium nitrate
4Fe +10HNO3 → NH4NO3 +4Fe(NO3)2 + 3H2O

(B) Hot & dil nitric acid reacts with iron and gives ferric Nitrate & No gas.
2Fe + SHNO3 → 2Fe(NO3)2 +2NO↑+H2O
Fe + 6HNO3 → Fe(NO3)3 +3NO2 +3H2O

(C) With hot and cone. HNO3 Iron reacts to give ferric nitrate and nitrogen dioxide gas.
Fe + 6HNO3 → Fe(NO3)3 + 3NO2 + 3H2O

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 20.
What are the main sources of iodine ? How is iodine extracted from sea weeds ?
Answer:
Natural sources of Iodine : Due to its reactivity Iodine is not found in nature in free state its main sources are

  • sea weeds
  • chile salt puter
  • Natural brine.

Extraction of Iodine from sea weeds : Sea weeds lamineria contains iodine, Sea weed is well dried and burnt in deep pite carefully so that iodine donot get destroyed. The obtained ash is called kelp which contains 0.4 to 1.3% Iodine kelp is dissolved in water and solution is partially crystallised when less. Soluble KI and Nal remain in the mother liquor,

cone H2SO4 is added when basic sulphides despositeat the bottom, when is filtered and removed Now the filtrate is mixed with MnO2 and H2SO4 and heated iron vessel. Iodine vapourises due to the reaction and is collected Aludel. Iodine is new collected as solid after condensation.

2Nal + MnO2 +3H2SO4 -4 2NaHSO4 + MnSO4 + 2H2O+I2

Iodine obtained by this method contains CI2 and Br2 as impurifies. It is treted with KI to obtained pure Iodine
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 9

Question 21.
(a) Write only the principle for the manufacturing of sulphuric acid by contact process.
(b) Complete the following reactions-
(i) KBr + Cl2 →…………….. +……….
(ii) I2 + H2O + CI2→………….. +………..
(iii) NaOH + Cl2 → …………..+…………. +………… (Cold and dilute)
Answer:
(a) Principle-(i) The process involves the oxidation of sulphur dioxide by air in the presence of catalyst V2O5.
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 10

(ii) Sulphur trioxide is dissolved in 98% sulphuric acid, forms oleum.
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 11

(iii) Sulphuric acid of any desire concentration is prepared from oleum with water.
H2S2O7 + H2O→2H2SO4
The oxidation of SO2 is reversible process, contraction in volume and exochermic.
Hence applying i.e., Chatelier’s principle to obtained greater yield of SO3.

  • Reaction is carried out high pressure.
  • At low temperature production of SO3 should increase. But at lower temperature SO2 does not oxidise. Hence at optimum temperature 450°C catalyst V2O5 is applied.

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

(b)

  • KCI, Br2
  • HIOj, HCl
  • NaCl, NaClO3

Question 22.
(a) State Werner’s coordination theory.
(b) What are ligands ? Classify them with examples.
Answer:
(a)

  • In co-ordination compounds metals show two types of linkages (valencies) primary and secondary.
  • The primary valencies are normally ionisable and are satisfied by negative ions.
  • The secondar valencies are non-ionisable. These are satisfied by neutral molecules or negative ions. The secondary valence is equal to the co-ordination number and is fixed for a neutral.
  • The ions/groups bound by the secondary linkages to the metal have characteristic spatial arrangements corresponding to different numbers.
  • In the modem formulations, such spatial arrangements are called co-ordination polyhedra. The species with the square brackets are co-ordination entities or complexes and the ions out side the square bracket are called counter ions.
  • He further postulated that octahedral, tetrahedral and square planar geometrical shapes are more common in co­ordination compounds of transition metals. Thus [Co(NH3)6]3 +, [CoCl(NH3)5]2+and [CoCl2(NH3)4]+ are octahderal entities, while [Ni(CO)4] and [PtCl4]2- are tetrahedral and square planar respectively.

(b) The atoms or molecules or ions which donate pair of electrons to the central metal atom and thus forms co-ordinate bond with the central metal atom. Common ligands are – NH3, CO, CN-, Cl”, Br, I”, H2O etc. Ligands which can attach themselves (called ligating) through two different atoms of the same molecule are called ambident ligands or group, e.g., NO2 , SCN. They introduce linkage isomerism in the complexes.

Question 23.
Explain why
(i) Aniline dissolves in HCl.
(ii) Amines are stronger base than Ammonia
(iii) Ethylamine is more basic than Aniline
(iv) Cyclohexamine is more basic than Aniline
(v) Phenol is acidic in nature.
Answer:
(i) Aniline is somewhat basic. It is not as basic as amonia, since protonation destroys the interaction between the ring aind the lone pair on the nitrogen atom but even still it is sufficiently basic (PKb ~ 9.4) to dissolve in HCl.

(ii) The inductive effect of attached carbon chain to an amine will raise the energy of the lone pair on the nitrogen. On amines carbon will withdraw less electron density from an atom of interest that hydrogen (in amonia). That explain why alkyl amine are stronger bases than amonia.

(iii) Therefore, less electron is available in the nitrogen atom in C6H5NH2. It can easily dissociate to denote a proton, H+ by breaking -N-H bond in the amine group that attach to phenyl group. Hence aniline is a stronger acid than ethylamine.

(iv) In cyclohexamine, the electron donating group is attached to SP3 hybridized cyclohexane ring while in case of aniline it is attached with SP2 hybridized carbon containing benzene ring. Due to more S-character in benzene ring, here becomes the de localization of 7t-electrons in the ring and further the NH2– group donates more electron to the ring so that it reduces the -i-ve charge centers and stablizes the ring and moves it less acidic means basicity increases while in case of cyclohexamine, the lone pair of electron donating NH,- group is not de localised over cyclohexane ring and is available for donation, which makes the compound more basic than anile.

(v) Phenol loses its H+ when kept in an acidic medium. Due to which phenote ion is formed. This ion formed is more stable than phenol due to its resonating character. Hence phenote formation is favoured and releases of H+ make phenol acidic.

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium

Question 24.
Explain the main points in the extraction of zinc from zinc blende.
Answer:
Explain the main points in the extraction of zinc from zinc blende.
Answer:
Extraction of zinc : Reduction process involves the steps.
(i) Concentration of the ore : The ore is Crushed and made to powder. The crushed ore is concentrated by Froth floation process. The concentrated ore goes to the surface along with the froth. This is removed and dried.

(ii) Roasting: The concentrated ore is roasted in a furnace at high temp. (900°C) in presence of excess of air. In this process zinc blends is converted into ZnO.

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 12

There is chance of formation of ZnSO4 if the reaciton temperature remains low. The ZnSO4 thus formed is decomposed to give ZnO, SO2 and O2

Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 13

If calamine ore (ZnCO3) is used then it is converted to ZnO by calcination.
ZnCO3 → ZnO + CO2

(iii) Reduction: ZnO thus formed as a result of roasting or calcination is reduced by carbon. As a result at reduction Zn metal in molten state is formed.
Bihar Board 12th Chemistry Model Question Paper 5 in English Medium 14

(iv) Purification: Impure Zn is purified by the process of electrolysis, for this impure zinc rod is made anode and a rod of pure zinc is made cathode. These rods are dipped in an electrolytic cell containing ZnSO4 Zn in deposited at cathode on electrolysis. The following cell reactions occur
Zn Zn++ +2e (At anode),Zn++ +2e → Zn (At cathode)

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Bihar Board 12th Economics Model Papers

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Time : 3 Hour 15 Min
Full Marks : 100

Instructions

  1. Candidates are required to give their answers in their own words as far as practicable.
  2. Figures in the right hand margin indicate full marks.
  3. 15 minutes of extra time has been allotted for the candidate to read the questions carefully.
  4. This question paper has two sections : Section-A and Section-B.
  5. In Section-A, there are 50 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with black/blue ball pen against the correct option on OMR Sheet provided to you Do. not use Whitener/Liquid/Blade/Nail on OMR Sheet, otherwise the result will be treated as invalid.
  6. In Section-B, there are Non-objective type questions. There are 25 Short answer type questions, out of which any 15 questions are to be answered. Each question carries 2 marks. Apart froms this, there are 08 Long answer type questions, out-of which any 04 of them are to be answered. Each questions carries 5 marks.
  7. Use of any electronic device is prohibited.

Objective Type Questions

Question No. -1 to 50 have four options provided, out of which only one is correct. You have to mark, your selected option, on the OMR-Sheet. Each questiion carries 1 (one) mark. [50 x 1 = 50]

Question 1.
Who was the father of Economics ?
(a) J. B. Say
(b) Mai thus
(c) Asam Smith
(d) Joan Robinson
Answer:
(c) Asam Smith

Question 2.
How many types of elasticity of demand are these ?
(a) Three
(b) Five
(c) six
(d) seven
Answer:
(b) Five

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 3.
Which of following is a source of prodution ?
(a) Land
(b) Labour
(c) Capital
(d) All of these
Answer:
(d) All of these

Question 4.
According to whom, Economics is a science of human welfare ?
(a) Marshall
(b) samuelson
(c) J. S’. Mill
(d) Adam Smith
Answer:
(a) Marshall

Question 5.
Market price is found is ___________
(a) Long period market
(b) Short period market
(c) Very long period market
(d) None of these
Answer:
(a) Long period market

Question 6.
For Giffin goods price elasticity of demand is ___________
(a) Negative
(b) Positive
(c) Zero
(d) None of these
Answer:
(b) Positive

Question 7.
Long-run production funtion is related to ___________
(a) Law of demand
(b) Law of returns to scale
(c) Elasticity of demand
(d) Law of increasing returns
Answer:
(a) Law of demand

Question 8.
If the price of goods rises by 60% but supply increases by only 5%, the supply of goods will be ___________
(a) Elastic
(b) Inelastic
(c) Highly elastic
(d) perfectly inelastic
Answer:
(b) Inelastic

Question 9.
Which is the central problem of economy ?
(a) Distribution of resources
(b) effective utilisation of resources
(c) Economic development
(d) All of these
Answer:
(a) Distribution of resources

Question 10.
In which economy decision is taken on the basis of price mechanism ?
(a) Socialist
(b) Capitalist
(c) Mixed
(d) All of these
Answer:
(b) Capitalist

Question 11.
The cycle which increases first and after being constant starts to reduce is called?
(a) APP
(b) MPP
(c) TPP
(d) All of these
Answer:
(b) MPP

Question 12.
The quantity of goods which seller is ready to sell in a market at fixed price and time is called ?
(a) Supply
(b) Demand
(c) Elasticity of supply
(d) Elasticity of demamd
Answer:
(a) Supply

Question 13.
Central bank of India is ___________
(a) Reserve Bank
(b) State Bank
(c) Public Bank
(d) Shere market
Answer:
(a) Reserve Bank

Question 14.
Which of the following is not a fixed cost ?
(a) Insurance Premium
(b) Interest
(c) Cost of raw material
(d) Rent of the factory
Answer:
(c) Cost of raw material

Question 15.
Which of the following is a component of budget receipts?
(a) Revenue Receipts
(b) Capital receipts
(c) Both a and b
(d) None of these
Answer:
(c) Both a and b

Question 16.
Which one of the following services is included in secondary sector ?
(a) Insurance
(b) Banking
(c) Trade
(d) Manufacturing
Answer:
(d) Manufacturing

Question 17.
Demand curve generally slopes ___________
(a) Upward from left to right
(b) Downward from left to right
(c) Parallel to X-axis
(d) None of these
Answer:
(b) Downward from left to right

Question 18.
On which factor does Keynesian theory of employment depend ?
(a) Effective demamd
(b) Supply
(c) Production
(d) None of these
Answer:
(a) Effective demamd

Question 19.
Financial year in India is ___________
(a) April 1 to March 31
(b) January 1 to December 31
(c) October 1 to September 30
(d) None of these
Answer:
(a) April 1 to March 31

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 20.
Credit money is increased when CRR ___________
(a) Falls
(b) Rises
(c) Both a and b
(d) None of these
Answer:
(a) Falls

Question 21.
Narsimham committee is related to ___________
(a) Tax reforms
(b) Banking reforms
(c) Agriculture
(d) Infrastucture reforms
Answer:
(b) Banking reforms

Question 22.
Which type of currency is issued by central bank ?
(a) Currency notes
(b) Credit money
(c) Coin
(d) All the above
Answer:
(a) Currency notes

Question 23.
In which year Reserve Bank of India was established ?
(a) 1947
(b)1935
(c)1937
(d)1945
Answer:
(b)1935

Question 24.
The expenditiure which do not create assets for the government is called ___________
(a) Revenue Expenditure
(b) Capital Expenditure
(c) Both a and b
(d) None of these
Answer:
(a) Revenue Expenditure

Question 25.
For a change in which of the following there is no change in demamd ?
(a) Change in price
(b) Change in Income
(c) Change in Taste and Fashion
(d) none of these
Answer:
(a) Change in price

Question 26.
With an increase income consumers decrease the consumption of which goods ?
(a) Inferior goods
(b) Normal goods
(c) Giffin goods
(d) Both A and B
Answer:
(b) Normal goods

Question 27.
The ability of satisfying human want in goods is called its ___________
(a) Productivity
(b) Satisfaction
(c) Utility
(d) Profitability
Answer:
(a) Productivity

Question 28.
Mention the name of the curve which shows economic problem ___________
(a) Production curve
(b) Demand curve
(c) Indifference curve
(d) production possibility curve
Answer:
(d) production possibility curve

Question 29.
Consumer behaviour is studied in ___________
(a) Micro Economics
(b) Income Analysis
(c) Macro Economics
(d) None of the above
Answer:
(a) Micro Economics

Question 30.
Which of the following is studied under Micro Economics ?
(a) Individual unit
(b) Economic Aggregate
(c) National Income
(d) None of the above
Answer:
(a) Individual unit

Question 31.
Utility is related to ___________
(a) Usefulness
(b) Morality
(c) Satisfaction of human wants
(d) All of above
Answer:
(d) All of above

Question 32.
For luxury good the demand is ___________
(a) Inelastic
(b) Elastic
(c) Highly elastic
(d) perfectly inelastic
Answer:
(c) Highly elastic

Question 33.
In production function, production is a function of ___________
(a) Price
(b) Factors of production
(c) total expenditure
(d) None of these
Answer:
(b) Factors of production

Question 34.
At which time all the factors of production may be changed ?
(a) Short run
(b) Long run
(c) Very long run
(d) All the three
Answer:
(b) Long run

Question 35.
Banking Ombudsmen scheme was announced in the year ___________
(a) 1990
(b)1995
(c)1997
(d)2000
Answer:
(b)1995

Question 36.
The alternative name of opportunity cost is ___________
(a) Economic cost
(b) Equilibrium price
(c) Marginal cost
(d) Average cost
Answer:
(a) Economic cost

Question 37.
Central bank controls credit through ___________
la) Bank Rate
(b) Open market operations
(c) CRR
(d) All the above
Answer:
(d) All the above

Question 38.
Who regulates money supply ?
(a) Government of India
(b) Reserve Bank of India
(c) Commercial Banks
(d) Planning commission
Answer:
(b) Reserve Bank of India

Question 39.
For keynes, investment implies ___________
(a) Financial Investment
(b) Real Investment
(c) Both a and b
(d) None of the above
Answer:
(c) Both a and b

Question 40.
What is the duration of a Budget ?
(a) Annual
(b) Two years
(c) Five years
(d) Ten years
Answer:
(a) Annual

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 41.
The factor(s) of the production is/are ___________
(a) Land
(b) Labour
(c) Capital
(d) All of these
Answer:
(d) All of these

Question 42.
Who invented the economic science ?
(a) Kautilya
(b) Carlyle
(c) William Morris
(d) Charles Dickens
Answer:
(a) Kautilya

Question 43.
Who said ” Economics is the science of scarcity” ?
(a) Robbins
(b) Adam Smith
(c) Marshall
(d) J.S. Mill
Answer:
(b) Adam Smith

Question 44.
Who said “Economics is the science of material welfare” ?
(a) Robbins
(b) Marshall
(c) J.B.Say
(d) Senior
Answer:
(c) J.B.Say

Question 45.
On which basic has structure of economic problem been installed ?
(a) Unlimited wants
(b) Limited resources
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 46.
ForGiffen goods price elasticity of demand is ___________
(a) Negative
(b) Positive
(c) Zero
(d) none of these
Answer:
(b) Positive

Question 47.
The main reason of operating the Law of Diminishing Return is ___________
(a) Scarcity of factors
(b) Imperfect substitution between factors
(c) Both (a) and (b)
(d) none of these
Answer:
(a) Scarcity of factors

Question 48.
When supply increases more with a result of small increase in price,the nature of supply will be ___________
(a) elastic
(b) inelastic
(c) perfectly elastic
(d) perfectly inelastic
Answer:
(a) elastic

Question 49.
Which of the following is the formula for measuring the elasticity of demand ?
(a) Proportionate change in demand /Proportionate change in price
(b) Proportionate change in price/ Proportionate change in demand
(c) Change in demand/Change in price
(d) None of these
Answer:
(a) Proportionate change in demand /Proportionate change in price

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 50.
To which factor are economic problems basically related ?
(a) Choice
(b) Consumer’s selection
(c) Firm selection
(d) None of these
Answer:
(a) Choice

Non-Objective Type Questions

Short Answer Type Questions

Question no. 1 to 25 are Short answer type questions. Answer any 15 out of them. Each question carries 2 marks. (15 x 3 = 30)

Question 1.
Explain any two factors that affect price elasticity of demand.
Answer:
Factors affecting elasticity of demand are discussed below:

  1. Substitutes : When substitute of any goods is available, then demand elasticity of such goods is highly elastic because when price of these goods increases, substitutes are used in place of it. In the same way, on decrease in price of these goods, use of substitutes decrease. Tea, coffee, gas, sugar etc. are examples of subsitutes.
  2. Alternative uses : When goods could be used in only one way, its demand will be in elastic and when it would be used in many ways, its demand will be elastic, eg. coal has so many used-it can be used industries houses ralways etc. Demand of coal for railways in in elastic but for house purpose, its cheeper alternative goods like wood cooking gas etc. could be used in place of it.

Question 2.
What is mean by law of increasing returns ?
Answer:
Law of increasing returns : Increasing returns to scale occurs when a given percentage increase in all factor inputs (in some constant ratio) causes proportionately greater increase in output. In this way, if factors of production are increased by 10%, then production increases more than 10%.
Bihar Board 12th Economics Model Question Paper 3 in English Medium 1
Percentage incress in all factors

Increasing returns to scale occur due to division of labour and Percentage increase in all factors (Factor ratio remains constant) specialisation. Division of labour and specialisation increases productivity of labour. Due to increasing in size of the scale more efficient and specialised machines are used which give increasing returns to scale.

Question 3.
Where is the equilibrium price determined ?
Answer:
Commodity Price : Demand-Supply Equilibrium : Buyer wants to give the least price while the seller wants to take the maximum price of the commodity. Bargaining takes price between both the parties and at last, the price of the commodity is determined at the price where both demand for and supply of the commodity become equal. This price is called equilibrium price.
Bihar Board 12th Economics Model Question Paper 3 in English Medium 2
In following Fig. price determined of the commodity by demand and supply forces has been shown. Demand curve DD and supply curve is cuts each other at point E where price OP is determined. This price OP (or EQ) shows the equilibrium price.

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 4.
What is the difference between Micro¬Economics and Macro-Economics ?
Answer:
Micro Economics :

  1. In Micro Economics economic problems at individual level are studied e.g., one consumer, one producer, one firm
  2. Individual and individual behaviour is studied of Macro Economics.
  3. Micro economic analysis assumes macro parameter as constant.

Macro Economics :

  1. Macro Economics studies the economic units of the entire economy, e.g., national income, total consumption, general price level.
  2. Society as a whole and its behavior is studied in Macro Economics.
  3. Macro Economic analysis assumes parameters as constant.

Question 5.
State the qualities of good money.
Answer:
Follwoing are the qualities of good money :

  1. Utility : The metal with which coin is made, must bear the feature of utility. The metal must easily be accepted. Gold and silver are such metals which possess utility.
  2. Port ability: The metal with which coin is made, can easily be transferred from one place to antother. Gold and silver coins bear this feature also.
  3. Durable : Money is saved by people and hence coin should be made of such metal which is durable from saving purpose.
  4. Divisibility : Money metal should be divisible without my loss in its value. Gold and silver are such metals having the feature of divisibility.
  5. Homogeneity : All units of money should be homogeneous.
  6. Economy : Minting cost of coin should be minimum and the depreciation in the coin should be least.
  7. Stability of Value: Money metal should be stable in value i.e. price fluctuation in the metal of coin should be minimum.
  8. Liquidity: Money metal should be liquid in nature, metal should easily be converted into coins and coins can again be converted into metal on easily
  9. Cognisibility: Metal should easily be identified. Take coins on easily be traced out if metal of money is cognisible. Gold and silver are such metals having full cognisibility.

Question 6.
State the merits & demerites of Direct Taxes.
Answer:
Merits of Direct Takes :

  1. Direct takes ensure certainity. The government and the tax payer both know fairly definitely what amount are to be paid.
  2. Direct taxes are elastic whenever the government needs more revenue it may raise the rate of direct taxes.
  3. Direct taxes are progressive in nature. It increases with the increases in money income.
  4. Direct Taxes are supposed to have on educative elfect. The tax payer is concious that provides funds to the

government and is interested in seeing that they are properly used.
Demerits of Direct Taxes :

  1. Tax evasion is possible in case of direct taxes.
  2. It has narrow base or limited area of functioning.
  3. Directed taxes are numerious accounting and other formalities, have to be observed and partly, because large lump sum tax payment have to be made.

Question 7.
What is meant by Balance of Trade ?
Answer:
Balance of Trade : It is defined as the difference between exports and imports of goods. It takes into account only those transactions arising out of exports and imports of goods (the visible items). It does not consider the exchange of services between the countries.
Symbolically, BOT = Vx – Vm where Vx = value of exports.
VOT = value of imports.

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 8.
What are the different types of economic system ?
Answer:
Economic system is a structure of such institutions with which all economic activities are operated in the society. Every economy is based on an economic system which can be divided into three categories :

  1. Capitalist Economy or market Economy
  2. Socialist Economy or planned Economy
  3. Mixed Economy.

Question 9.
What is Indifference Curve ?
Answer:
Indifference curve explains the consumer’s behaviour related with the combination of two goods and this consumer’s behaviour is explained with the help of “Indifference schedule or Indifference set.” various combinations of two goods giving equal satisfactions to the consumer become the component of ‘Indifference schedule’. When indifference schedule is represented on a graph paper, we get indifference curve.

In the words of watson “An indifference schedule is the list of combination of two commodities, the list being so arranged that a consumer is indifferent to the combinations preferring more of any other”.

Question 10.
What is elasticity of demand ?
Answer:
Elasticity of Demand : Elasticity means tendency of increasing or decreasing elasticity depends on two factors-‘Nature of Goods’ and the ‘pressure on it’, when goods undergoes greater changes in response to less pressure, it is said to be ligaly elastic and when it produces less change in response to high pressure, it is said to be less elastic.

According to Marshall. “The Elasticity of demand in a market is great or small according as the amount demanded increases much or little for a given fall in price, or diminishes much or little for a given rise in price.”

Elasticity of Demand (ed) = \(\frac { Proportionate changes in quality demanded }{ Proportionate Change in price }\)

Question 11.
What do you mean by Giffen goods ?
Answer:
Giffin Goods : Giffin goods are those inferrior goods whose income effect is negative and price effect is positive. Law of demand is not applicable in case of Giffin Goods.

Question 12.
Explain the static and dynamic functions of money.
Answer:
Static Functions: Static functions are those which help the operation of the economy but those do not create movement in the economy. In this respect, the functions of money like medium of exchange, measure of value, store of value and measure of deferred payment are the static functions of money because these functions do not create any movement in economy.

