Category: Class 12

Bihar Board 12th Chemistry Objective Questions and Answers

Bihar Board 12th Chemistry Objective Answers Chapter 1 The Solid State

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

Question 2.
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

Question 3.
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 4.
Solid X is a very hard solid which is electrical insulator in solid as well as in molten state and has extremely high melting point. What type of solid is it ?
(a) Ionic solid
(b) Covalent solid
(c) Metallic solid
(d) Molecular solid
Answer:
(b) Covalent solid

Question 5.
Examples of few solids are given below. Find out the example which is not correctly matched.
(a) Ionic solids – NaCl, ZnS
(b) Covalent solids – H₂,l₂
(c) Molecular solids – H₂O_(s)
(d) Metallic solids – Cu, Sn
Answer:
(b) Covalent solids – H₂,l₂

Question 6.
Which of the following solids is the structure of CsCl crystal ?
(a) Body centred cubic
(b) Simple cubic
(c) Face centred cubic
(d) Edge centred cubic
Answer:
(a) Body centred cubic

Question 7.
Which of the following does not represent a type of crystal system ?
(a) Triclinic
(b) Monoclinic
(c) Rhombohedral
(d) Isotropical
Answer:
(d) Isotropical

Question 8.
Which of the following primitive cells show the given parameters ?
a # b # c, α = β = Y = 90°
(a) Cubic
(b) Tetragonal
(c) Orthorhombic
(d) Hexagonal
Answer:
(c) Orthorhombic

Question 9.
Which type of crystals contains more than one Bravais lattice ?
(a) Hexagonal
(b) Triclinic
(c) Rhombohedral
(d) Monoclinic
Answer:
(d) Monoclinic

Question 10.
For the structure given below the site marked as S is a ……………
(a) tetrahedral void
(b) cubic void
(c) octahedral void
(d) none of these

Answer:
(c) octahedral void

Question 11.
A metal crystallises into a lattice containing a sequence of layers as AB AB AB………………….. What percentage of voids are left in the lattice ?
(a) 72%
(b) 48%
(c) 26%
(d) 32%
Answer:
(c) 26%

Question 12.
In ccp arrangement the pattern of successive layers can be designated as …………
(a) AB AB AB
(b) ABC ABC ABC
(c) AB ABC AB
(d)  ABA ABA ABA
Answer:
(b) ABC ABC ABC

Question 13.
The coordination number of metal crystallising in a hexagonal close packing is ………
(a) 12
(b) 4
(c) 8
(d) 6
Answer:
(a) 12

Question 14.
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 15.
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 16.
A solid AB has a rock salt structure. If radius of cation A⁺ is 120 pm, what is the minimum value of radius of B⁺anion (a) 120 pm
(b) 240 pm
(c) 290 pm
(d) 360 pm
Answer:
(c) 290 pm

Question 17.
How many chloride ions are surrounding sodium ion in sodium chloride crystal ?
(a) 4
(b) 8
(c) 6
(d) 12
Answer:
(c) 6

Question 18.
In NaCl structure, ……………
(a) all octahedral and tetrahedral sites are occupied
(b) only octahedral sites are occupied
(c) only tetrahedral sites are occupied
(d) neither octahedral nor tetrahedral sites are occupied.
Answer:
(b) only octahedral sites are occupied

Question 19.
NaCl type crystal (with coordination no. 6 : 6) can be converted into CsCl type crystal (with coordination no. 8 : 8) by applying ……
(a) high temperature
(b) high pressure
(c) high temperature and high pressure
(d) low temperature and low pressure.
Answer:
(b) high pressure

Question 20.
Coordination numbers of Cs⁺ and Cl^– in CsCl crystal are ………….
(a) 8, 8
(b) 4,4
(c) 6,6
(d