Dynamic functions: The dynamic functions are those by which money acheively influences the economic system through its impact on price level interest rates, value of production distribution of wealth and income.

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 13.
How is central bank different from commercial bank ?
Answer:
Distinction between central bank and commercial bank.
Central Bank :

  1. It is an apex bank in the country which controls all other banks.
  2. Its main objective is to operate banking system in national interest. It does not work with profit earning profit.
  3. Leaving USA where 12 central Banks are working every country has only one central Bank.
  4. It is subordinate to the government.
  5. Apart from a few specific situation, it has no direct dealing with public.

Commercial Bank :

  1. It is a part of banking and works under the control of central Bank.
  2. Its main objective is to earn maximum profit with banking operations.
  3. A country has a number of commercial banks.
  4. These banks are basically banks of share holders. It may or may not be state owned.
  5. It directly deals with general public.

Question 14.
What do you mean by Returns to Scale ?
Answer:
Returns to scale refers to long run production function when none of the factors of production remains fixed. All factors of production become variable and they can be changed also. Scale production can be changed in the long run. Internal and external economies are obtained in production due to technical improvement, division of labour, specialisation etc. These economics are not permanent and they get converted to diseconomies in the continuous process of production.

In the initial stage of production, these internal and external economics give ‘Increasing Returns to scale’ but when they get converted to diseconomies at later stage of production law of diminishaing returns comes into existence. According to watson Returns to scale refers to the behaviour of total output as all inputs are varied in the same proportion and is a long run concept”.

Question 15.
What is the shape of demand curve of a firm in perfect competition ?
Answer:
Bihar Board 12th Economics Model Question Paper 3 in English Medium 3
When a demand schedule is graphically represented, we get a demand curve. It shows the inverse relationship between price and quantity demanded. Due to this inverse relationship, demand curve slopes downward from left to right. It shows that higher the price, lower will be the quantity demanded and vice versa.

Question 16.
What is the difference between trade balance and balance of payments ?
Answer:
Difference between Balance of trade and Balance of payments.
Balance of Trade :

  1. Balance of trade refers to the difference between exports and imports of goods by a country in a year.
  2. It is a narrow concept as it is a component of balance of payments.
  3. It is only a partial record. Hence, it is not a true indicator of economic relations with other countries.
  4. It may be favorably or unfavorable.

Balance of payments :

  1. Balance of payments is a statement of all economic transactions between die residents of a country and rest of the world during a year
  2. It is a wider concept
  3. It is a complete record of economic transactions with the rest of the world. Hence, it provides a true picture of the economy of a country with the rest of the world.
  4. From accounting viewpoint; it is always balanced.

Question 17.
What is equilibrium price ?
Answer:
Equilibrium price is the price at which demand and supply of a commodity are equal. It determined by the interaction of the forces of demand and supply.

Question 18.
What is the difference between substitute goods and complementary goods ?
Answer:

  1. Substitute goods : Substitute goods means is that goods which is used for each other for very one object, e.g. Tea-coffee.
  2. Complementary goods : Complementary goods means that goods which used together to fullfil a particular object, e.g. scooter petrol.

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 19.
By which percentage method elasticity of demand is measured ?
Answer:
Percentage method :
Bihar Board 12th Economics Model Question Paper 3 in English Medium 4

Question 20.
Expain the concept of Average Revenue.
Answer:
Average revenue is found by deviding the total revenue by total number of production
AR = \(\frac { TR }{ Q }\) , Where AR = Average Revenue
TR = Total Revenue, Q = Quantity

Question 21.
What are the causes of change in supply ?
Answer:
The law of supply states the there is direct relation between price and supply of a commodity other things remaining the same. The assumptin other things remaining the same means that factors other price of the goods, determining supply remains unchanged.
Causes of changes in supply :

  1. Extention of supply
  2. Contraction supply.

Question 22.
Explain different types of market.
Answer:
There are mainly three types of market :

  1. Perfect competition : Perfect competition refers to a market situation in which there are large number of buyers and sellers. The seller sell homogenous product at single uniform price through out the market.
  2. Monopoly: Monopoly refers to a market situation in which there are no close substitute of the commodity sold by the monopolist.
  3. Monopolistic competition : Monopolistic competition refers to a market situation in which there are large number of buyers and sellers. The sellers sells closely related but not identical.

Question 23.
Why is short run average cost curve U- shaped ?
Answer:
The total revenue curve of a price taking firm is an upward-slopping straight line because it changed at a constant rate. The total revenue curve of a price-taking firm passes through the origin (point U) because the total revenue of the firm becomes zero at zero output.

Question 24.
Explain firm’s equilibrium in Non-perfect competition.
Answer:
A consumer is said to be in equalibrium when he is spending his given income on various goods in such a way that maximases his satisfaction.

Question 25.
Explain the causes of downward sloping in demand curve.
Answer:
Negative slope of demand curve is due to following reasons :-

  1. Law of diminishing marginal utility Law of demand is based on law diminishing marginal utility. According to it marginal utility of a goods diminishes as an individual consumes-more units of a goods.
  2. Increase in purchasing power or Income Effect When price of a goods power of consumer increases due to which he can maintain his previous level of consumption with less expenditure. In this way, at lower prices, more goods could be purchase. On the contrary, when price of a goods increase real income of consumer decreases due to which his consumption decreases.
  3. Substitution effect Substitution effect is due to inverse relation between price and demand of a goods. Whenever there is a change in the relative prices of goods a rational consumer will be induced to substitute the relatively dearer commodity by buying the cheaper one.
  4. Change in consumer number Change in price also effects the number of consumers. When price decrease, number of consumers increases as cheaper goods can be purchased by many consumers, i.e. even those consumers start purchasing goods which were not using it earlier due to high price.

Long Answer Type Questions

Question no. 26 to 33 are Long answer type questions. Answer any 4 of them. Each question carries 5 marks. (4×5 = 20)

Question 26.
What do you mean by credit control ? Explain the methods of credit control by Central Bank.
Answer:
The most important function of the central bank is to control the credit activities of the commercial banks. Credit control refers to the increase or decrease in the value of credit money in accordance with the monetary requirement of the country. More expansion of credit money than necessary leads to the situation of inflation, greater contraction of credit money, on the other hand, might create a situation of deflation. Central bank seeks to contain credit money within reasonable limits. With Central bank keeping credit under proper control, stability in general price level and increase in output and employment can be achieved in the country.

Methods of credit control-In modern times central bank uses two types of controls to regulate the credit created by commercially banks. The following are the method of credit control by a central bank.

A. Quantitative methods-The object of the quantitative controls is to regulate the amount of bank advance. It include the following methods-

I. Bank rate-The bank rate is the rate at which the central bank discounts the first class securities of its member bank. Thus the bank rate is also called discount rate. As the central bank is only the leader of the last resort, the bank rate is normally higher than the rate of interest. The rate of interest means the rate which the commercially banks pay to the depositions a grant their deposits.

The bank rate has close relation with the market rate of interest. The central bank increases the bank rate to increase the supply of money. If there is need for contraction in money supply the bank rate is reduced. Thus the central bank control the quantum of total money supply in the country by making change in the bank rate.

This method of credit control will, however, succeed only if the other rates in the money market follow bank rate.

II. Open market operation-The cnetral bank of the country controls the supply of money through open market operations. According to De-Kock. “In the wider sense, open market operation may be held to cover the purchase or sale by the central bank in the market of any kind of paper in which it deals – whether government securities or other securities. But in the narrow sense, open market operation has come to be applied only to the purchase or sale of government securities both long term & short term.” ‘

In this operation the central bank makes sale and purchase of securities with the commercial banks of the country. If supply of money is needed to be increased the central bank starts purchasing securities from bank and if supply is needed to be reduced it starts selling securities to the banks.

III. Change in reserve ratio-It is one of the methods of credit control by the central bank. The commercial banks deposit certain percentage of their fixed deposit with the central bank & on that basis they create credit in the economy. When theh central bank desires to restrict credit, it may raise the reserve ratio and if it wants to expand the credit, the reserve ratio will be the low.
But this method of credit control has some limitations-

  1. The bank may have very large excess of reserves with them
  2. A large inflow of gold in payment against export may increase the banks lending power
  3. The government policy of keeping interest rate low may discourage the increase in reserve ratio.

IV. Liquidity ratio-The banks are required to maintain certain resources in a liquid form under the provision of the Act. This is known as statutory liquidity ratio. The charge in this ratio will cause a change in the money supply.

B. Qualitative methods-Under this system following method of credit control is adopted-

V. Credit rationing-Under this method the central bank makes rationing of credit by distribution in different sectors, of the economy according to the requirements. This method of controlling credit can be justified only as a measure to meet exceptional emergencies. Central bank makes credit rationing by three following methods-

  1. By abolition of rediscounting facilities
  2. By restriction of limit of re-discounting
  3. By fixing the quota of the loan provided by the bank to different industries.

VI. Moral persuasion-Under this method the central bank may request and persuade member banks not to use their loans for speculation or non-essential activities. This become obligatory to the banks to follow the directions of the central bank. This method of credit control may succeed on the fulfilment of the following condition.

  1. The central bank should have full control on commercial banks & money markets.
  2. The money market of the country should be developed & organised.
  3. There should be good relation between the Central Bank & other bank.

VII. Publicity-The credit creation is based on the state of mind of the people. Sometimes the Central Bank makes publicity and educates the people to control credit expansion. For this purpose central bank issues weekly statistics, periodical review of the money market condition, etc.

VIII. Selective credit control-Sometimes some selective measures such as differential discount rates, regulation of consumers credit, fixing of margin are adopted for the purpose of credit control.

IX. Direct action-The central bank is so powerful that it may take direct action against the commercial banks for their activities which lead to credit expansion for example-Central Bank refuses to rediscount for banks whose credit policy is not in accordance with the wishes of the central bank of whose borrowings from the central bank are excess in relation to their capital & reserve. The commercial banks by the central bank. In this regard various legislative measures are taken to regulate the credit.

From the above methods of credit control, it is clear that every method has its own importance. But in modern economy the importance of quantitative methods is increasing constantly.

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 27.
What do you mean by Exchange Rare ? Explain the main factors which determine exchange rate.
Answer:
Foreign exchange rate : Meaning-Foreign exchange rate refers to the rate at which one unit of currency of a country can be exchanged for the number of units of currency of another country. In other words, it is the price paid in domestic currency in order to get one unit of foreign currency. In other words, exchange rate expresses the ratio of exchange between the currencies of two countries. Hence, exchange rate is the price of a currency expressed in terms of another currency.
Important definitions:

  1. According to Sayers, “The price of currencies in terms of each other are called foreign exchange rate.”
  2. According to Crowther, “The rate of exchange measures number of units of one currency which is exchanged in the foreign market for one unit or another.”

Causes of changes in exchange rates-The market or the current rate of exchange is subject to fluctuations due to changes in demand and supply of foreign exchange in the foreign exchange market. Some of the important factors which cause fluctuations in the rate of exchange are given as following-

  1. Change in trade-The demand and supply of foreign exchange is influenced by changes in exports and imports. If exports exceed imports, demand for domestic currency increases so that rate of exchange moves in its favour. But, if imports exceed exports, the demand for foreign exchange increases and the rate of exchange will move against the country.
  2. Capital movements-Short-term or long-term capital movements also influence the exchange rate. For example, if there is a capital flow from USA for investment in India, the demand for Indian currency will increase in the foreign exchange market. As a result, the rate of exchange of India rupee in terms of US dollar will rise.
  3. Sale and purchase of securities-The stock exchange transactions, i.e., the sale and purchase of foreign securities, debentures, shares, etc., influence the demand for foreign exchange, and thereby, the exchange rate.
  4. Bank rate-The bank rate also influences the exchange rate. If bank rate is raised, more funds will flow into the country from abroad to earn high interest rate. As a result supply of foreign currency increases and the rate of exchange moves against the foreign exchange. Converse will be the case if the bank rate falls.
  5. Speculative activities-Speculation in the foreign exchange market also influences the exchange rate. If the speculators expect a fall in the value of foreign currency, they will sell that currency. As a result, rate of exchange will move against foreign currency and in favour of home currency.
  6. Political conditions-If there is political stability, strong and efficient administration foreign investment increases in the country. The demand for domestic currency will increase and the exchange rate will move in favour of the country.

Question 28.
Distinguish between Market Economy and Planned Economy.
Answer:
Following are the differences between market economy and planned economy.
Market Economy:

  1. Goods and services go where they are most in demand and force market responds quickly to peoples wants and wide variety of goods services
  2. No need for and overriding authority to determine allocation of goods and services,
  3. Producers
    and Consumers are free to make large profit greater efficiency innovation
  4. Producers and consumers are free to make changes to sait their aims,
  5. It is not competent to providing certain services
  6. It creates inequility of incomes.

Planned Economy :

  1. There is more equal distribution of wealth and income
  2. Production is for need rather than profit
  3. Long term plans can be made taking into account a range of further needs such as population changes and the environment
  4. Government is the employer of most workers and tells then how to do their jobs
  5. Planners of ten get things wrong shortages of surpluses of some goods
  6. People are poorly motivated.

Question 29.
What do you mean by Price Elasticity of Demand ? How is it measured ?
Answer:
Price elasticity of demand may be defined as the percentage change in the quantity demanded of a commodity divided by the percentage change in price of that commodity. According to Marshall. “The elasticity of demand in a market is great or small accerding as the amount demanded increase much or little for a given full in price, or diminishes much or little for a given rise in price.”

However, we can say that price elasticity of demand (PEO or Ed) is a measure used in economics to show the responsiveness, or elasticily, of the quantity demanded of a goods or service to a change in its price. More precisely it gives the percentage change in quantity demanded in response to a one percent change in price

It can be measured as follow :

  1. Percentage or Propotionate Method : According to method, for calculating the elasticity of demand, proportionate change in demand is divided by proportionate or percentage hange in price.
    Ed : (-) Proportionate change in Demand / Proportionate change in price.
  2. Point Method : This method is also called ‘Geomatric method’, to calculate elasilicity of demand at any point on the Demand curve, tangent to that potet is drawn, on the basis of geomatric method.
    Ed : (=) Lower Segment / upper segment
  3. Total Expenditure Method : In this method, amount of changes and direction of changes in total expenditure are determined as a result of change in price of commodity.
    Total expenditure : commodity price x commodity Demand.

Question 30.
Define supply. Mention the causes which determine the supply of a commodity.
Answer:
Meaning of supply : Supply of goods refers to those quantities which a seller is ready to sell at various prices at a certain point of time. Like demand, supply is also related with a certain time and price.

Definitions :

  1. According to Thomas, “The supply of goods is the quantity offered for sale in a given market
    at a given time at various prices”
  2. According to Mayers, “We may define supply as a schedule of the amount of goods that would be offered for sale at all possible prices at any one instant of time, or during any one period of time (e.g., a day, a week and so on) in which conditions of supply remain the same.”

Following are the causes of supply of commodity :

  1. Price of the commodity : There is a direct relationship between price of a commodity and its quantity supplied.
  2. Price of Related Goods : The supply of a commodity is also indirectly affected by the price of related goods.
  3. Prices of production factors : supply of a commodity is also affected by the price of factors used in the production of the commodity. It the factors price decreases, cost of production also declines, accordingly supply increases.
  4. Technological level: Technological level and its change also affects supply of the commodity. Improvement in the techniques of production reduces cost of production.
  5. Number of Firms : Market supply of a commodity also depends upon number of firms in the market increase in the number of frims results in the increase in the market supply.
  6. Goal of the firm : If the goal of the firm is to maximise profits, more quantity of the commodity will be offered at higher price.
  7. Expected Future price: Expected price change in the future also affects the supply. If the producer expects price of the commodity to rise in the near future, current supply of the commodity should reduce. On the other hand, the price is expected to fall in future, current supply increase.
  8. Government policy : “Taxation and subsidy” policy of the government also affects market supply of the commodity. Increase in taxation tends to reduce the supply, while subsidies tends to reduce the producer to provide greater supply of the commodity.

Question 31.
How is National Income estimated by Value Added Method ?
Answer:
Measurement of national income by value added method. (1) value Added Method or Product Method
First Step : Identification and Classification of Productive Enterprise : At the very first step, we are to identify and classify various productive enterprises of an economy. Broadly speaking, we can classify the economy into the following three sectors :

    1. Primary Sector
    2. Secondary Sector
    3. Tertiary Sector.
  1. Primary Sector : It is that sector which produces goods by exploiting natural resources like land, water,
    forests, mines, etc. It includes all agricultural and allied activities, such as fishing, forestry, mining and quarrying.
  2. Secondary Sector : This sector is also known
    as manufacturing sector. It transforms one type of commodity into another, using men, machines and materials. For example, manufacturing of cloth from cotton or sugar from sugarcane. ‘
  3. Tertiary Sector : This sector is also known as service sector which provides useful services to primary and secondary sectors. It consists of banking, insurance, transport, communication, trade and commerce etc.
    Second Step: Calculation of Net Value of Output: To estimate the net value added in each identified enterprise in first step the following estimates are calculated :

    • Value of Output
    • Value of Intermediate Consumption
    • Consumption of Fixed Capital, i.e., Depreciation.

Value of output is worked out by multiplying the amount of goods and services by each enterprise with their market prices. Value of intermediate consumption calculated by using the prices paid by the enterprises. Consumption of fixed capital is also estimated as per rule and regulations.
To arrive at the net value added by the enterprise, we have to deduct the following items from the value of output:

  • Value of Intermediate Consumption
  • Consumption of Fixed Capital
  • Net Indirect Taxes.

In short, Value Added = Value of Output – Intermediate Consumption – Net Indirect Taxes. By adding the net value added by all the producing enterprises in an industrial sector, we obtain net value added to that industrial sector. The sum total of net values added by all the industrial sectors in the domestic territory of the country, gives us the Net Domestic Product at Factor Cost.

Hence, Net Value Added = Value Added by Primary Sector+Value Added by Secondary Sector+Value Added by Tertiary Sector.

Thrid Step : Calculation of Net Factor Income from Abroad : The third and final step in the estimation of national income is to estimate the net factor income earned from abroad and add it to the net domestic product at factor cost. This gives us the national income.
In shot, NNPFC = NDPFC + NFIA
Bihar Board 12th Economics Model Question Paper 3 in English Medium 5

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 32.
Define central bank and explain its functions.
Answer:
Meaning of Central Bank : Central Bank of a country is the apex monetary institution which works as a pivot for the entire banking system in the economy. Central Bank as an apex monetary institution not only plays the leadership role in banking system but also puts a control on commercial banks. Central Bank frames and executes the monetary policy and is responsible for maintaining stability and economic growth in the economy.

Definitions: According to Samuelson, “Central Bank has one function. It operates to control economy, supply of money and credit.”

According to De Kock, “A Central Bank is a bank which constitutes the apex of the monetary and banking structure of its country.” According to R.P. Kent, “Central Bank is an institution, charged with the responsible of imaging the expansion and contraction of volume of money in the interest of general public welfare.”

In modern times, a proper definition of Central Bank can be given as follows :
“Central Bank is an apex institution in a country’s monetary and banking system which develops, regulates and controls the currency and credit in the country with the objective of economic development and economic stability.”
Functions of Central Bank :

(a) Monopoly in Note Issue: In modern times, central bank alone has the exclusive right to issue notes in every country of the world. The notes issued by the central bank are unlimited legal tender throughout the country.
According to De Kock, “Almost everywhere the privilege of note issue is associated with the origin and development of central banking.”

Central Bank of the country enjoys monopoly right of note issue which has following merits :

  1. It imparts uniformity in monetary system
  2. Control on paper currency becomes simple
  3. Central bank can change money supply, i.e, maintain the flexibility in system
  4. It raises public confidence in the monetary system in the economy
  5. Central bank can easily control the credit creation in the economy
  6. It becomes successful in maintaining internal or external price stability.

(b) Banker, Agent and Financial Advisor to the Government: Like general public government also needs various services and the central bank performs the same functions as banker to the government as a commercial bank provides to its customers. As a ‘Banker, Agent and Financial Advisor’ to the government central bank performs the following functions :
(1) As a Banker to the Government: As a banker to the government, central bank performs following functions :

  • Accounts : It maintains accounts of government transactions and submits the details to the government from time to time.
  • Payments : It makes payments of all government expenses from government account.
  • Debt and Loans : It arranges loans from national international level and deposit them in government account.
  • Payments of Debt and Interest: It arranges and makes payments of interest and the amount of matured debts on behalf of the government.
  • Loan to Government: It provides short-term loans to the government whenever it is required.

(2) As an Agent to the Government: It acts as an agent to the government. All dealings of economic transactions are performed by government on behalf of the central bank. Besides, central bank represents the government in various international institutions and conferences.

(3) As a Financial Advisor to the Government: Central bank advises to the government on various economic policies like deficit financing, devaluation, trade policy, foreign exchange, etc.

(c) Bank of Banks : It performs the functions of a banks to all other banks in the country. Central bank has almost the same relation with all. others banks as a commercial bank has with its customers. Central bank keep part of the cash balance of all commercial banks as deposit with a view to meeting liabilities of these banks in times of crises.

(d) Lender of the Last Resort: As banker to the banks the central bank acts as the lender of the last resort.
In other words, in case the commercial banks fail to meet their financial requirements from other sources, they can, as a last resort, approach to the central bank for loans and advances. The central bank assists such banks through discounting of approved securities and bills of exchange.

(e) Custodian of Foreign Exchange Reserves : Central bank also acts as custodian of foreign exchange reserve It is helpful in eliminating difficulties of balance of payments and in maintaining stable exchange rate. For minimising fluctations in foreign exchange rate, central bank buys or sells foreign exchange in the market.

(f) Function of Clearing House : Central bank also performs the function of a clearing house. By cleaming house function of central bank we mean settling the claims of various banks against each other with least use of cash.

(g) Credit Control: The most important function of the central bank is to control the credit activities of the commercial banks. Credit control refers to the increase or decrease in the volume of credit money in accordance with the monetary requirement of the country. More expansion of credit money-than necessary leads to the situation of inflation.

(h) Development Related Functions : For promoting economic development central bank performs following functions :

  1. It extends organised banking system and established new financial institutions
  2. It ensures sufficient money supply for development activities
  3. Adopts cheap money policy for inducing investment.

(I) Other Functions :

  1. collection of statistics
  2. Relations with International Financial Institution
  3. Survey of Banks
  4. Arranging seminars.

Bihar Board 12th Economics Model Question Paper 3 in English Medium

Question 33.
What is law of diminishing marginal utility ? Explain its importance and limitations.
Answer:
Law of diminishing marginal utility also called law of supply, is an important law of consumption which is universally accepted.
According to this law, as we go on utilising standard additional units of a commodity continuously, marginal utility obtained from use of every additional unit decreases. It occures or happens in all goods and services. Therefore, this law is called fundamental and universal law of satisfaction. According to marshall, The additional benefit which a person derives from a given stock of a thing diminishes with evey increase in the stock that he already has”
Conditions or Assumptions of the Law :

  1. Consumption of goods should be continuous. In case of time gap, this law is not applicable.
  2. Size of consumptions units should be proper. Small size of unit increases marginal utility
  3. Price of available substitutes of goods should be stable
  4. Income and consumptions propensity of consumer should remain constant
  5. All units of consumptions should be homogeneous. In case of heterogeneity of units, law becomes in applicables.
  6. No change should take place in fashion, nature and interests of consumer.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Bihar Board 12th Physics Model Papers

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Instructions for the candidates :

  1. Candidates are required to give answers in their own words as far as practicable.
  2. Figures in the Right-hand margin indicates full marks.
  3. While answering the questions, candidates should adhere to the words limit as far as practicable.
  4. 15 Minutes of extra time has been allotted to read the questions carefully.
  5. This question paper is divided into two sections : Section -A and Section-B
  6. In Section A there are 35 Objective type questions which are compulsory, each carrying 1 mark. Darken the circle with Blue/Black ball pen against the correct option on OMR Sheet provided to you. Do not use Whitener/Liquid/ Blade/Nail on OMR Sheet, otherwise, your result will be treated as invalid.
  7. In section-B, there are 18 Short answer type questions (each carrying 2 marks), out of which only 10 (ten) questions are to be answered Apart from this there are 06 Long Answer type questions each carrying 5 marks, out of which 3 questions are to be answered.
  8. Use of any electronic device is prohibited.

Bihar Board 12th Physics Model Question Paper 1 in English Medium

Time : 3 Hours 15 Minute
Total Marks : 70

Objective Type Questions

There are 1 to 35 objective type questions with 4 options. Choose the correct option which is to be answered on OMR Sheet. (35 x 1 = 35)

Question 1.
Torque acting on dipole in electric field E is
\((a) \overrightarrow{\mathrm{p}} \times \overrightarrow{\mathrm{E}}
(b) \overrightarrow{\mathrm{P}} \cdot \overrightarrow{\mathrm{E}}
(c) \overrightarrow{\mathrm{E}} \times \overrightarrow{\mathrm{P}}
(d) P/E\)
Answer:
\((a) \overrightarrow{\mathrm{p}} \times \overrightarrow{\mathrm{E}}\)

Question 2.
The algebraic sum of currents meeting at a point in the electric circuit becomes
(a) Infinity
(b) Positive
(c) Zero
(d) Negative
Answer:
(c) Zero

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 3.
The density of metal is d and sp. resistance is r. It is in the form of wire whose length is 1 and resistance is R. The resistance mass of metal should be
Bihar Board 12th Physics Model Question Paper 3 in English Medium 1
Answer:
(a)

Question 4.
The emf of cell is measured by
(a) Voltmeter
(b) Ammeter
(c) Galvanometer
(d) Potentiometer
Answer:
(d) Potentiometer

Question 5.
The balancing point is obtained in potentiometer by increasing the length of wire
(a) On minimum length
(b) On maximum length
(c) On the same length
(d) Indefinite
Answer:
(b) On maximum length

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 6.
If two cells of E1 and E2 are balanced at length l1 and l2 in potentiometer wire then
Bihar Board 12th Physics Model Question Paper 3 in English Medium 2
Answer:
(b)

Question 7.
The phase difference between current and emf in the condition of resonance is
(a) π/2
(b) π/4
(c) π
(d) zero
Answer:
(d) zero

Question 8.
A copper ring lies in horizontal place. A bar magnet lies along its axis above the ring. The bar magnet is now released then
(a) Acceleration of the bar will be ‘g’
(b) Copper ring will go an cooling
(c) The acceleration of bar will be less than g
(d) The velocity of the bar will become upward
Answer:
(a) Acceleration of the bar will be ‘g’

Question 9.
The induced emf of rod is
(a) BLV
(b) B2L2V
(c) Zero
(d) None of these
Answer:
(c) Zero

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 10.
The energy due to flow of current I in inductance L is
\((a) Zero
(b) \frac{1}{2} \mathrm{LI}^{2}
(c) \frac{1}{2} \mathrm{LI}
(d) \frac{1}{2} \mathrm{L}^{2} \mathrm{I}^{2}\)
(a) Zero
Answer:
\((b) \frac{1}{2} \mathrm{LI}^{2}\)

Question 11.
The power loss in A.C. circuit is
(a) only resistance
(b) only capacity
(c) only inductance
(d) All of these
Answer:
(a) only resistance

Question 12.
The unit of mutualinductance is
(a) Weber
(b) Ohm
(c) Henry
(d) Gauss
Answer:
(c) Henry

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 13.
If the real and apparent power of A.C. circuit is PT and PA respectively then power factor is
\((a) \frac{P_{T}}{P_{A}}
(b) \mathrm{P}_{\mathrm{T}} \times \mathrm{P}_{\mathrm{A}}
(c) \frac{\mathrm{P}_{\mathrm{A}}}{\mathrm{P}_{\mathrm{T}}}
(d) \mathrm{P}_{\mathrm{A}}+\mathrm{P}_{\mathrm{T}}$\)
Answer:
\((a) \frac{P_{T}}{P_{A}}\)

Question 14.
Which have minimum wave length in the following?
(a) x-ray
(b) y-ray
(c) Micro wave
(d) Radio-wave
Answer:
(b) y-ray

Question 15.
A Thin prism \(\left(\mu=\frac{3}{2}\right)\) in air is immersed in water \(\left(\mu=\frac{6}{4}\right)\). The ratio of angle of deviation in both condition will be
\((a) \frac{15}{8}
(b) \frac{8}{15}
(c) \frac{5}{2}
(d) \frac{2}{5}\)
Answer:
\((c) \frac{5}{2}\)

Question 16.
The refractive index of material of prism is ^3 • The minimum deviation for this prism is :
(a) 30°
(b) 37°
(c) 45°
(d) 60°
Answer:
(d) 60°

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 17.
The cause of coloured thin film is
(a) Scattering
(b) Interference
(c) Dispersion
(d) Diffraction
Answer:
(b) Interference

Question 18.
The radius of curvature of double convex lens is 20cm and μ = 1.5 then its power is
(a) 5D
(b) 10D
(c) 25D
(d) 20D
Answer:
(a) 5D

Question 19.
The vertical section of cornea is not symmetrical about their axis. The defects of vision in eye is called
(a) Short sightedness
(b) Hypermetropia
(c) Presbyopia
(d) Astigmatism
Answer:
(c) Presbyopia

Question 20.
The radius of curvature of plane mirror is
(a) Infinity
(b) Zero
(c) +5 cm
(d) -5 cm
Answer:
(a) Infinity

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 21.
The ratio of intensity of two waves is 9:1 produces interference. The ratio of maximum and minimum intensity will be
(a) 10 : 8
(b) 9 : 1
(c) 4 : 1
(d) 2 : 1
Answer:
(c) 4 : 1

Question 22.
If the frequency of photon incident on the metallic surface becomes double then maximum kinetic energy of emitted electrons will be
(a) double
(b) more than double
(c) not change
(d) none of these
Answer:
(b) more than double

Question 23.
The photo electric effect supports
(a) Wave nature of light
(b) Particle nature of light
(c) Dual nature of light
(d) None of these
Answer:
(a) Wave nature of light

Question 24.
The electron in hydrogen atom comes from third orbit to second orbit, then released energy is
(a) 1.5 leV
(b) 3.4 eV
(c) 1.89 eV
(d) 0.54 eV
Answer:
(c) 1.89 eV

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 25.
The angular momentum of electron in hydrogen atom in lowest energy level is
\((a) \frac{h}{\pi}
(b) \frac{h}{2 \pi}
(c) \frac{2 \pi}{h}
(d) \frac{\pi}{h}\)
Answer:
\((b) \frac{h}{2 \pi}\)

Question 26.
In nuclear reactor the controlling rods are made up
(a) of Cadmium
(b) of Uranium
(c) of Graphite
(d) of Plutonium
Answer:
(a) of Cadmium

Question 27.
Which is unstable?
(a) neutron
(b) proton
(c) electron
(d) α-particle
Answer:
(a) neutron

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 28.
The Boolean expression of NOR gate is
(a) A + B = y
(b) \(\overline{\mathrm{A.B}}=y\)
(c) A.B = y
(d) \(\overline{\mathrm{A+B}}=y\)
Answer:
\((d) [latex]\overline{\mathrm{A+B}}=y\)

Question 29.
In figure logic gate is
Bihar Board 12th Physics Model Question Paper 3 in English Medium 3
(a) OR
(b) NOR
(c) NAND
(d) AND
Answer:
(d) AND

Question 30.
The majority current carrier in p-type semiconductor is
(a) electron
(b) hole
(c) photon
(d) proton
Answer:
(b) hole

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 31.
The semi conductor behaves at absolute temperature
(a) fully conductor
(b) fully insulator
(c) super conductor
(d) semi conductor
Answer:
(b) fully insulator

Question 32.
The conduction band are empty in
(a) Insulator
(b) Semi conductor
(c) In metal
(d) None of these
Answer:
(b) Semi conductor

Question 33.
Which is not the example of digital communications?
(a) E-mail
(b) Cellular phone
(c) Television
(d) Communication satellite
Answer:
(c) Television

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 34.
The value of amplitude modulation index is
(a) Always zero
(b) between 1 and
(c) Between 0 and 1
(d) Always infinity
Answer:
(c) Between 0 and 1

Question 35.
The relation between a and P in transistor is
Bihar Board 12th Physics Model Question Paper 3 in English Medium 4
Answer:
(b)

Non-Objective Type Questions
Short Answer Type Questions-

Q.No. 1 to 18 are short answers type question. Each question carries 2 marks. Answer any ten (10) question.

Question 1.
What is Electrostatic shielding?
Answer:
The electrostatic shielding is the best way to protect some area in vaccum from the influence of external electric field. ,
The technique of electrostatic shielding is applied basically in designing the cable for television.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 2.
What is polar and non polar dielectrics?
Answer:
Non-Polar dielectric :
A dielectric, in the atom or molecule of which, the centre of gravity of positive and negative charge coincide is called non-polar dielectric. Due to zero separation between +ve and -ve charges the electric dipole moment of such atom or molecules is zero.

Polar dielectric :
A dielectric, in the atom or molecules of which the centre of gravity of +ve and -ve charge do not coincide, is called polar dielectric

eg-NH3, HC1, H2O, CO2 etc.

Due to finite separation +ve and -ve charges, such atoms or molecules possess a finite electric dipole moment.

Question 3.
What is current density? Write its S.I. unit and dimension.
Answer:
Current per unit area is called current density. It is denoted by ‘J’
\(\mathrm{J}=\frac{1}{\mathrm{A}}\)

It is a vector quantity
S.I. unit : Ampere/m2
Dimension : [M°L-2 T°]

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 4.
Write two factors on which resistivity of conductor depends.
Answer:
The resistivity of conductor depends upon following factors :

  • It depends upon temperature,
  • It depends upon nature of substance of conductor.

Question 5.
Calculate the value of I in given circuit.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 5
Answer:
According to figure
R1 and R2 are in series
Rs = R1 + R2
Rs = 30 + 30 = 60Ω
Now, R3 and Rs are in parallel

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 6.
Write Lenz’s law for electromagnetic induction.
Answer:
Lenz’s law: This law states that whenever electric current is produced in circuit or in coil due to electromagnetic induction then it opposes that causes due to which it is produced.
\(\mathrm{e}=-\mathrm{n} \frac{\mathrm{d} \phi}{\mathrm{dt}}\)
e = induced emf

This law obeys the principle of Conservation of Energy.

Question 7.
Write two applications of ultraviolet waves.
Answer:

  • They are used to preserve food stuff and make drinking water free from bacteria, as these rays can kill bacteria, germs etc.
  • They are used for sterlizing surgical instruments.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 8.
The power of two lens are 12 D and -2D are kept in contact. What is the focal length of combination.?
Answer:
Power of combination P = P1 + P2
P = 12 – 2 = 10
Focal length of combination
\(f=\frac{1}{p}=\frac{1}{10} \times 100=10 \mathrm{cm} ; f=10 \mathrm{cm}\)

Question 9.
Write Brewter’s law.
Answer:
This law states that when the unpolarised light is incident on the surface on polarising angle then refractive index of medium is equal to tangent of polarising angle.
\(\mu=\tan i_{p}\)

Question 10.
State properties of photon.
Answer:
Properties of photon are as follows :

  • A photon travels with a speed of light in vacuum.
  • A photon has zero rest mass.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 11.
State two uses of photo diode.
Answer:

  • They are used as photo detectors to detect intensity of radiation.
  • They are used as light operated switches.

Question 12.
What is Binding Energy per nucleon?
Answer:

  • The binding energy per nucleon of a nucleus is the binding energy divided by the total number of nucleons.

B.E./Nucleon =
\(\frac{\Delta m \times 931 \mathrm{ev}}{\Delta}\)

Question 13.
What are limitations of amplitude modulation?
Answer:

  • The quality of audio signal is not good,
  • The atmospheric and industrial noise affect the audio signal,
  • The efficiency of amplitude modulation is low.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 14.
Write the differences between N-type and P- type semi-conductor.
Answer:
N-type :

  • when pentavalent impurity atom like As, Sb etc. are added in the intrinsic semi-conductor we get N- type of semi-conductor.
  • The majority carriers in the N-type semi-conductor are electrons and minority carriers are hole.
  • ne >> n0

P-type:

  • When invalent impurity atoms like Gallium, Indium etc. are added in the intrinsic semi-condcutor we get p-type of semi conductors.
  • The majority carriers in P-type semiconductor are holes and minority carriers are electrons.
  • nh >>ne

Question 15.
What are base band and band width?
Answer:
Base Band:
In telecommunication and signal processing it describes channel and system what range of frequency is measured from zero Hz to cut off frequency.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Band Width :
It refers to the frequency range our which as equipotent rates on the portion of spectrum occupied by the signal.

Question 16.
Define Electric Intensity. Write its S.I. unit and dimension.
Answer:
Electric Intensity :
The electric intensity at a point in the electric field is defined as the force which is experienced by unit positive charge placed at the point. It is denoted by \(\vec{E}\)
\(\vec{E}=\frac{\vec{F}}{q_{0}}\)

S.I. unit : Newton/Coulomb
or
Volt/metre
Dimension : [MLT3I-1]

Question 17.
Write properties of electric lines of force.
Answer:

  • The electric lines of force originated from positive charge and terminate on negative charge.
  • The electric lines of force never intersect to each other.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 18.
Why internal resistance of secondary cell is low?
Answer:
As in secondry cell, distance between two plates is greater and their size are big. There is no polarisation in secondary cell. Due to this, internal resistance of secondary¬cell is 10w.

Long Answer Type Questions

Q.No. 19 to 24 are long answers type question. Each question of this category carries 5 marks. Answer any three (3) question. (3 x 5 = 15)

Question 19.
State and Prove Gauss’s Theorem in electrostatics.
Answer:
Statement of Gauss’s Theorem : The net- outward normal electric flux through any closed surface of any shape is equal to l/ε0 times the total charge contained within that surface i.e.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 6

where indicates the surface integral over the whole

of the closed surface. Σq is the algebraic sum of all the charges (i.e. net charge in Coulombs) enclosed by surface S.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 7

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Proof of Gauss’s Theorem :
Let a point charge + q coulomb be placed at O within the closed surface. Let E be the electric field strength at P. Let OP=r and the permitivity of free space or vacuum be e0.

Consider a small area’ \(\overrightarrow{d S}\) of the surface surrounding the point P. Then the electric flux through \(\overrightarrow{d S}\) is given by
Bihar Board 12th Physics Model Question Paper 3 in English Medium 8

subtended by area dS at point O. Here 0 is the angle between \(\overrightarrow{d S}\) and \(\overrightarrow{E}\)

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Hence electric flux through whole of the closed surface.
\(\phi=\oint_{S} \overrightarrow{\mathrm{E}} \cdot \overrightarrow{\mathrm{dS}}=\frac{q}{4 \pi \varepsilon_{0}} \times \oint d \Omega\)

But \(\oint d \Omega\) is the solid angle due to the entire closed surface S at an internal point O = 4π
∴ \( \quad \phi=\frac{q}{4 \pi \varepsilon_{0}} \cdot 4 \pi=\frac{1}{\varepsilon_{0}} q\)

It there are several charges, + q1, + q2, + q3 + q1 – q2 – q3 ………… inside the closed surface, each will contribute to the total electric flux. For positive charges the flux will be outward and hence positive; for negative charges the flux will be inward and negative. Therefore, the total electric flux in such a case
Bihar Board 12th Physics Model Question Paper 3 in English Medium 9

where Zq is the algebraic sum of the charges within the closed surface.

Hence total electric flux through any closed surface is equal to l/e0 times the total charge (in Coulomb) enclosed within the surface which is Gauss’s law.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 20.
Find an expression for the capacitance of a parallel plate capacitor when a dielectric slab of dielectric constant K and thickness \(t=\frac{d}{2}\) but of same area on the plates is inserted between the capacitor plate. (d = separation between the plates).
Answer:
Consider a paralled plate capacitor, area of each plate being A, the separation between the plates being d. Let a dielectric slab of dielectric constant K and thickness t < d be placed between the plates. The thickness of air between the plates is (d – t). If charges on plates are + Q and -Q, then surface charge density
Bihar Board 12th Physics Model Question Paper 3 in English Medium 10

The electric field between the plates in air,
\(\mathrm{E}_{1}=\frac{\sigma}{\varepsilon_{0}}=\frac{Q}{\varepsilon_{0} \mathrm{A}}\)

Bihar Board 12th Physics Model Question Paper 3 in English Medium

The electric field between the plates in slab,
\(\mathrm{E}_{2}=\frac{\sigma}{\mathrm{K} \varepsilon_{0}}=\frac{Q}{\mathrm{K} \varepsilon_{0} \mathrm{A}}\)

∴ The potential difference between the plates VAB = work done in carrying unit positive charge from one plate to another
= Σex (as field between the plates is not constant).
Bihar Board 12th Physics Model Question Paper 3 in English Medium 11

∴ Capacitance of capacitor.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 12

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Question 21.
State Biot-Savart law, giving the mathematical expression for it.
Use this law to derive the expression for the magnetic field due to a circular coil carrying current at a point along it axis.
How does a circular loop carrying current behave as a magnet?
Answer:
(i) Magnetic field at the axis of a circular loop : Consider a circular loop of radius R carrying current I, with its plane perpendicular to the plane of paper. Let P be a point of observation on the axis of this circular loop at a distance x from its centre O. Consider a small element of length dl of the coil at point A. The magnitude of the magnetic induction \(\overrightarrow{\mathrm{dB}}\) at point P due to this element is given by
Bihar Board 12th Physics Model Question Paper 3 in English Medium 13

The direction of \(\overrightarrow{\mathrm{dB}}\) is perpendicular to the plane containing \(\overrightarrow{\mathrm{dl}}\) and \(\overrightarrow{\mathrm{r}}\) is given by right hand screw rule. As the angle between \(\overrightarrow{\mathrm{dl}}\) and \(\overrightarrow{\mathrm{r}}\) is 90°, the magnitude of the magnetic induction \(\overrightarrow{\mathrm{dB}}\) is given by,
\(\overrightarrow{\theta B}=\frac{\mu_{0} t}{4 \pi} \frac{d \sin 9 \sigma^{0}}{r^{2}}=\frac{\mu_{0} d t^{2}}{4 \pi^{2}}\) …….(ii)

Bihar Board 12th Physics Model Question Paper 3 in English Medium

If we consider the magnetic induction produced by the whole of the circular coil, then by symmetry the components of magnetic induction perpendicular, to the axis will be cancelled out, while those parallel to the axis will be added up. Thus the resultant magnetic induction \(\overrightarrow{\mathrm{B}}\) at axial point P is along the axis and may be evaluated as follows :

The component of \(\overrightarrow{\mathrm{dB}}\) along the axis,
Bihar Board 12th Physics Model Question Paper 3 in English Medium 15

Therefore the magnitude of resultant magnetic induction at axial point P due to the whole circular coil is given by
Bihar Board 12th Physics Model Question Paper 3 in English Medium 16

Question 22.
Derive an expression for the force per unit length between two long straight parallel current carrying conductors. Hence define S.I. unit of current (ampere).
Answer:
Suppose two long thin straight conductors (or wires) PQ and RS are placed parallel to each other in vacuum (or air) carrying currents I1 and I2 respectively. It has been observed experimentally that when the current in the wire are in the same direction, they experience an attractive force (fig. a) and when they carry currents in opposite directions, they experience a repulsive force (fig. b). Let the conductors PQ and RS carry currents I1 and I2 in same direction and placed at separation r. (fig). Consider a current-element ‘ab’ of length AL of wire RS. The magnetic field produced by current-carrying conductor PQ at the location of other wire RS.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

\(\mathrm{B}_{1}=\frac{\mu_{0} \mathrm{l}_{1}}{2 \pi r}\) ……………………… (i)

According to Maxwell’s right hand rule or right hand palm rule no. I, the direction of B l will be perpendicular to the plane of paper and directed downward. Due to this magnetic field, each element of other wire experiences a force. The direction of current element is perpendicular to the magnetic field; therefore the magnetic force on element ab of length ΔL.
\(\Delta F=\mathrm{B}_{x} \mathrm{I}_{2} \Delta \mathrm{L} \sin 90^{\circ}=\frac{\mu_{0} \mathrm{I}_{1}}{2 \pi r} \mathrm{I}_{2} \Delta \mathrm{L}\)

∴ The total force on conductor of length L will be
\(\mathrm{F}=\frac{\mu_{0} \mathrm{I}_{1} \mathrm{I}_{2}}{2 \pi r} \Sigma \Delta \mathrm{L}=\frac{\mu_{0} \mathrm{I}_{1} \mathrm{I}_{2}}{2 \pi r} \mathrm{L}\)

∴ Force acting on per unit length of conductor
\(f=\frac{F}{L}=\frac{\mu_{0} I_{1} I_{2}}{2 \pi r} N / m\)

According to Flemming’s left hand rule, the direction of magnetic force will be towards PQ i.e., the force will be attractive.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 17

On the other hand if the currents I1 and I2 in wires are in opposite directions, the force will be repulsive. The magnitude of force in each case remains the same.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Definition of S.I. unit of Current (ampere):
In S.I. system of fundamental unit of current ‘ampere’ has been define assuming the force between the two currents carrying wires as standard.

The force between two parallel currents carrying conductors of separation r is
Bihar Board 12th Physics Model Question Paper 3 in English Medium 18

Thus I ampere is the current which when flowing in each of parallel conductors placed at separation I m in vacuum exert a force of 2 x 10-7 on 1 m length of either wire.

Question 23.
With the help of a ray diagram, show the formation of image of a point object by refraction of light at a spherical surface separating two media of refractive indices n1 and n2 (n2 > n1), respectively. Using this diagram, derive the relation \(\frac{n_{2}}{v}-\frac{n_{1}}{u}=\frac{n_{1}-n_{1}}{R}\)

Write the sign conventions used. What happens to the focal length of convex lens when it is immersed in water?
Answer:
Formula for Refraction at Spherical Surface Concave Spherical Surface :
Let SPS’ be a spherical refracting surface, which separates media ‘1’ and ‘2’. Medium ‘ 1’ is rarer and medium ‘2’ is denser. The refractive indices of media ‘1’ and ‘2’ are n1 and n2 respectively (n1 < n2). Let P be the pole and C the centre of curvature and PC the principal axis of spherical refracting surface.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 19

O is a point-object on the principal axis. An incident ray OA, after refraction at A on the spherical surface bends towards the normal OAN and moves along AB. Another incident ray OP falls on the surface normally and hence passes undeviated after refraction. These two rays, when produced backward meet at point I on principal axis. Thus I is the virtual image of O.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Let angle of incidence of ray OA be / and angle of refraction be r i.e.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 20

If point A is very near to P, then angles i, r, a, P, Y will be very small, therefore sin i = i and sin r = r
From equation (iii)
\(\frac{i}{r}=\frac{n_{2}}{n_{1}}\)
Substituting values of i and r from (i) and (ii) we get
\(\frac{\gamma-\alpha}{\gamma-\beta}=\frac{n_{2}}{n_{1}} \text { or } n_{1}(\gamma-\alpha)=n_{2}(\gamma-\beta) \quad \ldots \text { (iv) }\)

The length of perpendicular AM dropped from A on the principal axis is h, i.e. AM = h. As angles a, P and y are very small, therefore
tana = α, tan β = β, tan γ = γ
Substituting these values in equation (iv)
n1 (tanY-tanoO = /j2(tanY-tanP) ……………. (v)
As point A is very close to P, point M is coincident with F
Bihar Board 12th Physics Model Question Paper 3 in English Medium 21

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Let u, v and R be the distance of object O, image I and centre of curvature C from pole P. By sign convention PO, PI and PC are negative i.e. u = – PO, v = – PI and R = – PC

Substituting these values in (vii) we get
Bihar Board 12th Physics Model Question Paper 3 in English Medium 22

Question 24.
Derive Einstein’s photoelectric equation ^
\(\frac{1}{2}\)
\(m v^{2}=h v-h v_{0}\)
Answer:
Einstein’s Explanation of Photoelectric Effect: Einstein’s Photoelectric Equation :

Einstein explained photoelectric effect on the basis of quantum theory.
Bihar Board 12th Physics Model Question Paper 3 in English Medium 23

The main points are :

1. Light is propagated in the form of bundles of energy. Each bundle of erergy is called a quantum or photon and has energy hv, where h = Plank’s constant and v = frequency of light.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

2. The photoelectric effect is due to collision of a photon of incident metal light and a bound electron of the metallic cathode.

3. When a photon of incident light falls on the metallic surface, it is completely absorbed. Before being absorbed it penetrates through a distance of nearly 10-8 m (or 100 A). The absorbed photon transfers its whole energy to a single electron. The energy of photon goes in two parts : a part of energy is used in releasing the electron from the metal surface (i.e., in overcoming work function) and the remaining part appears in the form of kinetic energy of the same electron.

If v be the frequency of incident light, the energy of photon = hv. If W be the work function of metal and Ek the maximum kinetic energy of photoelectron, then according to Einstein’s explanation.

hv = W + EK
or, EK = hv – W …………………….(i)

This is called Einstein’s photoelectric equation.

If v0 be the threshold frequency, then if frequency of incident light is less then v0, no electron will be emitted and if the frequency of incident light be v0, then Ek = 0; so from equation (i)
0 = hv0 – W or W = hv0

If λ0 be the threshold wavelength, then \(v_{0}=\frac{c}{\lambda_{0}}\), where c is the speed of light in vacuum.

∴ Work function
\(\mathrm{W}=h v_{0}=\frac{h c}{\lambda_{0}}\) ………………… (ii) Substituting this value in equation (i), we get
Ek = hv – hv0 ……………….(iii)
This is another form of Einstein’s photoelectric equation.

Bihar Board 12th Physics Model Question Paper 3 in English Medium

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Bihar Board 12th Biology Objective Questions and Answers

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 1.
Science of cultivation, breeding, marketing and arrangement of flowers is called
(a) arboriculture
(b) floriculture
(c) horticulture
(d) anthology
Answer:
(b) floriculture

Question 2.
Nonessential floral organs in a flower are
(a) sepals and petals
(b) anther and ovary
(c) stigma and filament
(d) petals only.
Answer:
(a) sepals and petals

Question 3.
The stamens represent
(a) microsporangia
(b) male gametophyte
(c) male gametes
(d) microsporophylls.
Answer:
(d) microsporophylls

Question 4.
Anther is generally
(a) monosporangiate
(b) bisporangiate
(c) letrasporangiate
(d) trisporangiate.
Answer:
(c) letrasporangiate

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 5.
The anther wall consists of four wall layers where
(a) tapetum lies just inner to endothecium
(b) middle layers lie between endothecium and tapetum
(c) endothecium lies inner to middle layers
(d) tapetum lies next to epidermis.
Answer:
(b) middle layers lie between endothecium and tapetum

Question 6.
The innermost layer of anther is tapetum whose function is
(a) dehiscence
(b) mechanical
(c) nutrition
(d) protection.
Answer:
(c) nutrition

Question 7.
Callase enzyme which dissolves callose of pollen tetrads to separate four pollens is provided by
(a) pollens
(b) tapetum
(c) middle layers
(d) endothecium.
Answer:
(b) tapetum

Question 8.
In angiosperms various stages of reductional division can best be studied in
(a) young anthers
(b) mature anthers
(c) young ovules
(d) endosperm cells.
Answer:
(a) young anthers

Question 9.
Study of pollen grains is called
(a) micrology
(b) anthology
(c) palynology
(d) pomology
Answer:
(c) palynology

Question 10.
Several pollen grains form a unit designated as pollinium in Family
(a) Asteraceae
(c) Asclepiadaceae Pollen
(b) Cucurbitaceae
(d) Brassicaceae
Answer:
(c) Asclepiadaceae Pollen

Question 11.
Pollen grain is a
(a) megaspore
(b) microspore
(b) microspore
(d) microsporangium.
Answer:
(b) microspore

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 12.
How many pollen mother cells should undergo meiotic division to produce 64 pollen grains ?
(a) 64
(b) 32
(c) 16
(d) 8
Answer:
(c) 16

Question 13.
How many meiotic divisions are required for the formation of 100 pollen grains ?
(a) 100
(b) 50
(c) 25
(d) 26
Answer:
(c) 25

Question 14.
One of the most resistant biological material present in the exine of pollen grain is
(a) pectocellulose
(b) sporopollenin
(c) suberin
(d) cellulose.
Answer:
(b) sporopollenin

Question 15.
What is the function of germ pore ?
(a) Emergence of radicle
(b) Absorption of water for seed germination
(c) Initiation of pollen tube
(d) All of these .
Answer:
(c) Initiation of pollen tube

Question 16.
_______of the pollen grain divides to form two male gametes.
(a) Vegetative cell
(b) Generative cell
(c) Microspore mother cell
(d) None of these
Answer:
(b) Generative cell

Question 17.
The three cells found in a pollen grain when it is shed at 3-celled stage are
(a) 1 vegetative cell, 1 generative cell, 1 male gamete
(b) 1 vegetative cell, 2 male gametes
(c) 1 generative cell, 2 male gametes
(d) either (a) or (b).
Answer:
(b) 1 vegetative cell, 2 male gametes

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 18.
Megasporangium along with its protective integuments is called
(a) ovary
(b) ovule
(c) funicle
(d) chalaza
Answer:
(b) ovule

Question 19.
Mature ovules are classified on the basis of funiculus. If micropyle comes to lie close to the funiculus the ovule is termed as
(a) orthotropous
(b) anatropous
(c) hemitropous
(d) campylotropous
Answer:
(b) anatropous

Question 20.
When micropyle, chalaza and hilum lie in a straight line, the ovule is said to be
(a) anatropous
(b) orthotropous
(c) amphitropous
(d) campylotropous.
Answer:
(b) orthotropous

Question 21.
What is the function of filiform apparatus in an angiospermic embryo sac?
(a) Brings about opening of the pollen tube
(b) Guides the pollen tube into a synergid
(c) Prevents entry of more than one pollen tube into a synergid
(d) None of these
Answer:
(b) Guides the pollen tube into a synergid

Question 22.
The female gametophyte of a typical dicot at the time of fertilisation is
(a) 8 – celled
(b) 7 – celled
(c) 6 – celled
(d) 5 – celled
Answer:
(b) 7 – celled

Question 23.
Polygonum type of embryo sac is
(a) 8 – nucleate, 7 – celled
(b) 8 – nucleate, 8 – celled
(c) 7 – nucleate, 7 – celled
(d) 4 – nucleate, 3 – celled
Answer:
(a) 8 – nucleate, 7 – celled

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 24.
Both chasmogamous and cleistogamous flowers are present in
(a) Helianthus
(b) Commelina
(c) Rosa
(d) Gossypium
Answer:
(b) Commelina

Question 25.
Even in absence of pollinating agents seed-setting is assured in
(a) Commelina
(b) Zostera
(c) Salvia
(d) Fig
Answer:
(a) Commelina

Question 26.
Male and female flowers are present on different plants (dioecious) to ensure xenogamy, in
(a) papaya
(b) bottle gourd
(c) maize
(d) all of these.
Answer:
(a) papaya

Question 27.
Feathery stigma occurs in
(a) pea
(b) wheat
(c) Datura
(d) Caesalpinia
Answer:
(b) wheat

Question 28.
Plants with ovaries having only one or a few ovules are generally pollinated by
(a) bees
(b) butterflies
(c) birds
(d) wind
Answer:
(d) wind

Question 29.
Which of the following is not a water pollinated plant ?
(a) Zostera
(b) Vallisneria
(c) Hydrilla
(d) Cannabis
Answer:
(d) Cannabis

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 30.
Spiny or sticky pollen grains and large, attractively coloured flowers are associated with
(a) hydrophily
(b) entomophily
(c) ornithophily
(d) anemophily
Answer:
(b) entomophily

Question 31.
Fragrant flowers with well developed nectaries are an adaptation for
(a) hydrophily
(b) anemophily
(c) entomophily
(d) none of these
Answer:
(c) entomophily

Question 32.
Pollen kitt is generally found in
(a) anemophilous flowers
(b) entomophilous flowers
(c) ornithophilous flowers
(d) malacophilous flowers
Answer:
(b) entomophilous flowers

Question 33.
Which of these is a condition that makes flowers invariably autogamous ?
(a) Dioecy
(b) Self incompatibility
(c) Cleistogamy
(d) Xenogamy
Answer:
(c) Cleistogamy

Question 34.
Heterostyly as a contrivance for cross-pollination is found in
(a) Pennisetum
(b) Impatiens
(c) Primula vulgaris
(d) Oenothera
Answer:
(c) Primula vulgaris

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 35.
The part of gynoecium that determines the compatible nature of pollen is
(a) stigma
(b) style
(c) ovary
(d) synergids
Answer:
(a) stigma

Question 36.
Part of the gynoecium which receives the pollen is called
(a) style
(b) stigma
(c) ovule
(d) ovary
Answer:
(b) stigma

Question 37.
Growth of pollen tube towards embryo sac is
(a) chemotropic
(b) thigmotaxis
(c) geotropic
(d) none of these
Answer:
(a) chemotropic

Question 38.
During the process of fertilisation the pollen tube of the pollen grain usually enters the embryo sac through
(a) integument
(b) nucellus
(c) chalaza
(d) micropyle
Answer:
(d) micropyle

Question 39.
Fusion of one of the male gametes with egg nucleus is referred to as
(a) generative fertilisation
(b) syngamy
(c) vegetative fertilisation
(d) both (a) and (b)
Answer:
(d) both (a) and (b)

Question 40.
The total number of nuclei involved in double fertilisation in angiospersm are
(a) two
(b) three
(c) four
(d) five
Answer:
(d) five

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 41.
Triple fusion in Capsella bursa pastoris is fusion of male gamete with
(a) egg
(b) synergid
(c) secondary nucleus
(d) antipodal.
Answer:
(c) secondary nucleus

Question 42.
Double fertilisation was first discovered in 1898 by _______ in Fritillaria and Lilium.
(a) Nawaschin
(b) Strasburger
(c) Amici
(d) Focke
Answer:
(a) Nawaschin

Question 43.
If an endosperm cell of an angiosperm contains 24 chromosomes, the number of chromosomes in each cell of the root will be
(a) 8
(b) 4
(c) 16
(d) 24
Answer:
(c) 16

Question 44.
The cells of endosperm have 24 chromosomes. What will be the number of chromosomes in the gametes ?
(a) 8
(b) 16
(c) 23
(d) 32
Answer:
(a) 8

Question 45.
The true embryo develops as a result to fusion of
(a) two polar nuclei of embryo sac
(b) egg cell and male gamete
(c) synergid and male gamete
(d) male gamete and antipodals.
Answer:
(b) egg cell and male gamete

Question 46.
Father of Indian embryology is
(a) P. Maheshwari
(b) Swaminathan
(c) R. Misra
(d) Butler
Answer:
(a) P. Maheshwari

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 47.
The portion of embryonal axis between plumule (future shoot) and cotyledons is called
(a) hypocotyl
(b) epicotyl
(c) coleorhiza
(d) coleoptile.
Answer:
(b) epicotyl

Question 48.
Coleoptile and coleorhiza are the protective sheaths _______ covering _______ and _______ respectively.
(a) plumule, epicotyl
(b) radicle, plumule
(c) plumule, radicle
(d) radicle, hypocotyl
Answer:
(c) plumule, radicle

Question 49.
_______ is not an endospermic seed.
(a) Pea
(b) Castor
(c) Maize
(d) Wheat
Answer:
(a) Pea

Question 50.
Endosperm is completely consumed by the developing embryo in
(a) pea and groundnut
(b) maize and castor
(c) castor and groundnut
(d) maize and pea.
Answer:
(a) pea and groundnut

Question 51.
Endospermic seeds are found in
(a) castor
(b) barley
(c) coconut
(d) all of these
Answer:
(d) all of these

Question 52.
In albuminous seeds, food is stored in _______ and in non albuminous seeds, it is stored in _______.
(a) endosperm, cotyledons
(b) cotyledons, endosperm
(c) nucellus, cotyledons
(d) endosperm, radicle
Answer:
(a) endosperm, cotyledons

Question 53.
Persistent nucellus is called as _______ and is found in _______.
(a) perisperm, black pepper
(b) perisperm, groundnut ‘
(c) endosperm, black pepper
(d) endosperm groundnut
Answer:
(a) perisperm, black pepper

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Question 54.
Indentify the wrong statement regarding post-fertilisation development.
(a) The ovary wall develops into pericarp.
(b) The outer integument of ovule develops into tegmen.
(c) The fusion nucleus (triple nucleus) develops into endosperm.
(d) The ovule develops into seed.
Answer:
(b) The outer integument of ovule develops into tegmen.

Question 55.
Polyembryony commonly occurs in
(a) banana
(b) tomato
(c) potato
(d) citrus.
Answer:
(d) citrus.

Question 56.
An embryo may sometimes develop from any cell of embryo sac other than egg. It is termed as
(a) apospory
(b) apogamy
(c) parthenogenesis
(d) parthenocarpy
Answer:
(b) apogamy

Question 57.
Embryo sac is to ovule as _______ is to an anther.
(a) Stamen
(b) filament
(c) pollen grain
(d) androecium
Answer:
(c) pollen grain

Question 58.
The outermost and innermost wall layers of microsporangium in an anther are respectively
(a) endothecium and tapetum
(b) epidermis and endodermis
(c) epidermis and middle layer
(d) epidermis and tapetum.
Answer:
(d) epidermis and tapetum.

Question 59.
During microsporogenesis, meiosis occurs in
(a) endothecium
(b) microspore mother cells
(c) microspore tetrads
(d) pollen grains
Answer:
(b) microspore mother cells

Question 60.
From among the sets of terms given below, identify those that are associated with the gynoecium.
(a) Stigma, ovule, embryo sac, placenta
(b) Thalamus, pistil, style, ovule
(c) Ovule, ovary, embryo sac, tapetum
(d) Ovule, stamen, ovary, embryo sac
Answer:
(a) Stigma, ovule, embryo sac, placenta

Question 61.
Starting from the innermost part, the correct sequence of parts in an ovule are
(a) egg, nucellus, embryo sac, integument
(b) egg, embryo sac, nucellus, integument
(c) embryo sac, nucellus, integument, egg
(d) egg. integument, embryo sac, nucellus.
Answer:
(b) egg, embryo sac, nucellus, integument

Question 62.
The phenomenon wherein, the ovary develops into a fruit without fertilisation is called
(a) parthenocarpy
(b) apomixis
(c) asexual reproduction
(d) sexual reproduction
Answer:
(a) parthenocarpy

Bihar Board 12th Biology Objective Answers Chapter 2 Sexual Reproduction in Flowering Plants

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Bihar Board 12th Chemistry Objective Questions and Answers

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 1.
When a chemical reaction takes place, during the course of the reaction the rate of reaction
(a) keeps on increasing with time
(b) remains constant with time
(c) keeps on decreasing with time
(d) shows irregular trend with time
Answer:
(c) keeps on decreasing with time

Question 2.
Consider the reaction :
\(2 \mathrm{N}_{2} \mathrm{O}_{4} \rightleftharpoons 4 \mathrm{N} \mathrm{O}_{2}\) \(\frac{\mathrm{d}\left[\mathrm{N}_{2} \mathrm{O}_{4}\right]}{\mathrm{dt}}=\mathrm{k} \text { and } \frac{\mathrm{d}\left[\mathrm{NO}_{2}\right]}{\mathrm{dt}}=k^{\prime}\) then
(a) 2k = k’
(b) k = 2k’
(c) k = k’
(d) k = 1/4 k’
Answer:
(b) k = 2k’
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 1

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 3.
For the reaction 2NH3 →N2 + 3H2, if –\(\frac{\mathrm{d}\left[\mathrm{NH}_{3}\right]}{\mathrm{dt}}=\mathrm{k}_{1}\left[\mathrm{NH}_{3}\right], \frac{\mathrm{d}\left[\mathrm{N}_{2}\right]}{\mathrm{dt}}\) then the relation between k1, k2 and k3 is ………….
(a) k1= k2 = &3
(b) k1 = 3 k2 = 2 k2
(c) 1.5k1 = 3k2 = k3
(d) 2k1= k2 = 3k3
Answer:
(c) 1.5k1 = 3k2 = k3

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 2

Question 4.
The rate of disappearance of SO2 in the reaction, 2SO2 + O2 → 2SO3 is 1.28 x 10-5 M s-1. The rate of appearance of SO3 is …………..
(a) 64 x 10-5 M s-1
(b) 0.32 x 10-5 M s-1
(c) 2.56 x 10-5 Ms-1
(d) 1.28 x 10-5 M s-1
Answer:
(d) 1.28 x 10-5 M s-1

Question 5.
In a reaction 2X → Y, the concentration of X decreases from 3.0 moles/litre to 2.0 moles/litre in 5 minutes. The rate of reaction is ………………..
(a) 1 mol L-1 min-1
(b) 5 mol L-1 min-1
(c) 1 mol L-1 min-1
(d) 0.5 mol L-1 min-1
Answer:
(a) 1 mol L-1 min-1

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 3
Negative sign signifies the decrease in concentration

Question 6.
The rate constant of a reaction depends upon
(a) temperature of the reaction
(b) extent of the reaction
(c) initial concentration of the reaction
(d) the time of completion of reaction
Answer:
(a) temperature of the reaction

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 7.
The chemical reaction, 2O3 → 3O2 proceeds as
\(\mathbf{O}_{3} \rightleftharpoons \mathbf{O}_{2}+[\mathbf{O}] \text { (fast) }\) [O] + O3 → 2O2 (slow) The rate law expression will be ………….
(a) Rate = k[O] [O3]
(b) Rate = k[O3]2 [O2]-1
(c) Rate = it [O3]2
(d) Rate = k [O2] [O]
Answer:
(b) Rate = k[O3]2 [O2]-1

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 4
[O] is unstable intermediate so substitute the value of
[O] in above equation.
Rate of forward reaction = k1 [O3]
Rate of backward reaction = [k-1] [O2] [O]
At equilibrium,
Rate of forward reaction = Rate of backward reaction

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 5

Question 8.
Rate constant in case of first order reaction is
(a) inversely proportional to the concentration units
(b) independent of concentration units
(c) directly proportional to concentration units
(d) inversely proportional to the square of concentration units
Answer:
(b) independent of concentration units

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 9.
The rate constant for the reaction, 2N2Os → 4NO2 + O2 is 2 x 105s-1. If rate of reaction is 1.4 x 10-5 mol L-1 s-1, what will be the concentration of N2O5 in mol L-1?
(a) 8
(b) 0.7
(c) 1.2
(d) 1
Answer:
(b) 0.7
(b) Rate = k[N2O5] (first order as unit of rate constant is s-1)
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 6
Question 10.
The order of reaction is decided by…………..
(a) temperature
(b) mechanism of reaction as well as relative concentration of reactants
(c) molecularity
(d) pressure
Answer:
(b) mechanism of reaction as well as relative concentration of reactants

Question 11.
Which of the following is an example of a fraction order reaction ?
(a) NH4NO2 → N2 +2H2O
(b) NO + O3 → NO2+O2
(c) 2NO + Br2 → 2NOBr
(d) CH3CHO → CH4 + CO
Answer:
(d) CH3CHO → CH4 + CO

Question 12.
What will be the rate equation for the reaction 2X + Y→ Z, if the order of the reaction is zero ?
(a) Rate = k[X] [Y]
(b) Rate = k
(c) Rate = A[X]0[Y]
(d) Rate = k[X][Y]0
Answer:
(b) Rate = k

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 13.
For a reaction, I+ OCl → IO + Cl in an aqueous medium, the rate of reaction is given by \(\frac{\mathrm{d}\left[\mathrm{I} \mathrm{O}^{-}\right]}{\mathrm{dt}}=\mathrm{k} \frac{\left[\mathrm{I}^{-}\right]\left[\mathrm{OCl}^{-}\right]}{\left[\mathrm{OH}^{-}\right]}\) is
(a) – 1
(b) 0
(c) 1
(d) 2
Answer:
(c) 1

Question 14.
The unit of rate constant for the reaction, 2H2 + 2NO → 2H2O + N2 which has rate – k[H2][NO]2, is …………..
(a) molL1s-1
(b) s-1
(c) mol1L2s-1
(d) mol L-1
Answer:
(c) mol1L2s-1

(c) Unit of rate constant for the reaction is
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 7
Question 15.
The unit of rate and rate constant are same for a…………….
(a) zero order reaction
(b) first order reaction
(c) second order reaction
(d) third order reaction
Answer:
(a) zero order reaction

Question 16.
The number of molecules of the reactants taking part in a single step of the reaction is indicative of
(a) order of a reaction
(b) molecularity of a reaction
(c) fast step of the mechanism of a reaction
(d) half-life of the reaction
Answer:
(b) molecularity of a reaction

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 17.
The overall rate of a reaction is governed by
(a) the rate of fastest intermediate step
(b) the sum of the rates of all intermediate steps
(c) the average of the rates of all the intermediate steps
(d) the rate of slowest intermediate step.
Answer:
(d) the rate of slowest intermediate step.

Question 18.
The expression to calculate time required for completion of zero order reaction is ………..
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 8
Answer:
(a)

Question 19.
A plot, of log (a -x) against time t is a striaght line. This indicates that the reaction is of
(a) zero order
(b) first order
(c) second order
(d) third order
Answer:
(b) first order

Question 20.
Radioactive disintegration is an example of ……………
(a) zero order reaction
(b) first order reaction
(c) second order reaction
(d) third order reaction
Answer:
(b) first order reaction

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 21.
The rate constant of a first order reaction is 15 x 10-3 s-1. How long will 5.0 g of this reactant take to reduce to 3.0 g ?
(a) 07 s
(b) 7.57 s
(c) 10.10 s
(d) 15 s
Answer:
(a) 07 s
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 9

Question 22.
A first order reaction is 20% complete in 10 minutes. What is the specific rate constant for the reaction ?
(a) 0970 min-1
(b) 0.009 min-1
(c) 0.0223 min-1
(d) 2.223 min-1
Answer:
(c) 0.0223 min-1

Question 23.
A first order reaction takes 40 min for 30% decomposition. What will be t1/2 ?
(a) 7 min
(b) 52.5 min
(c) 46.2 min
(d) 22.7 min
Answer:
(a) 7 min
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 10

Question 24.
A first order reaction has a rate constant 1.15 x 10-3 s-1. How long will 5 g of this reaction take to reduce to 3 g ?
(a) 444 s
(b) 400 s
(c) 528 s
(d) 669 s
Answer:
(a) 444 s

Question 25.
Half-life period of a first order reaction is 10 min. What percentage of the reaction will be completed in 100 min ?
(a) 25%
(b) 50%
(c) 99.9%
(d) 75%
Answer:
(c) 99.9%

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 26.
The rate constant for a first order reaction is 2 x 10-2 min-1. The half-life period of reaction is
(a) 69.3 min
(b) 34.65 min
(c) 17.37 min
(d) 3.46 min
Answer:
(b) 34.65 min

Question 27.
The value of rate of a pseudo first order reaction depends upon
(a) the concentration of both the reactants present in the reaction
(b) the concentration of the reactant present in small amount
(c) the concentration of the reactant present in excess
(d) the value of ΔH of the reaction
Answer:
(b) the concentration of the reactant present in small amount

Question 28.
Under what conditions a bi-molecular reaction may be kinetically of first order ?
(a) When both reactants have same concentration
(b) When one of the reacting species is in large excess
(c) When the reaction is at equilibrium
(d) When the activation energy of reaction is less
Answer:
(b) When one of the reacting species is in large excess

Question 29.
The hydrolysis of ethyl acetate, ……………….
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 11
(a) zero order
(b) pseudo first order
(c) second order
(d) third order
Answer:
(b) pseudo first order

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 30.
The temperature dependence of the rate of a chemical reaction can be explained by Arrhenius equation which is…..
(a) k = AeEa/RT
(b) k = Ae-Ea/RT
(c) K = Ae x \(\frac{\mathrm{E}_{\mathrm{a}}}{\mathrm{RT}}\)
(d) K = Ae x \(\frac{R T}{E_{a}}\)
Answer:
(a) k = AeEa/RT

Question 31.
The energy diagram of a reaction P + Q → R + Sis given. What are A and B in the graph ?
Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 12
(a) A → activation energy, B → heat of reaction
(b) A → threshold energy, B →heat of reaction
(c) A → heat of reaction, B → activation energy
(d) A →potential energy, B → energy of reaction
Answer:
(a) A → activation energy, B → heat of reaction

Question 32.
For an endothermic reaction, AH represents the enthalpy of the reaction in kj mol-1. The minimum amount of activation energy will be
(a) less than zero
(b) equal to ΔH
(c) less than ΔH
(d) more than ΔH
Answer:
(d) more than ΔH

Question 33.
The decomposition of a hydrocarbon follows the equation k = (4.5 x 1011 s-1) e-28000 K/T. What will be the value of activation energy ?
(a) 669 kJ mol-1
(b) 232.79   kJ mol-1
(c) 4.5 x 10-1 kJ mol-1
(d) 28000 kJ mol-1
Answer:
(b) 232.79   kJ mol-1

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

(b) Arrhenius equation, k = Ae Ea/RT
Given equation is k = (4.5x 1011 s-1)e-28000 K/T
Comparing both the equations, we get
\(=\frac{E_{a}}{R T}=-\frac{28000 K}{T}\)
Ea = 28000 K x R = 280000 K x 8.314JK-1mol-1
= 232.79 kJ mol-1

Question 34.
The rate constant for a first order reaction at 300°C for which Ea is 35 kcal mol-1 and frequency constant is 1.45 x 1011 s-1 is
(a) 10 x 10-2s-1
(b) 5.37 x 1010s-1
(c) 5 x 10-4s-1
(d) 7.94 x 10-3s-1
Answer:
(d) 7.94 x 10-3s-1

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics 13

Question 35.
The increase in concentration of the reactants lead to change in
(a) ΔH
(b) collision frequency
(c) activation energy
(d) equilibrium constant
Answer:
(b) collision frequency

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 36.
The rate constant is given by the equation k = P.Ze-Ea/RT  Which factor should register a decrease for the reaction to proceed more rapidly ?
(a) T
(b) Z
(c) E
(d) P
Answer:
(c) E

Question  37.
Threshold energy is equal to ……………
(a) activation energy
(b) activation energy – energy of molecules
(c) activation energy + energy of molecules
(d) None of these
Answer:
(c) activation energy + energy of molecules

Question 38.
The role of a catalyst is to change………………..
(a) Gibbs energy of reaction
(b) enthalpy of reaction
(c) activation energy of reaction
(d) equilibrium constant
Answer:
(c) activation energy of reaction

Question 39
In the presence of a catalyst, the heat evolved or absorbed during the reaction…………..
(a) increases
(b) decreases
(c) remains unchanged
(d) may increase or decrease
Answer:
(c) remains unchanged

Bihar Board 12th Chemistry Objective Answers Chapter 4 Chemical Kinetics

Question 40.
A first order reaction is 50% completed in 1.26 x 1014 How much time would it take for 100% completion ?
(a) 1.26 x 1015 s
(b) 2.52 x 1014 s
(c) 2.52 x 1028 s
(d) Infinite
Answer:
(d) Infinite

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Bihar Board 12th Physics Objective Questions and Answers

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 1.
At absolute zero, Si acts as a
(a) metal
(b) Semiconductor
(c) insulator
(d) None of these
Answer:
(c) insulator

Question 2.
In good conductors of electricity the type of bonding that exist is
(a) van der Walls
(b) covalent
(c) ionic
(d) metallic
Answer:
(d) metallic

Question 3.
The manifestation of band structure in solids is due to
(a) Heisenberg uncertainty principle
(b) Pauli’s exclusion principle
(c) Bohr’s correspondence principle
(d) Boltzmann law
Answer:
(b) Pauli’s exclusion principle

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 4.
The probability of electrons to be found in the conduction band of an intrinsic semicondutor of finite temperature
(a) increases exponentially with increasing band gap
(b) decreases exponentially with increasing band gap
(c) decreases with increasing temperature
(d) is independent of the temperature and band gap
Answer:
(b) decreases exponentially with increasing band gap

Question 5.
In n-type semiconductor when all donor states are filled, then the net charge density in the donor states becomes
(a) 1
(b) > 1
(c) < 1, but not zero
(d) zero
Answer:
(b) > 1

Question 6.
A semiconductor has equal electron and hole concentration of 6 x 108 per m3. On doping with certain impurity, electron concentration increases to 9 x 1012 per m3. The new hole concentration is
(a) 2 x 104 per m3
(b) 2 x 102 per m3
(c) 4 x 104 per m3
(d) 4x 102 perm3
Answer:
(c) 4 x 104 per m3

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 7.
The dominant mechanism for motion of charge carriers in forward and reverse biased silicon p-n junction are
(a) drift in forward bias, diffusion in reverse bias
(b) diffusion in forward bias, drifit in reverse bias
(c) diffusion in both forward and reverse bias
(d) drift in both forward and reverse bias
Answer:
(b) diffusion in forward bias, drifit in reverse bias

Question 8.
Region without free electrons and holes in a p-n junction is
(a) n-region
(b) p-region
(c) depletion region
(d) none of these
Answer:
(c) depletion region

Question 9.
Potential barrier developed in a junction diode opposes the flow of
(a) minority carrier in both regions only
(b) majority carriers only
(c) electrons in p region
(d) holes in p region
Answer:
(b) majority carriers only

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 10.
A potential barrier of 0.3 V exists across a p-n junction. If the depletion region is 1 pm wide, what is the intensity of electric field in this region ?
(a) 2 x 105 V m-1
(b) 3 x 105 V m-1
(c) 4 x 105 V m-1
(d) 5 x 105 V m-1
Answer:
(b) 3 x 105 V m-1

Question 11.
A forward-biased diode is
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits1
Answer:
(a)

Question 12.
When the voltage drop across a p-n junction diode is increased from 0.65 V to 0.70 V, the change in the diode current is 5 mA. The dynamic resistance of the diode is
(a) 5 Ω
(b) 10 Ω
(c) 20 Ω
(d) 25 Ω
Answer:
(b) 10 Ω

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 13.
In the circuit shown if current for the diode is 20 pA, the potential difference across the diode is
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits2
(a) 2 V
(b) 4.5 V
(c) 4 V
(d) 2.5 V
Answer:
(c) 4 V

Question 14.
The equivalent resistance of the circuit shown in figure between the points A and B if VA < VB is
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits3
(a) 10 Ω
(b) 20 Ω
(c) 5 Ω
(d) 40 Ω
Answer:
(b) 20 Ω

Question 15.
In the question number 34, the equivalent resistance between the points A and B, if VA > VB is
(a) 10 Ω
(b) 20 Ω
(c) 30 Ω
(d) 15 Ω
Answer:
(a) 10 Ω

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 16.
In a half wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be
(a) 25 Hz
(b) 50 Hz
(c) 70.7 Hz
(d) 100 Hz
Answer:
(b) 50 Hz

Question 17.
What happens during regulation action of a Zener diode?
(a) The current through the series resistance (RS) changes
(b) The resistance offered by the Zener changes
(c) The Zener resistance is constant
(d) Both (a) and (b)
Answer:
(d) Both (a) and (b)

Question 18.
From the Zener diode circuit shown in figure, the current through the Zener diode is
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits4
(a) 34 mA
(b) 31.5 mA
(c) 36.5 mA
(d) 2.5 mA
Answer:
(b) 31.5 mA

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 19.
A p-n photodiode is fabricated from a semiconductor with a band gap of 2.5 eV. The signal wavelength is
(a) 6000 A
(b) 6000 nm
(c) 4000 nm
(d) 5000 A
Answer:
(d) 5000 A

Question 20.
The transfer characteristics of a base biased transistor has the operation regions, namely, cutoff, active region and saturation region. For using the transistor as an amplifier it has to operate in the
(a) active region
(b) cutoff region
(c) saturation region
(d) cutoff and saturation
Answer:
(a) active region

Question 21.
The emitter of transistor is doped the heaviest because it
(a) acts as a supplier of charge carriers
(b) dissipates maximum power
(c) has a larger resistance
(d) has a small resistance
Answer:
(a) acts as a supplier of charge carriers

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 22.
The heavily and lightly doped regions of a bipolar junction transistor are respectively
(a) base and emitter
(b) base and collector
(c) emitter and base
(d) collector and emitter
Answer:
(c) emitter and base

Question 23.
An oscillator is nothing but an amplifier with
(a) larger gain
(b) positive feedback
(c) no feedback
(d) negative feedback
Answer:
(b) positive feedback

Question 24.
The current amplification factor a of a common base transistor and the current amplification factor 3 of a common emitter transistor are not related by
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits5
Answer:
(d)

Question 25.
If a and 3 are the current gain in the CB and CE configurations respectively of the transistor circuit, then \(\frac{\beta-\alpha}{\alpha \beta}=\)
(a) zero
(b) 1
(c) 2
(d) 0.5
Answer:
(b) 1

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 26.
A transistor connected in common emitter mode, the voltage drop across the collector is 2 V and 3 is 50, the base current if Rc is 2 kΩ is
(a) 40 μA
(b) 20 μA
(c) 30 μA
(d) 15 μA
Answer:
(b) 20 μA

Question 27.
The current gain for a common emitter amplifier is 69. If the emitter current is 7 mA, the base current is
(a) 0.1 m A
(b) 1 mA
(c) 0.2 m A
(d) 2 mA
Answer:
(a) 0.1 m A

Question 28.
The ac current gain of a transistor is 120. What is the change in the collector current in the transistor whose base current changes by 100 μA ?
(a) 6 mA
(b) 12 mA
(c) 3 mA
(d) 24 mA
Answer:
(b) 12 mA

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 29.
In an n-p-n circuit transistor, the collector current is 10 mA. If 80% electron emitted reach the collector, then
(a) the emitter current will be 7.5 mA
(b) the emitter current will be 12.5 mA
(c) the base current will be 3.5 mA
(d) the base current will be 1.5 mA
Answer:
(b) the emitter current will be 12.5 mA

Question 30.
A transistor has a current gain of 30. If the collector resistance is 6 kΩ, input resistance is 1 kΩ, it voltage gain is
(a) 90
(b) 180
(c) 45
(d) 360
Answer:
(b) 180

Question 31.
In a transistor connected in common emitter mode, Rc =4 kΩ, R1 = 1 kΩ, Ic = 1 mA and IB = 20μA. The voltage gain is
(a) 100
(b) 200
(c) 300
(d) 400
Answer:
(b) 200

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 32.
In an n-p-n transistor 1010 electron enter the emitter in 10-6 s. If 2% of the electrons are lost in the base, the current amplification factor is
(a) 0.02
(b) 7
(c) 33
(d) 4.9
Answer:
(a) 0.02

Question 33.
If a change of 100 pA in the base current of an n-p-n transistor causes a change of 10 mA in its collector current, its ac current gain is
(a) 50
(b) 100
(c) 200
(d) 150
Answer:
(b) 100

Question 34.
What is the voltage gain in a common emitter amplifier, where input resistance is 3Ω and load resistance 24 Ω and β = 61 ?
(a) 8.4
(b) 488
(c) 240
(d) 0
Answer:
(b) 488

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 35.
An amplifier has a voltage gain of 100. The voltage gain in dB is
(a) 20 dB
(b) 40 dB
(c) 30dB
(d) 50dB
Answer:
(b) 40 dB

Question 36.
Boolean algebra is essentially based on
(a) number
(b) truth
(c) logic
(d) symbol
Answer:
(c) logic

Question 37.
The symbolic representation of four logic gates are given below. The logic symbols for OR, NOT and NAND gates are respectively.
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits6
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits7
(a) (i v), (i), (ii i)
(b) (i v), (ii), (i)
(c) (i), (iii), (iv)
(d) (iii), (iv), (ii).
Answer:
(b) (i v), (ii), (i)

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 38.
Study the circuit shown in the figure. Name the gate that the given circuit resembles.
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits8
(a) NAND
(b) AND
(c) OR
(d) NOR
Answer:
(b) AND

Question 39.
In Boolean algebra if A = 1 and B = 0, then the value of A + \(\bar{B}\) is
(a) A
(b) A.B
(c) A + B
(d) both (a) and (c)
Answer:
(d) both (a) and (c)

Question 40.
What will be input of A and B for the Boolean expression \((\overline{A+B}) \cdot(\overline{A \cdot B})=1 ?\)?
(a) (0, 0)
(b) (0, 1)
(c) (1, 0)
(d) (1, 1)
Answer:
(a) (0, 0)

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 41.
The circuit given in figure, is equivalent to
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits9
(a) AND gate
(b) OR gate
(c) NOT gate
(d) NAND gate
Answer:
(a) AND gate

Question 42.
The given truth table is for which logic gate ?
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits10
(a) NAND
(b) XOR
(c) NOR
(d) OR
Answer:
(a) NAND

Question 43.
The decimal equivalent of the binary number (11010.101) 2is
(a) 9.625
(b) 25.265
(c) 26.625
(d) 26.265
Answer:
(d) 26.265

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 44.
Hole is
(a) an anti-particle of electron.
(b) a vacancy created when an electron leaves a covalent bond.
(c) absence of free electrons.
(d) an artificially created particle.
Answer:
(b) a vacancy created when an electron leaves a covalent bond.

Question 45.
In the circuit shown in figure, if the diode forward voltage drop is 0.3 V, the voltage difference between A and B is
(a) 1.3 V
(b) 2.3 V
(c) 0
(d) 0.5V
Answer:
(b) 2.3 V

Hints & Explanations

Question 6.
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits11

Question 12.
(b) Dynamic resistance is \(r_{d}=\frac{\Delta V}{\Delta I}\)
Answer:
Here, ΔV = 0.7 – 0.65 V = 0.05 V,
ΔI = 5 mA = 5 x 10-3 A
∴ \(r_{d}=\frac{0.05}{5 \times 10^{-3}}=10 \Omega\)

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 13.
(c) Since the diode is reversed biased, only drift current exists in circuit which is 20 pA.
Answer:
Potential drop across 15 Ω resistor
= 15 Ω x 20 μA
= 300 μV = 0.0003 V
Potential difference across the diode
= 4 – 0.0003
= 3.99 = 4V

Question 14.
(b) When VA < VB, the diode gets reverse biased and offers infinite resistance. No current flows through the upper branch
∴ R = 20 Ω

Question 18.
(b) Here, RL = 5 x 103 Ω, V, = 220 V,
Zener voltage, VZ = 50 V
Answer:
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits12

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 19.
(d) The detection occurs only when the energy of incident photon greater than or equal to the energy band gap
Answer:
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits13

Question 25.
(b) Since P = \(\beta=\frac{\alpha}{1-\alpha}\)
Answer:
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits14

Question 26.
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits15

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 27.
(a) Current gain, \(\beta=\frac{I_{C}}{I_{B}}\)
Answer:
For common emitter configuration, IE = Ic
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits16

Question 28.
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits17

Question 29.
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits 18

Question 30.
(b) Voltage gain = current gain x resistance gain
= current gain \(\times \frac{R_{C}}{R_{I}}=30 \times \frac{6}{1}=180\)

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Question 31.
(b) Voltage gain,
Answer:
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits19

Question 32.
(a) As, \(I_{E}=\frac{n_{E} \times e}{t}\)
Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits - 20

Question 33.
(b) Here, \(\Delta I_{B}=100 \mu \mathrm{A}=100 \times 10^{-6} \mathrm{A}\) Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics Materials, Devices and Simple Circuits - 21 (2)

Question 34.
(b) Voltage gain, \(A_{V}=\beta \frac{R_{o}}{R_{i}}=\frac{61 \times 24}{3}=488\)

Bihar Board 12th Physics Objective Answers Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Bihar Board 12th Biology Objective Questions and Answers

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 1.
The colour based contrasting traits in seven contrasting pairs, studied by Mendel in pea plant were
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(c) 3

Question 2.
_________ pairs of contrasting traits were studied by Mendel in pea plant.
(a) 6
(b) 7
(c) 8
(d) 10
Answer:
(b) 7

Question 3.
Which of the following characters was not chosen by Mendel ?
(a) Pod shape
(b) Pod colour
(c) Location of flower
(d) Location of pod
Answer:
(d) Location of pod

Question 4.
Genes which code for a pair of contrasting traits are known as
(a) dominant genes
(b) alleles
(c) linked genes
(d) none of these
Answer:
(b) alleles

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 5.
A recessive allele is expressed in
(a) heterozygous condition only
(b) homozygous condition only
(c) F3 generation
(d) both homozygous and heterozygous conditions.
Answer:
(b) homozygous condition only

Question 6.
The characters which appear in the first filial generation are called
(a) recessive characters
(b) dominant characters
(c) holandric characters
(d) lethal characters
Answer:
(b) dominant characters

Question 7.
What will be the distribution of phenotypic features in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus ?
(a) 3 : 1
(b) 1 : 2 : 1
(c) 1 : 1
(d) None of these
Answer:
(c) 1 : 1

Question 8.
In a monohybrid cross between two heterozygous individuals, percentage of pure homozygous individuals obtained in F1 generation will be
(a) 25 %
(b) 50 %
(c) 75 %
(d) 100 %
Answer:
(b) 50 %

Question 9.
What is the probability of production of dwarf offsprings in a cross betweeen two heterozygous tall pea plants ?
(a) Zero
(b) 50 %
(c) 25 %
(d) 100 %
Answer:
(c) 25 %

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 10.
Which of the following crosses will give tall and dwarf pea plants in same proportions ?
(a) TT × tt
(b) Tt × tt
(c) TT × Tt
(d) tt × tt
Answer:
(b) Tt × tt

Question 11.
To determine the genotype of a tall plant of F2 generation, Mendel crossed this plant with a dwarf plant. This cross represents a
(a) test cross
(b) back cross
(c) reciprocal cross
(d) dihybrid cross.
Answer:
(a) test cross

Question 12.
Which of the following is a test cross ?
(a) TT × TT
(b) Tt × Tt
(c) tt × tt
(d) Tt × tt
Answer:
(d) Tt × tt

Question 13.
Mendal formulated the law of purity of gametes on the basis of
(a) monohybrid cross
(b) dihybrid cross
(c) test cross
(d) back cross.
Answer:
(a) monohybrid cross

Question 14.
The inheritance of flower colour in Antirrhinum (dog flower) is an example of
(a) incomplete dominance
(b) co-dominance
(c) multiple alleles
(d) linkage.
Answer:
(a) incomplete dominance

Question 15.
In Antirrhinum (dog flower), phenotypic ratio in F2 generation for the inheritance of flower colour would be
(a) 3 : 1
(b) 1 : 2 : 1
(c) 1 : 1
(d) 2 : 1
Answer:
(b) 1 : 2 : 1

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 16.
Phenotypic and genotypic ratio is similar in case of
(a) complete dominance
(b) incomplete dominance
(c) over dominance
(d) epistasis.
Answer:
(b) incomplete dominancec

Question 17.
What can be the blood group of offspring when both parents have AB blood group ?
(a) AB only
(b) A, B and AB
(c) A, B, AB and O
(d) A and B only
Answer:
(b) A, B and AB

Question 18.
Inheritance of roan coat in cattle is an example of
(a) incomplete dominance
(b) codominance
(c) multiple allelism
(d) none of these
Answer:
(b) codominance

Question 19.
ABO blood grouping in human beings cites the example of
(a) incomplete dominance
(b) co-dominance
(c) multiple allelism
(d) both
(b) and (c)
Answer:
(b) and (c)

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 20.
In mice, Y is the dominant allele for yellow fur an y is the recessive allele for grey fur. Since Y is lethal when homozygous, the result of cross Yy × Yy will be
(a) 3 yellow : 1 grey
(b) 2 yellow : 1 grey
(c) 1 yellow : 1 grey
(d) 1 yellow : 2 grey
Answer:
(b) 2 yellow : 1 grey

Question 21.
In Mendelian dihybrid cross, when heterozygous Round Yellow are self crossed, Round Green offsprings are represented by the genotype
(a) RrYy, RrYY, RRYy
(b) Rryy, RRyy, rryy
(c) rrYy, rrYY
(d) Rryy, RRyy
Answer:
(d) Rryy, RRyy

Question 22.
The percentage of ab gamete produced by AaBb parent will be
(a) 25 %
(b) 50 %
(c) 75 %
(d) 12.5 %
Answer:
(a) 25 %

Question 23.
How many types of gametes can be produced by a diploid organism who is heterozygous for 4 loci ?
(a) 4
(b) 8
(c) 16
(d) 32
Answer:
(c) 16

Question 24.
Which of the following is correct for the condition when plant YyRr is back crossed with the double recessive parent ?
(a) 9 : 3 : 3 : 1 ratio of phenotypes only
(b) 9 : 3 : 3 : 1 ratio of genotypes only
(c) 1 : 1 : 1 : 1 ratio of phenotypes only
(d) 1 : 1 : 1 : 1 ratio of phenotypes and genotypes
Answer:
(d) 1 : 1 : 1 : 1 ratio of phenotypes and genotypes

Question 25.
Law of independent assortment can be explained with the help of
(a) dihybrid
(b) test cross
(c) back cross
(d) monohybrid cross
Answer:
(a) dihybrid

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 26.
Mendel’s work was rediscovered by three scientists in the year
(a) 1865
(b) 1900
(c) 1910
(d) 1920
Answer:
(b) 1900

Question 27.
Which three scientists independently rediscovered Mendel’s work ?
(a) Avery, McLeod, McCarty
(b) Sutton, Morgan and Bridges
(c) Bateson, Punnet and Bridges
(d) de Vries, Correns and Tschemark
Answer:
(d) de Vries, Correns and Tschemark

Question 28.
Chromosomal theory of inheritance was given by
(a) Morgan et al
(b) Sutton and Boveri
(c) Hugo deVries
(d) Gregor J. Mendel
Answer:
(b) Sutton and Boveri

Question 29
Experimental verification of ‘chromosomal theory of inheritance’ was done by
(a) Sutton and Boveri
(b) Morgan et al
(c) Henking
(d) Karl Correns.
Answer:
(b) Morgan et al

Question 30.
Genes located very close to one another on same chromosome tend to be transmitted together and are called as
(a) allelomorphs
(b) identical genes
(c) linked genes
(d) recessive genes
Answer:
(c) linked genes

Question 31.
What is true about the crossing over between linked genes ?
(a) No crossing over at all
(b) High percentage of crossing over
(c) Hardly any crossing over
(d) None of these
Answer:
(c) Hardly any crossing over

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 32.
Chromosome maps/genetic maps were first prepared by
(a) Sutton and Boveri (1902)
(b) Bateson and Punnett (1906)
(c) Morgan (1910)
(d) Sturtevant (1911)
Answer:
(d) Sturtevant (1911)

Question 33.
The distance between the genes is measured by
(a) angstrom
(b) map unit
(c) Dobson unit
(d) millimetre
Answer:
(c) Dobson unit

Question 34.
Which of the following is suitable for experiment on linkage ?
(a) aaBB x aaBB
(b) AABB x aabb
(c) AaBb x AaBb
(d) AAbb x AaBB
Answer:
(b) AABB x aabb

Question 35.
Mendel’s law of independent assortment does not hold true for the genes that are located closely on
(a) same chromosome
(b) non-homologous chromosomes
(c) X-chromosome
(d) autosomes
Answer:
(a) same chromosome

Question 36.
If linkage was known at the time of Mendel then which of the following laws, he would not have been able to explain ?
(a) Law of dominance
(b) Law of independent assortment
(c) Law of segregation
(d) Law of purity of gametes
Answer:
(b) Law of independent assortment

Question 37.
Which of the following are reasons for Mendel’s success ?
(i) Usage of pure lines or pure breeding varieties
(ii) Consideration of one character at a time
(iii) Maintenance of statistical records of experiments
(iv) Knowledge of linkage and incomplete dominance
(a) (i) and (ii) only
(b) (i), (ii) and (iii)
(c) (i) and (iv) only
(d) (ii), (iii) and (iv)
Answer:
(b) (i), (ii) and (iii)

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 38.
XO type of sex determination and XY type of sex determination are the examples of
(a) male heterogamety
(b) female heterogamety
(c) male homogamety
(d) both (b) and (c)
Answer:
(a) male heterogamety

Question 39.
Grasshopper is an example of XO type of sex determination in which the males have
(a) one X chromosome
(b) one Y chromosome
(c) two X chromosomes
(d) no X chromosome
Answer:
(a) one X chromosome

Question 40.
In XO type of sex determination
(a) females produce two different types of gametes
(b) males produce two different types of gametes
(c) females produce gametes with Y chromosome
(d) males produce gametes with Y chromosome.
Answer:
(b) males produce two different types of gametes

Question 41.
Which of the following is incorrect regarding ZW – ZZ type of sex determination ?
(a) It occurs in birds and some reptiles.
(b) Females are homogametic and males are heterogametic.
(c) 1:1 sex ratio is produced in the offsprings.
(d) All of these
Answer:
(b) Females are homogametic and males are heterogametic.

Question 42.
A couple has six daughters. What is the possibility of their having a girl next time ?
(a) 10 %
(b) 50 %
(c) 90 %
(d) 100 %
Answer:
(b) 50 %

Question 43.
Number of autosomes present in liver cells of a human female is
(a) 22 autosomes
(b) 22 pairs
(c) 23 autosomes
(d) 23 pairs
Answer:
(b) 22 pairs

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 44.
Haplodiploidy is found in
(a) grasshoppers and cockroaches
(b) birds and reptiles
(c) butterflies and moths
(d) honeybees, ants and waspe.
Answer:
(d) honeybees, ants and waspe.

Question 45.
Rate of mutation is affected by
(a) temperature
(b) X-rays
(c) gamma rays
(d) all of these.
Answer:
(d) all of these.

Question 46.
Two or more independent genes present on different chromosomes which determine nearly same phenotype are called
(a) supplementary genes
(b) complementary genes
(c) duplicate genes
(d) none of these.
Answer:
(c) duplicate genes

Question 47.
Select the incorrect statement regarding pedigree analysis.
(a) Solid symbols show unaffected individuals.
(b) Proband is the person from which case history starts.
(c) It is useful for genetic counsellors.
(d) It is an analysis of traits in several generations of a family.
Answer:
(a) Solid symbols show unaffected individuals.

Question 48.
Which one is the incorrect match ?
Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation 1
Answer:
Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation 2

Question 49.
________ is an example of X-linked recessive trait.
(a) Phenylketonuria
(b) Haemophilia
(c) Cystic fibrosis
(d) Sickle-cell anaemia
Answer:
(b) Haemophilia

Question 50.
Result of a cross between a normal homozygous female and a haemophiliac male would be
(a) normal males and normal females
(b) haemophilic males and normal females
(c) normal males and carrier females
(d) haemophilic males and carrier females.
Answer:
(c) normal males and carrier females

Question 51.
Father of a child is colourblind and mother is carrier for colourblindness, the probability of the child being colour blind is
(a) 25 %
(b) 50 %
(c) 100 %
(d) 75 %
Answer:
(b) 50 %

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 52.
A marriage between a colourblind man and a normal woman produces
(a) all carrier daughters and normal sons
(b) 50% carrier daughters, 50% normal daughters
(c) 50% colourblind sons, 50% normal sons
(d) all carrier offsprings.
Answer:
(a) all carrier daughters and normal sons

Question 53.
Which of the following is not an example of recessive autosomal disease ?
(a) Haemophilia
(b) Cystic fibrosis
(c) Phenylketonuria
(d) Sickle-cell anaemia
Answer:
(a) Haemophilia

Question 54.
If both parents are carriers for thalassaemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child ?
(a) 25 %
(b) 100 %
(c) No chance
(d) 50 %
Answer:
(a) 25 %

Question 55.
Select the disease which is caused by recessive autosomal genes when present in homozygous conditions.
(a) Alkaptonuria
(b) Albinism
(c) Cystic fibrosis
(d) All of these
Answer:
(d) All of these

Question 56.
Which of the following trait is controlled by dominant autosomal genes ?
(a) Polydactyly
(b) Huntington’s chorea
(c) PTC (phenylthiocarbamide) tasting
(d) All of these
Answer:
(d) All of these

Question 57.
Failure of segregation of chromatids during cell division results in the gain or loss of chromosomes, this is called as
(a) euploidy
(b) monoploidy
(c) aneuploidy
(d) polyploidy
Answer:
(c) aneuploidy

Question 58.
Trisomy is represented by
(a) (2n – 1)
(b) (2n – 2)
(c) (2n + 2)
(d) (2n + 1)
Answer:
(d) (2n + 1)

Question 59.
Mongolism is a genetic disorder which is caused by the presence of an extra chromosome number
(a) 20
(b) 21
(c) 17
(d) 23
Answer:
(b) 21

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 60.
Klinefelter’s syndrome is characterised by a karyotype of
(a) XYY
(b) XO
(c) XXX
(d) XXY
Answer:
(d) XXY

Question 61.
This abnormality occurs due to monosomy (2n – 1); the individual has 2n = 45 chromosomes with 44 + XO genotype.
(a) Edward’s syndrome
(b) Down’s syndrome
(c) Turner’s syndrome
(d) Klinefelter’s syndrome
Answer:
(c) Turner’s syndrome

Question 62.
Females with Turner’s syndrome have
(a) small uterus
(b) rudimentary ovaries
(c) underdeveloped breasts
(d) all of these.
Answer:
(d) all of these.

Question 63.
All genes located on the same chromosome
(a) form different groups depending upon their relative distance
(b) form one linkage group
(c) will not from any linkage groups
(d) form interactive groups that affect the phenotype.
Answer:
(b) form one linkage group

Question 64.
Conditions of a karyotype 2n±l and 2n + 2 are called
(a) aneuploidy
(b) polyploidy
(c) allopolyploidy
(d) monosomy.
Answer:
(a) aneuploidy

Question 65.
Distance between the genes and percentage of recontbfnatidnshows
(a) a direct relationship
(b) an inverse relationship
(c) a parallel relationship
(d) no relationship.
Answer:
(a) a direct relationship

Question 66.
If a genetic disease is transferred from a phenotypically normal but carrier female to only some of the male progeny, the disease is
(a) autosomal dominant
(b) autosomal recessive
(c) sex-linked dominant
(d) sex-linked recessive.
Answer:
(d) sex-linked recessive.

Question 67.
In sickle cell anaemia glutamic acid is replaced by valine. Which one of the following triplets codes for valine?
(a) GGG
(b) A AG
(c) G A A
(d) GUG
Answer:
(d) GUG

Question 68.
Person having genotype IA IB would show the blood group as AB. This is because of
(a) pleiotropy
(b) co-dominance
(c) segregation
(d) incomplete dominance.
Answer:
(b) co-dominance

Question 69.
ZZ/ZW type of sex determination is seen in
(a) platypus
(b) snails
(c) cockroach
(d) peacock
Answer:
(d) peacock

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Question 70.
A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents?
(a) TT and Tt
(b) Tt and Tt
(c) TT and TT
(d) Tt and It
Answer:
(b) TtandTt

Question 71.
In a dihybrid cross, if you get 9 : 3 : 3 : 1 ratio it denotes that
(a) the alleles of two genes are interacting with each other
(b) it is a multigenic inheritance
(c) it is a case of multiple allelism
(d) the alleles of two genes are segregating independently.
Answer:
(d) the alleles of two genes are segregating independently.

Question 72.
Which of the following will not result in variations among siblings?
(a) Independent assortment of genes
(b) Crossing over
(c) Linkage
(d) Mutation
Answer:
(c) Linkage

Question 73.
Mendel’s Law of independent assortment holds good for genes situated on the
(a) non-homologous chromosomes
(b) homologous chromosomes
(c) extranuclear genetic element
(d) same chromosome.
Answer:
(b) homologous chromosomes

Question 74.
Occasionally, a single gene may express more than one effect. The phenomenon is called
(a) multiple allelism
(b) mosaicism
(c) pleiotropy
(d) polygeny.
Answer:
(c) pleiotropy

Question 75.
In the F2 generation of a Mendelian dihybrid cross the number of phenotypes and genotypes are
(a) phenotypes – 4; genotypes – 16
(b) phenotypes – 9; genotypes – 4
(c) phenotypes – 4; genotypes – 8
(d) phenotypes – 4; genotypes – 9.
Answer:
(d) phenotypes – 4; genotypes – 9.

Bihar Board 12th Biology Objective Answers Chapter 5 Principles of Inheritance and Variation

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Bihar Board 12th Business Studies Model Papers

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Time : 3 Hour 15 Min
Full Marks : 100

Instructions

  1. Candidates are required to give their answers in their own words as far as practicable.
  2. Figures in the right hand margin indicate full marks.
  3. 15 minutes of extra time has been allotted for the candidate to read the questions carefull.
  4. This question paper has two sections : Section -A and Section-B.
  5. In Section-A, there are 50 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with black/blue ball pen against the correct option on OMR Sheet provided to you. Do not use Whitener/ Liquid/Blade/Nail on OMR Sheet, otherwise the result will be treated as invalid.
  6. In Section-B, there are 25 Short answer type questions, out of which any 15 questions are to be answered. Each question carries 2 marks. Apart from this, there are 08 Long answer type questions, out-of which any 04 of them are to be answered. Each question carries 5 marks.
  7. Use of any electronic device is prohibited.

Objective Type Questions

Question No. 1 to 50 have four options provided, out of which only one is correct. You have to mark, your selected option, on the OMR-Sheet. Each question carries 1 (one) mark. [50 x 1 = 50]

Question 1.
The essence of management is :-
(a) Co-ordination
(b) Organisation
(c) Staffing
(d) All of these
Answer:
(a) Co-ordination

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 2.
New Economic Ploicy is :-
(a) Liberalisation
(b) Privatisation
(c) Globalisation
(d) All of these
Answer:
(d) All of these

Question 3.
The organization steps are :-
(a) 2
(b) 4
(c) 6
(d) 8
Answer:
(b) 4

Question 4.
Training is a process
(a) Current
(b) Regular
(c) Continuous
(d) All of these
Answer:
(d) All of these

Question 5.
Controlling is necessary in :-
(a) Small enterprise
(b) Medium Enterprise
(c) Large Enterprise
(d) All of the above
Answer:
(d) All of the above

Question 6.
Characteristics of a sound financial planning are: –
(a) Simplicity
(b) Liquidity
(c) Economy
(d) All of these
Answer:
(d) All of these

Question 7.
First Function of financial management is :-
(a) Procurement of fund
(b) Financial forecasting
(c) Financial Control
(d) None of these
Answer:
(a) Procurement of fund

Question 8.
Co-ordination is :-
(a) Voluntary
(b) Necessary
(c) Unecessary
(d) Wastage of time
Answer:
(b) Necessary

Question 9.
By Scientific Management profits are :-
(a) Increased
(b) Decreased
(c) Not affected
(d) Revival
Answer:
(a) Increased

Question 10.
Economic Environment ofbusiness is influenced by :
(a) Economic policy
(b) Economic system
(c) Economic development
(d) All of these
Answer:
(d) All of these

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 11.
Staffing is the responsibility of.
(a) Lower management
(b) Middle management
(c) Top management
(d) All of these
Answer:
(d) All of these

Question 12.
According to George R. Terry, The type of planning are :-
(a) 08
(b) 06
(c) 04
(d) 02
Answer:
(d) 02

Question 13.
An organization is not helpful lor :-
(a) Co-ordination
(b) Contributes to morale
(c) Increase in corruption
(d) Incentive to growth
Answer:
(c) Increase in corruption

Question 14.
Employees Training is :-
(a) Necessary
(b) Unnecessary
(c) Compulsory
(d) Wastage of Money
Answer:
(c) Compulsory

Question 15.
Direction is related to employees :-
(a) Top level
(b) Middle level
(c) Lower level
(d) All level of above
Answer:
(d) All level of above

Question 16.
Organising process involves :-
(a) Grouping of indentical work
(b) Division of a work
(c) Assigning work to appropriate persons
(d) All of these
Answer:
(d) All of these

Question 17.
Fixed-capital is required for :-
(a) Payment of routine expenses
(b) Purchase of land
(c) Depositing in bank
(d) Payment to creditors
Answer:
(b) Purchase of land

Question 18.
SEBI is controller of :-
(a) Production
(b) Insider trading
(c) Capital marketing
(d) Government
Answer:
(c) Capital marketing

Question 19.
Entrepreneurship is an effort to create :-
(a) Risk
(b) Profit
(c) Jobs
(d) Business
Answer:
(c) Jobs

Question 20.
Working non-government organization in India is :-
(a) VOICE
(b) Common Cause
(c) A and B both
(d) None of these
Answer:
(c) A and B both

Question 21.
The Advantage of marketing is to :-
(a) Consumers
(b) Businessmen
(c) Manufacturers
(d) All of these
Answer:
(d) All of these

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 22.
Onwner’s Fund does not indued :-
(a) Share Capital
(b) Bank Loan
(c) Reserve Fund
(d) Share Premium
Answer:
(b) Bank Loan

Question 23.
Labelling is :-
(a) Compulsory
(b) Necessary
(c) Voluntary
(d) Wastage of Money
Answer:
(a) Compulsory

Question 24.
Consumer rights under Consumer Protection Act. are :-
(a) 08
(b) 07
(c) 06
(d) 10
Answer:
(a) 08

Question 25.
Social and economic development of a nation is the result of :-
(a) Entrepreneur
(b) Planning
(c) Operation
(d) Government
Answer:
(a) Entrepreneur

Question 26.
Advertising is done for :-
(a) Development of business
(b) Financial management
(c) Sales promotion
(d) Public relations
Answer:
(c) Sales promotion

Question 27.
Maximum period of treasury bill is :-
(a) One year
(b) Two years
(c) Five years
(d) Ten years
Answer:
(a) One year

Question 28.
Supervision is :-
(a) Necessary
(b) Unnecessary
(c) Wastage of time
(d) None of these
Answer:
(a) Necessary

Question 29.
Controlling is the function of
(a) Supervisor
(b) Sales man
(c) Mariager
(d) Employee
Answer:
(a) Supervisor

Question 30.
Steps Involved in selection process :-
(a) 07
(b) 09
(c) 06
(d) 10
Answer:
(a) 07

Question 31.
Depends on the sweet will of employees :-
(a) Divisional organisation
(b) Formal organisation
(c) Functional organisation
(d) Informal organization
Answer:
(d) Informal organization

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 32.
Planning is not :-
(a) Mental exercise
(b) Forward looking
(c) Wastage of time
(d) Choosing process
Answer:
(d) Choosing process

Question 33.
The need in development of a country is :-
(a) Physical resources
(b) Economic resources
(c) Efficient management
(d) All of these
Answer:
(d) All of these

Question 34
14 principles of management is propounded by :
(a) Henary Feyol
(b) F. W. Taylor
(c) Peter Drucker
(d) A. H. Maslo
Answer:
(a) Henary Feyol

Question 35.
Liberalisation policy in India has been :-
(a) Successful
(b) Unsuccessful
(c) Normal
(d) None of these
Answer:
(a) Successful

Question 36.
Planning is helpful to :-
(a) Achieving objectives
(b) In co-ordination
(c) Effective controlling
(d) All of these
Answer:
(d) All of these

Question 37.
Wages given to workers in Traditional Management are :-
(a) Low
(b) High
(c) Normal
(d) Maximum
Answer:
(d) Maximum

Question 38.
Which of the following is not features of organization : –
(a) Group of Individuals
(b) Group of Machine
(c) A Structure
(d) A process
Answer:
(b) Group of Machine

Question 39.
Objective of employee’s development is :-
(a) Increase in knowledge
(b) Better performance
(c) opportunity of promotions
(d) All of these
Answer:
(d) All of these

Question 40.
Which of the following is not external sources of recruitment: –
(a) Transfer of employees
(b) Direct recruitment
(c) Campus recuitment
(d) Contractual recruitment
Answer:
(a) Transfer of employees

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 41.
Type of communication are :-
(a) Written
(b) verbal
(c) Formal
(d) All of these
Answer:
(c) Formal

Question 42.
The leader possess :-
(a) Intelligence
(b) Foresightness
(c) Self-confidence
(d) Ail of these
Answer:
(d) Ail of these

Question 43.
In- effective communication language should not be :-
(a) Express
(b) Impressive
(c) Ambiguous
(d) Courtesy
Answer:
(d) Courtesy

Question 44.
Control is by employees.
(a) Opposed
(b) Supported
(c) Liked
(d) None of these
Answer:
(a) Opposed

Question 45.
The sources of working capital are :-
(a) Debtors
(b) Bank overdraft
(c) Cash sales
(d) All of these
Answer:
(a) Debtors

Question 46.
Capital market deals in
(a) Short term funds
(b) Medium term funds
(c) Long term funds
(d) None of these
Answer:
(c) Long term funds

Question 47.
Financial manager takes decision as to
(a) Finance
(b) Investment
(c) Dividend
(d) All of above
Answer:
(d) All of above

Question 48.
Consumer Protection Act was passed
(a) In 1886
(b) In 1986
(c) In 1996
(d) In 1997
Answer:
(b) In 1986

Question 49.
In India, entrepreneurial development programmer has been
(a) Successful
(b) Unsuccessful
(c) Need of improvement
(d) None of these
Answer:
(c) Need of improvement

Question 50.
Importance of Marketing concept is for
(a) Society
(b) Consumers
(c) Producers
(d) All of above
Answer:
(d) All of above

Non-Objective Type Questions

Short Answer Type Questions

Question no. 1 to 25 are Short answer type questions. Answer any 15 out of them. Each question carries 2 marks. (15 x 3 = 30)

Question 1.
Write the name of the level of manage-ment.
Answer:
Following are the level of management :

  1. Top Level Management
  2. Middle Level Management
  3. Lower Level Management.

Question 2.
Write any three points of the nautre of principles of management.
Answer:
Management of Principles : These are the statement of fundamental truth based on creation and systematic analysis which provides guidlines for managerial decision making and action.
Nature and charecteristics of management Principles are the same which are following :

  1. Flexibility
  2. Univarsal application
  3. lack of humanimity
  4. Beharourial.

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 3.
Write the name of any four factors of business environment.
Answer:
Principles of Management :

  1. Division of work : This means assigning the work to a person for which he is best suited. This principle is equally applicable to all hands of work managerial as well as technical.
  2. Unity of command : This means that sub-ordinates should be receive orders from one senior only. A sub-ordinate receiving orders from two or more bosses can satisfy none.
  3. Dicipline : Disciplines mean the observance of rules and regulations this principle emphasises the obedience on the part of the sub-ordinates.

Question 4.
Write name of any four merits of scientific management.
Answer:
Following are the merit of scientific management :

  1. Reduction in the cost of production.
  2. Better quality products.
  3. Benefits of division of labour.
  4. Avoidance of disputes between labour and management.

Question 5.
State any two types of planning on the basis of level of management.
Answer:
Types of planning on the basis of level of management are discussed below :

  1. Operational plan
  2. Tactical plan.
  3. Strategical plan

Question 6.
State any four points of importance of organization.
Answer:
Importance of organisation are discussed below :

  1. Makes the management simple and efficient.
  2. Encourage specilization.
  3. Improves constructive tainking.
  4. Increase productivity.

Question 7.
Write the name of any five advantage of organization in business.
Answer:
Advantages of organisation are following :

  1. Specilization
  2. Role clarity
  3. Clarifies authority and responsibility.
  4. Avoiding duplication of work.
  5. Co-ordination.

Question 8.
State any three qualities of a good leader.
Answer:
Qualities of a good leader are mention below:

  1. Physical features
  2. Knowledge
  3. Integrity
  4. Communication skills.
  5. Motivation skills.
  6. Initiative
  7. Self confidence
  8. Decisiveness
  9. Social skills.

Question 9.
State name of any two methods of ‘on-the- job training.
Answer:
Following are the two methods of “on job training”.

  1. Internship training method.
  2. Case study method.

Question 10.
State any three barriers of. communication.
Answer:
Effective communication is essential for effective and efficient management of an organisation.
There are a number of barriers to effective communications,
such as :

  1. Semantic barriers,
  2. Psychological or Emotional barriers,
  3. Organisational barriers
  4. Personal barriers.

Question 11.
State any two headings of the importance of supervision.
Answer:
Following are the two importance of supervision :

  1. Optimum utilization of Resoures : Supervision develops work skills which help in optimum utilization of resources.
  2. Controlling performance : Supervision insures performance of work as per the targets.
    Supervisior assumes responsibility for the accomplish ment of task. Undertaken and motivates his fellow workers.

Question 12.
Write any four headings of the importance of control in management.
Answer:
Following are the four heading of importance of control in management :

  1. Control is basis of planning.
  2. Facilitates decision making.
  3. Helps in improving efficiency.
  4. Appraisal of performance.

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 13.
Write name of any three methods/ techniques of control.
Answer:
Following are the methods/Techniques of control :

  1. Budgetary control.
  2. Break-even analysis.
  3. Statistical Data.
  4. Special reports and Analysis.
  5. Operational Audit or Internal Audit.
  6. Personal Observation.
  7. Policies, Procedures and Instructions.
  8. Ratio Analysis.
  9. Other Techniques.

Question 14.
Write the name of any three financial decisions taken by management.
Answer:
The three main financial decision which are generally taken by a finance manager are as under.,

  1. Investment Decision.
  2. Financial Decision.
  3. Dividend decision.

Question 15.
Write the name of any four factors which include in capital structure.
Answer:
Following are the four factors which include in capital structure :

  1. Position of cash flow.
  2. Cost of capital.
  3. Return on investment.
  4. Risk consideration.

Question 16.
Name the two factors affecting capital structure.
Answer:
Following are the two factors affecting capital structure.

  1. Cost of capital.
  2. Risk consideration.

Question 17.
State any four functions of financial market.
Answer:
Following are the four important functions of financial market :

  1. Mobilisation of savings and channelising them into most productive uses.
  2. Informational role for price recovery.
  3.  Providing liquidity to financial assets.
  4. Reducing the cost of transactions.

Question 18.
Write the two headings of the function of SEBI.
Answer:
Following are the two heading of SEBI functions :

  1. Protective functinsz.
  2. Development functions.

Question 19.
Name any four media of advertisement.
Answer:
Following are the four medium of advertising:

  1. Newspapers
  2. Magazines
  3. Television
  4. Radio.

Question 20.
State any two characteristics of a good brand.
Answer:
Following are the two features of good brand :

  1. It should be distinctive.
  2. It should be appropreate.

Question 21.
State any two objectives of consumer protection programme.
Answer:
The main two objectives of consumer protection act are as below :

  1. To ensure fair, competitive and responsible markets that work well for consumers and promote ethical business practice.
  2. To promote and protect the economics interests of consumers.

Question 22.
State any two characteristics of entrepreneurship.
Answer:

  1. Innovation : Any innovative work is entrepreneurship. New resources, new products, new technology, new utilities, new managerial skills etc., come in the perview of entrepreneurship. Thus, the basic feature of entrepreneurship is innovation.
  2. A high achievement function : Achievement orientation is the most important factor for explaining economic behaviour. ‘Doing things in a new and a better way’ and ‘decision-making under uncertainty’, can be regarded as two important features of entrepreneurship.

Question 23.
Name the needs which should be satisfied first.
Answer:
Following are five basic needs which should be satisfied first.

  1. Physological needs.
  2. Safety needs.
  3. Love and belongingness needs.
  4. Esteem needs.
  5. Self actualization needs.

Question 24.
Write any three merits of advertising.
Answer:
Following are the merits of Advertising :

  1. Introduces new product in the market.
  2. Expansion of the market.
  3. Increased sales.
  4. Fight competition.
  5. Enhance goodwill.
  6. Elimination of middlemen.
  7. Better quality products.
  8. Educate the consumers.

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 25.
Name any three sourcess of raising fixed capital.
Answer:
Following are the three sources of raising fixed capital :

  1. Issue of equity and preference shares.
  2. Issue of Debentures.
  3. Issue of Right shares.
  4. Retained Earning.

Long Answer Type Questions

Question no. 26 to 33 are Long answer type questions. Answer any 4 of them. Each question carries 5 marks. (4 x 5 = 20)

Question 26.
What is divisional organization ? State its main characteristics.
Answer:
Divisional Organisation/Departmentation: A department is a work group or unit which is created for performing certain functions of .similar nature. The process of division of the enterprise into different parts is broadly called departmentation.

The various parts or divisions are called as departments. It leads to grouping of both functions and personnel who are assigned to carry out allocated functions. It helps in creating a sound organisation structure. There can be many methods of departmentation. Every enterprise choose the appropriate basis or method depending upon its objectives, size, etc.

Merits :

  1. This arrangement makes effective control possible
  2. This arrangement is based on the principle of specialisation
  3. It estrablishes co-ordination on the departmental level.

Demerits :

  1. The weakness of one department affects the other departments
  2. All the departments function according to their sweet will making inter-departmental co-ordination difficult
  3. This system is q hurdle in the way of the complete development of the employees.

Question 27.
Explain the importance of decentralization.
Answer:
Decentralisation refers to the systematic effort to delegate to the lowest level all authority except which can be exercised at the central point.

The following factors highlight its importance :

  1. Greatern Motivation : Decentralisation improves the morale and motivation of Subordinates which is reflected in better work performance.
  2. Develops initiative among subordinates : Decentralisation helps to promote self-reliance and confidence amongst the subordinates. This is because when lower managerial levels are given freedom to take their own decisions, they learn to depend on their own judgement. It helps to promote initiative and creativity among them.
  3. Develops managerial talent for the future : As a result of decentralisation, employees get more opportunities to develop new skills. It makes them better future managers.
  4. Quick decision making : Decentralisation in an organisation, provides more freedom to lower level managers to take their own decisions. There is no need to get approval from higher level. It helps in quick and better decision making.
  5. Facilitates growth and expansion : Decentralisation facilitates organisational growth through expansion and diversification.

Question 28.
Explain in brief the various methods of training.
Answer:
There are various methods of training. These are broadly categories into two groups :

  • On the job.
  • off-the job methods.

On the job methods :

  1. Apprenticeship programmes: Apprenticeship programmes put the trainee under the guidance of master worker. These are designed to acquire a higher level of skill.
  2. Coaching : In this method, the superior guides and instructs the trainee as a coach. The coach or counseler sets mutually agreed upon goals.
  3. Internship training : It is a joint programme of training in which educational instigutions and business firms cooperate.
  4. Job rotation : This kind of training involves shifiting the trainee from one department to another of from or one job to another.

Off the job methods:

  1. Class room lectures/conferences: The lecture or conference approach is well adapted to conveying specific information rules, procedures or methods.
  2. Films : They can provide information and explicitly demonstrate skills that are not easily represened by the other techniques.
  3. Case study : Taken from actual experiences of organisations, cases represent attempts to describe,
    as accruetly as possible real problems that managers have faced.
  4. Computer modelling: It simulates the work environment by programming a computer to imitate some of the realities of the job and allows learning to take place without the risk or high costs.
  5. Vestibule training : Employees learn their jobs on the equipment they will be using, but the training is conducted away from the actual work floor.
  6. Programmed instruction : The method incorporates a prearranged and proposed acuisition of some specific skills or general knowledge.

Question 29.
Discuss the importance of directing.
Answer:
Following are the importance of Directing :

  1. Managerial function : Directing is a managerial function. It is through directing, the managers guides, inspires and leads the employees to perform the task assigned.
  2. Continuing function : Directing is a continuous function. The managers continuously guide, inspire and lead the employees to get the work done.
  3. Integrating process : Directing is an integrating process. It integrates the efforts of the employees to achieve the organisational objectives. It provides direction to their efforts. In the absence of direction, their efforts may not focus or concentrate on the objectives of the organisation and may remain inactive.
  4. Pervasive function : Directing is a responsibility of all managers. It is performed at all levels of the organisation. Directing flow from top to lower levels of management.
  5. Creative function : Driecting is a creative function. It converts paper plans into reality by initiating, guiding, leading and supervising.

Question 30.
Explain any four needs that motivate an employee to work.
Answer:
Froms of Non-financial Incentives: In order to motivate the employees management may use the following forms of non-financial incentives :

(i) Praise of appreciation of work done : Recognition of satisfactory performance acts as non- financial incentive since it satisfies one’s ego needs. However, this incentive should be used with great care because praising an incompetent employee creates resentment among competent employees.

(ii) Workers’ participation in management : Participation in management provides strong motivation to the employees. Gives them psychological satisfaction if there voice is header participants in management provides for two ways communication and so imbibes a sense of importance.

(iii) Suggestion system : Suggestion system is an incentive with satisfies many needs of the employees. Many organisations which use the suggestion system make use of cash awards for useful suggestion. They sometimes publish the workers name with the photograph in the company magazine. This motivates the employees to be in search for something which may be of greater use to the organisation.

(iv) Competition : If there is healthy competition among individual employees, group of employees, it leads them to achieve their persoanl or group goals. Hence, competition acts as none financial incentives.

(v) Opportunity for growth : Opportunity for growth is another kind of intensive. If the employees are provide opportunity for their advertisement and growth to develop their personality, they feel very much satisfied and more communicate to organisation goals.

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 31.
Explain the functions of financial manager.
Answer:
Finances are the cornerstone of every business. The prime goal of my organization would be to garner huge profits and this is only possibe withh proper management of the finance. Therefore, effectual finance Management is imperative for every organization as it leads to enhanced profits are reduction in the operational cost.

A finance manger plays an impoertant role in the mangement of a business organbization as he manges all the activites related to finance. There are many functions that a financial manager is expected to perform .
These include.

1. Estimating the amount of capital required for the proper functioning of the business : The most basic function of a finance manager is the estimation of the capital because funds are required for both long term and short term. The firm requires capital so that it can its liability with no delay, benefit from early business opportunites, pay for resources, op-erational cost etc.

2. Devising a capital structure : For the determining the capital structure, the finance manager must ensure that the earning rate is higher than the rate of interest on the borrowed amount.

3. Sources to raise funds : For proper financial management, it is imperative to find can raise funds. The organisatiion can raise funds through different sources including equity and preference shares, debentures, banks, financial institutions other souces.

4. Acquisition of funds : While acquiring funds, the financial manager needs to follow some basic step such as legal formalities and documentation’ required.

Question 32.
What is working capital ? How is it calculated ?
Answer:
Meaning of Working Capital : Working capital refers to that capital which is utilized for meeting current liabilities by cash payments in the ordinary course of business. In other words, the working capital is invested in raw materials, in stock of partly finished goods in meeting day-to-day or current exenditure on salaries, wages, rent, rates, taxes, insurance, advertisement etc. in cash.
Determinants of Working Capital
(1) Size of Business : Larger of the business enterprise, greater would be the need for working capital. The size of a business may be measured in terms of scale of its business operations.

(2) Production Cycle : Production cycle means the time-span between the purchase of raw materials and its conversion into finished goods. The longer the production cycle, the larger will be the need for working capital.

(3) Production Policy : The need for working capital is also determined by production policy. The demand for certain products (such as woolen garments) is seasonal. Two type of production policies may be adopted for such products.

(4) Availability of Raw Material : If the raw material required by the firm is available easily on a continuous basis, there will be no need to keep a large inventory of such materials and hence the requirement of working capital will be less. On the other hand, if the supply of raw material is irregular, the firm will be compelled to keep an excessive inventory of such materials which will result in high level of working capital.

(5) Availability of Credit from Banks :If a firm can get easy bank credit facility in case of need, it will operate with less working capital

Bihar Board 12th Business Studies Model Question Paper 1 in English Medium

Question 33.
Explain any five functions of marketing.
Answer:
Function of Marketing:
(i) Gatrhering and analysing market information : An important function of a marketer is gather and analyse market information. It is necessary to identify the needs the customers and to take various decisions for the successful marketing of the products and services.

(ii) Marketing planning : Marketing manager has to develop appropriate marketing plans to achieve the marketing objectives of the firm.

(iii) Customers support services : Another very important function of marketing management relates to developing customers support serves such as procuring credit service after sales services, handling customer complaints, maintenance services, technical services and consumer information. All these services aim at providing maximum satisfaction to the customers.

(iv) Physical distributions : A very important function of marketing is to arrange for distribution o f goods and services. Physical distribution includes decisions regarding choice of channels of distribution, maintaining inventory, storange, warehousing etc.

(v) Utilising funds : It is the task of the finance manager to ensune that the funds are inuested wisely so as to garner maximum roll.

(vi) Disposing of Profits : Effectcial finance management involves Inalysing the funds that can be invested for proper working of the organization and distributing the rest amoung the shareholders.

(vii) A financial manager needs to manage the cash in such a way that there its neither shortage nor surplus and decily expenses can be met without any hassles.

(viii) Finance Management involves avaluation and control of the financial perform once of an organization

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Bihar Board 12th Economics Model Papers

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Time : 3 Hour. 15 Min
Full Marks : 100

Instructions

  1. Candidates are required to give their answers in their own words as far as practicable.
  2. Figures in the right hand margin indicate full marks.
  3. 15 minutes of extra time has been allotted for the candidate to read the questions carefully.
  4. This question paper has two sections : Section-A and Section-B.
  5. In Section-A, there are 50 objective type questions which are compulsory, each carrying 1 mark. Darken the circle with black/blue ball pen against the correct option on OMR Sheet provided to you Do. not use Whitener/Liquid/Blade/Nail on OMR Sheet, otherwise the result will be treated as invalid.
  6. In Section-B, there are Non-objective type questions. There are 25 Short answer type questions, out of which any 15 questions are to be answered. Each question carries 2 marks. Apart froms this, there are 08 Long answer type questions, out-of which any 04 of them are to be answered. Each questions carries 5 marks.
  7. Use of any electronic device is prohibited.

Objective Type Questions

Question No. -1 to 50 have four options provided, out of which only one is correct. You have to mark, your selected option, on the OMR-Sheet. Each questiion carries 1 (one) mark. [50 x 1 = 50]

Question 1.
Which is a central problem of an economy ?
(a) Allocation of Resources
(b) Optimum utilization of Resources
(c) Economic development
(d) All of these
Answer:
(d) All of these

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 2.
Which of the following is a source of production ?
(a) Land
(b) Labour
(c) Capital
(d) All of these
Answer:
(d) All of these

Question 3.
According to whom, Economics is a science of human welfare ?
(a) A. Marshall
(b) Paul Samuelson
(c) J.S.Mill
(d) Adam Smith.
Answer:
(a) A. Marshall

Question 4.
Which of the following is not a factor of production ?
(a) Land
(b) Labour
(c) Money
(d) Capital
Answer:
(c) Money

Question 5.
The word ‘micro’ was first used by __________
(a) Marshall
(b) Boulding
(c) keynes
(d) Ragnar Frisch
Answer:
(d) Ragnar Frisch

Question 6.
Consumer’s behaviour is studied in __________
(a) Micro-economics
(b) Income theory
(c) Macro-economics
(d) None of these
Answer:
(a) Micro-economics

Question 7.
Elasticity of demand for necessary goods is __________
(a) zero
(b) unlimited
(c) greater than unity
(d) less than unity
Answer:
(a) zero

Question 8.
Which of the following factors affects elasticity of demand ?
(a) Nature of goods
(b) Price level
(c) Income level
(d) All of these
Answer:
(d) All of these

Question 9.
Law of demand is a __________
(a) Qualitative statement
(b) Quantitative statement
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 10.
In production function, production is a function of __________
(a) price
(b) factors of production
(c) total expenditure
(d) None of these
Answer:
(b) factors of production

Question 11.
At which time all the factors of production may be changed ?
(a) Short run
(b) Long run
(c) Very long run
(d) All of these
Answer:
(a) Short run

Question 12.
Average variable costs can be defined as __________
(a) TVC x Q
(b) TVC + Q
(c) TVC – Q
(d) TVC -r Q
Answer:
(d) TVC -r Q

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 13.
For a firm’s equlibrium __________
(a) MR = MC
(b) MR > MC
(c) MR < MC
(d) MR = MC = 0
Answer:
(a) MR = MC

Question 14.
Supply is associated with __________
(a) a time period
(b) price
(c) both (a) and (b)
(d) none of these
Answer:
(c) both (a) and (b)

Question 15.
Determining factor of supply of goods is __________
(a) Price of goods
(b) Price of related goods
(c) Price of factors of production
(d) All of these
Answer:
(d) All of these

Question 16.
Which is a characteristic of the market ?
(a) One area
(b) Presence of Buyers and” Sellers
(c) Single price of the commodity
(d) All of these
Answer:
(d) All of these

Question 17.
Which one is a feature of monoplistic competition ?
(a) Differentiated product
(b) Selling cost
(c) Imperfect knowledge of the market
(d) All of these
Answer:
(d) All of these

Question 18.
Which is a reason of change in demand ?
(a) Change in Consumer’s Income
(b) Change in price of related goods
(c) Population increase
(d) All of these
Answer:
(d) All of these

Question 19.
Net National Income at factor cost is called __________
(a) National Income
(b) Gross Investment
(c) Income
(d) None of these
Answer:
(a) National Income

Question 20.
Depreciation expenses are included in __________
(a) GNPMP
(b) NNPMP
(c) NNPpc
(d) none of these
Answer:
(a) GNPMP

Question 21.
Which one is included in three sector model ?
(a) Family
(b) Goverment
(c) Firm
(d) None of these
Answer:
(b) Goverment

Question 22.
Which service is included in Tertiary sector ?
(a) Mining
(b) Construction
(c) Communication
(d) Animal Husbandry.
Answer:
(d) Animal Husbandry.

Question 23.
Which method is adopted in measuring National Income ?
(a) Production method
(b) Income method
(c) Expenditure method
(d) All of these
Answer:
(d) All of these

Question 24.
“Money is what money does”- Who said it ?
(a) Hawtrey
(b) Keynes
(c) Hartley Withers
(d) Prof. Tinbergen
Answer:
(c) Hartley Withers

Question 25.
Which is the primary function of commercial banks ?
(a) Accepting deposits
(b) Advancing loans
(c) Credit creation
(d) All of these
Answer:
(d) All of these

Question 26.
The full form of ATM is __________
(a) Any Time Money
(b) All Time Money
(c) Automated Teller Machine
(d) both (a) and (b)
Answer:
(c) Automated Teller Machine

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 27.
Reserve Bank of India was established in __________
(a) 1947
(b) 1935
(c) 1937
(d) 1945
Answer:
(b) 1935

Question 28.
Micros which means ‘small’ belongs to which language ?
(a) Arabic
(b) Greek
(c) German
(d) English
Answer:
(b) Greek

Question 29.
How many types of elasticity of demand is there ?
(a) Three
(b) Five
(c) Six
(d) Seven
Answer:
(b) Five

Question 30.
Which money is issued by the central bank ?
(a) Currency
(b) Credit money
(c) Coins
(d) All of these
Answer:
(b) Credit money

Question 31.
RBI announced the guidelines to issue itences to new banks of Private Sector on __________
(a) January 22, 1993
(b) March 15,1995
(c) April 1,1999
(d) None of these
Answer:
(a) January 22, 1993

Question 32.
Banking Sector Reforms in India began in __________
(a) 1969
(b) 1981
(c) 1991
(d) 2001
Answer:
(c) 1991

Question 33.
“Supply creates its own demand” Who gave this law ?
(a) J. B. Say
(b) J.S.Mill
(c) Keynes
(d) Ricardo.
Answer:
(c) Keynes

Question 34.
On Which factor does Keyneaian theory of employment depend ?
(a) Effective demand
(b) Supply
(c) Production efficiency
(d) None of these
Answer:
(a) Effective demand

Question 35.
Who is the writer of the book. ‘Traited Economic Politique’ ?
(a) Pigou
(b) J. B. Say
(c) Keynes
(d) Ricardo
Answer:
(b) J. B. Say

Question 36.
If MPC = 0.5 then mulutiplier (k) will be __________
(a) i-
(b) 0
(C) f
(d) 2
Answer:
(d) 2

Question 37.
On which concept does classical viewpoint depend ?
(a) Say’s law of market
(b) Perfect Flexibility of wage Rate
(c) Perfect Flexibility of Interest Rate
(d) All of these
Answer:
(b) Perfect Flexibility of wage Rate

Question 38.
Which is included in indirect tax ?
(a) Income tax
(b) Wealth tax
(c) Excise duty
(d) Gift tax
Answer:
(c) Excise duty

Question 39.
Which one is the item of Current Account ?
(a) Import of visible items
(b) Expenses of tourists
(c) Export of visible items
(d) All of these
Answer:
(d) All of these

Question 40.
Balance of trade means __________
(a) capital transaction
(b) import & export of goods
(c) total debit and credit
(d) all of these
Answer:
(d) all of these

Question 41.
What is price flexibility of a necessities of demanded things ?
(a) Zero
(b) Infinite
(c) More then a unit
(d) less than unit
Answer:
(a) Zero

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 42.
‘Profit is the award of bearance risk’ who said this ?
(a) Halley
(b) J. B. Clark
(c) Knight
(d) None of these
Answer:
(c) Knight

Question 43.
The market situation in which there is only are consumer is called __________
(a) Monopoly
(b) Monopsani
(c) Duopoly
(d) None of these
Answer:
(c) Duopoly

Question 44.
On which matter it is decide of general value, __________
(a) market day
(b) short-term market
(c) long term market
(d) none of these
Answer:
(b) short-term market

Question 45.
Following is not a source of origin __________
(a) Land
(b) Labour
(c) Money
(d) Capital
Answer:
(c) Money

Question 46.
Who the Central Bank of India ?
(a) SBI
(b) Central Bank of India
(c) Reserve Bank of india
(d) None of these
Answer:
(c) Reserve Bank of india

Question 47.
When was establish Reserve Bank of India ?
(a) In 1932
(b) In 1935
(c) In 1945
(d) In 1956
Answer:
(b) In 1935

Question 48.
In which year the nationalisation of the commercial bank:
(a) 1960
(b) 1968
(c) 1969
(d) 1980
Answer:
(c) 1969

Question 49.
Central Bank can control by which __________
(a) Bank Rate
(b) Open market
(c) CRR
(d) All these
Answer:
(d) All these

Question 50.
When was establish State Bank of India ?
(a) 1950
(b) 1955
(c) 1960
(d) 1965
Answer:
(b) 1955

Non-Objective Type Questions

Short Answer Type Questions

Question no. 1 to 25 are Short answer type questions. Answer any 15 out of them. Each question carries 2 marks. (15 x 3 = 30)

Question 1.
State any four difficulties of Barter System.
Answer:
The four difficulties of Barter system are as follows:

  1. Lack of Double Coincidence : The barter system requires a double coincidence of wants on the part of those who want to exchange goods or services. lt is necessary for a person who wishes to trade his goods or service to find some other person who is not willing to buy his goods or service,but also possesses that goods which the former wants.
  2. Difficulties in store value : A major difficulty in barter system appears because store of purchasing power for future can not be made due to perishable nature of most of the goods.
  3. Lack of common acceptability unit of value : Due to lack of common acceptable unit of value ,it becomes difficult to determine.The value of commodity to be exchanged.
  4. Lack of divisibility in commodities: Another difficulty of barter system relates to the fact that all commodities can not be divided or sub-divided.

Question 2.
What is law of supply ? Explain it with illustration.
Answer:
The law of supply states, that other things remaining constant, the higher the price, the greater the quantity supplied or the lower the price, the smaller the quantity supplied.Law of supply states the positive relationship between price of the commodity and its supply.Producer always wants to sell his commodity at a higher price and less at a lower price .Thus,price of commodity and its supply are positively related.In functional form.S = f (P) Where S refers to supply of the commodity and P for price.Thus,supply function of a commodity represents a direct relationship between supply of commodity and its price.

The law of supply can also be explained with ‘Supply schedule’ and ‘Supply Curve.
Bihar Board 12th Economics Model Question Paper 5 in English Medium 1
Above table shows individual supply schedule, that explains supply of commodity increases with increase in price.

Question 3.
Discuss the main features of government budget.
Answer:
The main features of Government budget are as follows:

  1. Encouragement to economic development: The basic objective of the budget is to accelerate the pace of economic development in the country.For accelerating the pace of economic development:
    • government may grant tax rebates to productive activities
    • government may develop infrastructure like roads .bridges etc.
    • government may establish public enterprises.
  2. Balanced Regional Development : Through budget .government may promote the development in backward areas for ensuring balanced regional development in the economy. Engorgement may grant tax rebates to these areas,may establish public enterprises in these areas and may allocate more funds for infrastructural development in these backward areas.
  3.  Re- distribution of income and property : Budget plays a vital role in reducing the economic disparities in the economy.Many steps can be taken in the budget for reducing the economic disparities in the economy.
  4. Economic Stability: Economy faces the cycles of boom and depression and the budget aims to put a control on these cycles.
  5. Creation of employment : Employment creation is one of the important objectives of government budget.Govemment may promote labour – intensive techniques in public works programmes and may also initiate programmes in the economy.

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 4.
Distinguish between primary sector and secondary sector.
Answer:
Difference between Primary sector and secondary sector are as follows :
Primary sector :

  1. It is that sector which exploits natural resources and produce goods and services.
  2. It is known as agriculture and allied sector.
  3. It includes all agricultural and allied activities such as forestry,mining,quarrying,fishing,animal husbandry etc.
  4. Unorganised and traditional techniques.
  5. No possibility of division of labour.

Secondry sector :

  1. It is that sector which transforms one goods into another for creating more utility from it.
  2. Famously known as manufacturing sector.
  3. It includes manufacturing units small scale units, large firms ,big corporate, multinational corporation.
  4. Organised techniques.
  5. Complex division of labour can be used for production.

Question 5.
What is National Income ?
Answer:
National income is the sum of factor incomes earned by normal residents of a country during the period of one year.

Bihar Board 12th Economics Model Question Paper 5 in English Medium 2
NY = National income
Z = Sum or total (Z is called sigma)
FY = Factor income
n = all normal residents of a country.
Rent, interest, profit and wages are the factor incomes. So, national income is the sum of rent, interest, profit and wages earned by normal residents of a country during an accounting year.

According to the central statistical organisation (the official agency engaged in the estimation of national income in India) defines national income as under: “National income is the sum of factor income earned by the normal residents of a country in the form of wages, rent, interest and profit in an accounting year.”

Question 6.
Define the functions of Central Bank.
Answer:
Principal function of the central bank are as follows :

  1. Issuing of notes : In modem times, central bank alone has the exclusive right to issue notes in every country of the world. The notes, issued by the central bank are unlimited legal tender throughout the country. Central bank of the country enjoys monopoly right of note issuing.
  2. Banker to the Government: Central bank acts as a banker, agent and financial advisor to the government. As a banker to the government, it keeps the accounts of all government banks and manages government treasuries. It performs the some functions for the government as the commercial banks do for their customers.
  3. Banker’s bank : It performs the function of a banker to all other banks in the country. Central bank has almost the same relation with all other banks as a commercial bank has with its customers. It keeps part of the cash balances of all commercial banks as deposit with a view to meeting liabilities of these banks in times of crisis.
  4. Supervision of the banks : As a banker’s bank, the central bank also supervises the commercial banks.
    The supervision of commercial banks relates to

    • licensing of the commercial banks
    • expansion of the commercial banks in terms of their branches across different parts of the country.
  5. Lender of the last resort : The central bank also acts as lender of last resort for the other banks of the country. It means that if a commercial bank fails to get financial accommodation form anywhere, it approaches, the central bank as a last resort.

Question 7.
Explain law of demand.
Answer
The law of demand stages that, other things being equal the demand for a good extends with a decrease in price and contracts with an increase in price. There is inverse relationship between quantity demanded of a commodity and its price, provided other factors influencing demand remain unchanged.

The law of demand states that other things remaining constant, quantity demanded of a commodity increases, with a fall,in price and diminishes when price increases.

Question 8.
What do you mean by Macro-economics ?
Answer:
The term Macro in English has its origin in the Greek term Macros which means large. In the context of macro economics “large” means economy as a whole. Thus, macro economic is defined as that branch of economics which studies economic activities at the level of an economy as a whole.

According to M. H. Spencer, “Macro-economics is concerned with the economy as a whole or large segments of it. In Macroeconomics, attention is focused on such problems as the level of unemployment, the rate of inflation, the nation’s total output and other matters of economy-wide significance.”

Question 9.
Explain the functions of money.
Answer:
Functions of money are classified into following two categories:

  1. Primary or main functions,
  2. Secondary or subsidiary functions.

1. Primary or main functions : This category includes those functions of money, which are common to all countries during all periods.

  • Medium of exchange : Medium of exchange is an important function of money. It means that money acts as an intermediary for the goods and services in the exchange transaction. The medium of exchange function of money has classified all transactions on the basis of time and place.
  • Measure of value or unit.of value : Unit of account means that the value of each good as service is measured in the monetary unit. Money measures the value of everything or the prices of all goods and services can be expressed in terms of money.

2. Secondary Functions : These functions are supplementary to primary functions. These are as follow.

  • Standard of Deferred Payment : Deferred payment means those payments which are to be made in futuse.
  • Store of Value : Human beings has a tendancy to save a part of his income for future to fulfil his future requirements. Store of value can take place only when person becomes confident to use his saving as per his requirements in future.
  • Transfer of Value : Money is a licuid means of exchange. Hence, purchasing power of money can easirly be transferred from one person to another or one place to the other. Thus, in modem times, money has become the best means of tranferring the value of money.

Question 10.
Write the sources of production.
Answer:
There are five types of the factor of production :

  1. Land
  2. Labour
  3. Capital
  4. Organisation
  5. Enterprise.

Land, labour, capital, machines tools, equipments and natural means are limited. Every demand of every individual in the economy cannot be satisfied, so the society has to decide what commodieits are to be produced and to what extent. Goods purchased in an economy can be classofied as consumer goods and produce goods. These goods may be further classified as single use goods and durable goods.

It is undoubtedly the basic problem of the economy. If we produce one commodity, it will mean that we are neglecting the production of the other commodity. We assume that all the factors of production in the economy are fully absorbed, so if we want to increase the production of one commodity, we will have to withdraw resources from the production of the other commodity on the basis of 4 requirements goods are further classified as goods for necessaries comforts and luxuries.

Question 11.
Write the Functions of money.
Answer:
Primary function of money are also called prime functions. These functions are of prime importance and common to all countries during all the periods. Money has two primary functions.

  1. Medium of exchange : Money acts as a medium of exchange. In modem days, exchange is the basis of entire economy and money makes this exchange possible. At old age barter system was in practise in which goods were exchanged for goods but due to lack of double co¬incidence exchange was difficult. But the uses of money has removed this difficulty. In modem times, money performs all function of exchange in the economy.
  2. Measure of value : Money acts unit of measure of value. In other words it acts as a yardstick of standard measures of value to which all other things can be measured. In barter system the general measurement of value was absent and consequently it was difficult to measure the value of exchange. In modem times, the value of every commodity can be measured in money, with the use of money, economic calculations for measuring values have become simplified

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 12.
What do you mean by NNP ?
Answer:
Net National product at factor cost (NNPFC) is the sum of total factor income (rent + interest + profit + wages) genrated within the domestic territory of a country along with net factor income from abroad during a year. NNP is the sum of total factor incomes earned.by normal residents of a country during a year.
NDPFC + Net factor income from abroad = NNPFC

Question 13.
Explain the importances of Government Budget.
Answer:
The notable objective and importance of government budgets are as follows :

  1. Redistribution of income and wealth: Equitable distribution of income and wealth is a sign of social justice which is the principal objective of any welfare state as in India.
  2. Reallocation of resources : The government of a country directs the allocation of resources in a manner such that there is a balance between the goals, of profit maximization and social welfare.
  3. Economic stability : These refer to the phases of recession, depression, recovery and boom in the economy. Budget is used as an important policy instrument to combat the situations of deflation and inflation. By doing it the government tries to achieve the state of economic stability.
  4. Managing public enterprises : The budgetary policy of the government shows interest of the government to increase the rate of growth through public enterprises.

Question 14.
Explain the merits or advantages of perfect competition.
Answer:
The following are the main advantages of. perfect competition:

  1. Large number of firms or sellers : The number of firms selling a particular commodity is so large that any increae or decrease in the supply of one particular firm hardly influences the total market supply.
  2. Large number of buyers : Not only is the number of sellers very large, also, the number of buyers is very large. Accordingly, like an individual firm, an individual buyer is also not able to influence price of the commodity. Accordingly an individual buyer under perfect competition is also a price taker.
  3. Homogeneous product : All sellers sell identical units of a given product. Seeling homogeneous product at the given price rules out the possibility of advertisement or other sale-promotion expenses. So, that there are selling costs, in perfectly competitive market.
  4. Perfect knowledge : Buyers and sellers are fully aware of the price prevailing in the market. Buyers know it fully well at what price sellers are selling a given product.
  5. Free entry and exit of firms : A firm can enter and leave any industry. There is no legal restriction on the entry or exits.
  6. Perfect mobility : Factors, of production are perfectly mobile under perfect competition.

Question 15.
What is GDP ?
Answer:
Gross Domestic Product (GDP) is the market value of the final goods and services produced during a year within the domestic territory of a country.

GDP is the market value of the final goods and services produced within the domestic territory of a country during one year inclusive of depreciation. There are both resident as well as foreign producers within the domestic territory of a country. In India, for example, there are many international banks as well as multinational companies. Gross domestic product includes the market value of the final goods and services produced by all such producers.

Question 16.
Explain the four difficulties of barter exchange.
Answer:
The four difficulties of barter exchange are as follows:

  1. Lack of double coincedence : The barter system requires a double coincidence of wants on the parts of those who want to exchange goods or services. It is necessary for a person who wishes to trade his goods or services. It is necessary for a person who wishes to trade his goods or services, but also possesses that goods which the farmer wants.
  2. Difficulties in store of value: A major difficulty in barter system appears because store of purchasing power for future can not be made due to perishable nature of most of the goods.
  3. Lack of common acceptability unit of value :
    Due to lack of common acceptable unit of value, it becomes difficult to determine. The value of commodity to be exchange for example how will it be determined that how much wheat will be exchanged for are metre of cloth and vice versa.
  4. Lack of divisibility in commodities : Another difficulty of barter system relates to the fact that all commodities can not be divided or sub-divided. If the commodity is divided, its utility is lost.

Question 17.
What is law of supply ?
Answer:
The law of supply states that other things remaining constant, quantity supplied of a commodity increases with increase in the price and decreases with a fall in its price.

Law of supply states that, other things remaining constant, there is a positive relationship between price of a commodity and its quantity supplied. Thus, more is supplied at higher price and less at the lower price. There is positive relation between the price and quantity supplied. The law of supply only explain the extension and contraction of supply in response to increase and decrease in price of the commodity. It does not explains increase or decrease in supply.

Supply curve (SS) slopes upward and shows increases in quantity supplied in response to increase in price of the commodity. Thus, quantity supplied increases, when price rises.

Question 18.
Write the advantages of government budget.
Answer:
Advantages of government budget : Budgets plays a decision-making role in planned economy. The goals of economic development in a planned economy may be achieved with the basic instruments of budget. A budget in a planned economy may contain the following advantages.

  1. In a planned economy budget is based on the broad objectives of national planning.
  2. In initials phase of economic development, planning is supported by deficit budget which is brought to near balanced budget in the later stage of development.
  3. In a planned economy a policy of Justice in Taxation is adopted while making budget and for it the policy of progressive taxation is adopted.
  4. Budget also plays a positive role in performing the economic activities in the country.

Question 19.
Explain difference between primary and secondary sector.
Answer:
Differences between Primary and Secondary sector are as follows :
Primary Section :

  1. It is that sector which exploits natural resources and produce goods and services.
  2. It is known as agriculture and allied sector.
  3. It includes all agricultural and allied activities such as forestry, mining, quarrying, fishing, animal husbandry etc.
  4. Unorganised and traditiona techniques.
  5. No possibility of division of labour.

Secondary Sector :

  1. It is that sector which transforms one goods into another for creating more utility from it.
  2. Famously known as manufacturing sector.
  3. It includes manufacturing units, small scale units, large firms, big carporates, multinational corporation.
  4. Organised techniques.
  5. Complex divisin of labour can be used for production.

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 20.
Define various types of credits in bank.
Answer:
Principal instruments of monetary policy or credit control of the central bank of a country are broadly classified as:

(a) Quantitative instruments and
(b) Qualitative instruments

(a) Quantitative instruments of monetary policy : There are those instruments of monetary policy which affect supply of money in the economy. These important of monetary policy are as follows :

  • Bank rate : The bank rate is the minimum rate at which the central bank of a country (as a lender of last resort) is prepared to give credit to the commercial banks.
  • Open market operations : Open market operations refer to the sale and purchase of securities in the open market by the central bank. Cash balances are high powered money on the basis the which commercial banks create credit.

(b) Qualitative Instruments of monetary policy :

  • Margin Requirements : The margin requirement of loan refers to the difference between the current value of the security offered for loans and the values of loans granted.
  • Rationing of credit: Rationing of credit refers to fixation of credit quotas for different business activities.

Question 21.
What is meant by limitations in Economics ?
Answer:
Economics has classified in two branches :

  1. Micioecoomics
  2. Macroeconomics

Limitations of Micro economic are as follows : Micro economic analysis fails to adopt the shape of “Universal Analysis” due to its various limitations are as follows:

  1. Study not of whole but of a fraction : Micro economics studies only a fraction of a economy and does not study the entire economy. The entire economy can not be represented by studying only individual units.
  2. Inadequate analysis : Micro economic analysis is an inadequate analysis because conclusions derived from individual units may not be applicable to entire economy.

Limitations of Macroeconomic are as follows :

  1. Macro Economic Paradoxes : Sometimes aggregates provide misleading conclusions. What is true for an individual may not be true for the entire group.
  2. Individual units are ignored: Macro economics puts an emphasis on the entire society while individual units, which make the society, are ignored.

Question 22.
What is the difference between Direct tax and Indirect tax.
Answer:
Distinctinction between Direct tax and Indirect tax: .

Direct Taxes :

  1. The are directly paid to government by the person on whom it is imposed.
  2. They are generally progressive. The rate of tax increase with increase in income.
  3. They cannot be shifted on to others.

Indirect Taxes:

  1. They are paid to the government by one person but their burden is borne by another person.
  2. They are generally regressive. The rate of tax decreases as income increases.
  3. They can be shifted on to others.

Question 23.
Explain the functions of commercial banks.
Answer:
The functions of commercial banks are as follows :

(i) Accepting deposits : The prime function of the commercial bank is to accept deposits from bank.
The various types of deposits accepted by the commercial bank are as follows :

  • Current Deposits : Deposits in current account are termed as current deposits. A depositer can deposit the amount any member of times he likes and can also withdraw the amount any number of times he wants.
  • Saving deposits: Such accounts generally belong to the people having small savings and who do not require withdrawal of money many times.
  • Fixed deposits : In fixed accounts, account is deposited for a certain fixed period. Depositor gets deposits receipt while depositing cash in such accounts.
  • Recurring deposit : Recurring deposits are certain type of fixed deposit. Depositor deposits certain amount every month in this account.

(ii) Granting loans : The second important primary function of commercial banks is advancing of loans. After keeping certain cash reserves, the banks lend their deposits to needy borrowers.
Various types of loans granted by banks are as follows :

  • Cash credit : In cash credit system, bank provides, loans to the borrower against bonds or some other types of securities.
  • Overdraft: Customers having current account with the bank are granted the facility of withdrawing more money than the amounts lying in their accounts.
  • Loans and advances : A particular, amount is given by banks as loan and advances which is deposited in customer’s account.
  • Discounting the bills of exchange : Bank discounts the bill of exchange i.e. after making some marginal deductions, the pays the value of the bill to the holder.
  • Investment in government securities : Banks also grant loan to the government. The buying of government securities by banks is termed as ‘Earning to the government:’

(iii) Credit creation : In present times, credit creation has become the prime function of commercial banks. Banks invite primary deposits from the public and grant loan many times than these, priihary deposits on the basis of credit multiplier.

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 24.
What are main advantages of balance of payments.
Answer:
The main advantages of Balance of Payment are as follows :

  1. Systematic record : It is a record of payment and receipts of a country related to its import and export with other country.
  2. Fixed period of time : It is amount of a fixed period of time generally a year.
  3. Comprehensiveness : It includes all types of visible items invisible items and capital transfer.
  4. Double entry system : Payment and receipts are accounted on the basis of double entry system.
  5. Self-balanced: Double entry system itself keeps balance of payment as balanced.
  6. Adjustment of differences : Whenever difference arises between total receipts and payments, this disequilibrium needs to be adjusted. Balance of payments is thus as overall record of all economic transactions of a country in a given period with rest of the world.

Question 25.
What is Demand ?
Answer:
Demand refers to the quantities of a commodity that the consumers are able and willing to buy at each possible price of the commodity during a given period of time.
The three elements of demand for a commodity :

  1. desire for a commodity
  2. money to fulfill that desire
  3. readiness to spend money.

Thus, demand may be defined as the desire to buy a commodity, backed by sufficient purchasing power and the willingness to spend.

Long Answer Type Questions

Question no. 26 to 33 are Long answer type questions. Answer any 4 of them. Each question carries 5 marks. (4×5 = 20)

Question 26.
Explain the different functions of money.
Answer:
The different functions of money are mainly of two types :

  1. Primary functions
  2. Secondary functions

1. Primary functions: Primary functions of money are also called prime functions. These functions are of prime importance and common to all countries during all the periods. Money has two prime functions:

  • Medium of exchange : Money acts as a
    medium of exchange.In modem days,exchange is the basis of entire economy and money makes this exchange possible.
  • Measure of Value : Money acts a unit of measure of value.The value of every commodity can be measured in money.

2. Secondary functions : These functions are supplementary to primary functions.There are following three secondary functions are as follows:

  • Standard of deferred payments : Deferred payments mean those payments which are to be made in future.
  • Store of value : Store of value can take place only when person becomes confident to use his savings as per his requirements in future.
  • Transfer of value : Money is a liquid means of exchange. Hence, purchasing power of money can easily be transferred from one person to another or one place to the other.

Question 27.
Discuss the characteristics of Perfect Competition.
Answer:
Perfect competition.is that market situation in which a large number of buyers and sellers are found for homogeneous product single buyer or the seller are not capable of affecting the prevailing price and hence in a perfect competition market, a single market price prevails for the commodity.
Features of Perfect Competition :

  1. Large number of buyers and sellers : Perfect competition market has a large number of buyers and sellers and hence any buyer or seller can not influence the market price. In other words individual buyer or seller can not influence the demand and supply conditions of the market.
  2. Homogeneous product: The units sold in the market by all sellers are homogeneous (or identical) in nature.
  3. Free entry and exit of firms : In perfect competition any new firm may join the industry or any old firm may quit the industry. Hence there is no restriction on free entry or exit of firms into/from the industry.
  4. Perfect knowledge of the market: In perfect competition every buyer has the perfect knowledge of market conditions. None of the buyers will buy the commodity at higher price than the prevailing price in the market. Hence only one price prevails in the market.
  5. Perfect mobility of factors : In perfect competition the factors of production are perfectly mobile. Factors can easily be mobile from one industry to other industry (or one firm to another firm) without any difficulty.
  6. No transportation cost : Transportation cost remains zero in perfect competition due to which one price prevails in the market.

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 28.
How does price determination in monopoly ?
Answer:
A monopolist charges, different prices from different consumers, called price discrimination. A monopolist has complete control over price and can also practice price discrimination.

Full control over price under monopoly does not mean monopolist can sell any amount of the commodity at any price. Once the monopolist fixes price of the commodity quantity demanded will entirely depend upon the buyers.

If the buyers feel that price is high, quantity demanded, will be low and vice-versa. Accordingly, there is an inverse . relationship between priede fixed by the monopolist and quantity sold by the monopoly firm or quantity demanded of the monopoly product. Thus, demand curve facing a monopoly firm is downward sloping.

Question 29.
Explain different types of Economic policy.
Answer:
Economic system : It is a structure of such institutions with which all economic activities are operated in the society. Every economy is based on an economic system which can be divided into 3 categories.

  1. Capitalist economy or Market economy
  2. Socialist economy or Planned economy
  3. Mixed economy.

1. Market economy contains the following important features :

  • Private property : Capitalist economic system recognises ‘Law of inheritance’ and right of individual private property. It also ensures to transfer the property of dead person to its heir.
  • Economic freedom : Capitalist economy grants various economic freedoms to the individual like freedom to work. Freedom of choice of consumption and saving and investment.
  • Competition : Competition is an essential features of market. Demand and supply takes places due to competition appearing in the economy.
  • Price mechanism : In this economy prices are determined by the automatic adjustment of price mechanism price in market is determined at the point where demand and supply forces become equal.

2. Socialist Economy : The salient features of this economics my all as follows :

  • Social ownership : In this economy social ownership is found on factors of production. These factors are used for the welfare of the society as a whole. Right to individual property has no place in socialist economy rather it is profited to only self-consumption goods.
  • Passive role of price mechanism : In this economy prices are not determined by price mechanism, rather government take the use of accounting prices which are determined by govt, itself on the basis of social interest.
  • Absence of competition : Socialist economy
    works on planning and direction as a result of which competition remains absent in the economy.

3. Mixed Economy : It contains the following economic features:

  • Co-existence of private and public ownership : Private and public sectors co-exist in the mixed economy. Both private ownership and profit motive are found in such economic system. Law of inheritance finds a place in the economy but government imposes progressive taxation to attain economic equality.
  • Economic freedom : Though enough state interference is found in mixed economy people enjoy limited economics freedom of choice, production investment and saving. Govt, adopts many controls so check the unlimited economic freedom of the individual.
  • Price system : Both price mechanism and profit motive determine the price system simultaneously in the
    mixed economy. Profit motive is managed by the govt. So that it may not hit the motive of social welfare.

Question 30.
Explain different process of measurement of national income.
Answer:
Measurement of national income : Three steps of value addition are as follows :
(i) First Step : Identification and classfication of productive enterprise at the very first step, we are to identify and classify various productive enterprises of an economy. Broadly, we can classify the economy into following three sectors:

  • Primary sector: It is that sector which produces goods by exploiting natural resources like land, water, forests, mines etc.
  • Secondary sector : This sector is also as manufacturing sector. It transforms one type of commodity into another, using men, machines and materials.
  • Teritory sector : This sector is also known as service sector, which provides useful services to primary and secondary sector.

(ii) Second Step: Calculation of net value of output To estimate the net value added in each identified
enterprise in step first, the following estimates are calculated:

  • Value of output,
  • Value of intermediate consumption,
  • Consumption of fixed capital i.e. depreciation. Value added + Value of Output – Intermediate consumption- Net Indirect taxes Hence, Net value Value added by Added = Primary sector + value added by secondary sector + value added by teritory sector.

(iii) Third step : Calculation of net factor income – road. The third and final step in the estimation of national income is to estimate the net factor income earned from abroad and add it to the net domestic product at factor.
This gives us the national income.
NNPFC = NDPFC + NFIA
Net National Product  Net Domestic product at factor cost = of factor cost
Or, National income + Net factor income from

Question 31.
Define different method of exchange rate?
Answer:
Exchange rate is mainly Of two types are as follows:

  1. Fixed exchange rate
  2. Flexible exchange rate

1. Fixed rate of exchange refers to that rate of exchange which is fixed by the government. It generally does not change or the changes can take place within a fixed limit only. In gold standard, exchange rate was fixed because changes in exchange rate could take place within certain limits and these limits were called ‘gold points’. Historically the two forms of fixed exchange rate were :

  • Gold standard system of exchange rate
  • Bretton woods system of exchange rate

2. Flexible exchange rate is that rate which is determined by market forces. Change in flexible exchange rate occur on account of change in market demand and supply. Flexible exchange rate is also called floating exchange rate. Thus, flexible rate is free to fluctuate according to the changes, in the demand and supply of foreign currency.
Hence, R = ∫(D, S)
i .e. Exchange rate is a function of demand and supply.

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 32.
How many types of credit controlling in central bank ?
Answer:
The two types of credit controlling in central bank are as follows :

  1. Quantitative methods
  2. Qualitative or Selective methods.

1. Quantitative Method: It refers to those methods of credit control which are used by the central bank to influence the total volume of credit without regard for the purpose for which the credit is put. Quantitaitve credit control methods are :

  • Bank rate : The bank rate is the rate of which the central bank is prepared to discount the first class bills of exchanges and grant loans of to commercial banks. This is the indirect important method for controlling credit money.
  • Open market operations : Open market operations means “purchase or sale of government and other approved securities by the central bank in money and capital market.”
  • Change in cash reserve ratio : When the cash flow or credit is to be increased, cash reserve ratio is reduced and when the cash flow or credit is to be reduced, cash reserve ratio is increased.
  • Change in statutory liquidity ratio: Every bank is required to maintain a fix percentage of its assets in the form of cash or other liquid assets, called SLR.

2. Qualitative or Selective method : Qualitative or selective methods are those methods which are used by the central bank to regulate the flow of credit into particular directions of the economy.
The important qualitative methods of credit control are :

  • Rationing of credit: Central bank is the lender of last resort. So, it can adopt the measures of credit rationing for credit control.
  • Regulation of consumer’s credit : In this method the credit given to durable consumer goods is controlled. In days of inflation, consumer’s credit is squeezed and in days of deflation, credit is expanded.
  • Change in margin requirements : Marginal requirement is the difference between the current value of physical security offered for loans and the value of loans granted. Central bank determines marginal requirement ratio for different commodities.
  • Direct Action : Central bank can take direct action against any commercial bank if the latter do not follow central banks direction.

Bihar Board 12th Economics Model Question Paper 5 in English Medium

Question 33.
Why the slope of demand curve is downward ?
Answer:
Downward slope of demand curve indicated that more is purchased in response to fall in price. It is positive when increase in income causes increase in demand. It occurs in case of normal goods. Income effect is negative when increase in income causes decreases in demand. It occurs in case of inferior, goods, thus, there is inverse relationship between price of a commodity and its quantity demanded. This may be explained in terms of the following factors :

  1. Law of diminishing marginal utility: According to this law as a consumer in a given time, increases the consumption of a commodity, the utility from each successive unit goes on diminishing. It is therefore, clear that with fall in price, more units, of a commodity will be demanded and with rise in price, less units, of a commodity will be demanded.
  2. Income effect : Income effect is the effect on the change in the quality demanded when the real income of buyer changes as a result of the change in the price of commodity alone.
  3. Substitution effect : Substitution effect refers to substitution of one commodity for the other when it becomes relatively cheaper.
  4. Size of consumer group :’When the price of a commodity fall many consumer who were not buying it at its previous price begin to purchase it.
  5. Different uses : Many goods have alternative uses grams are used for human consumption as well as for the consumption of horses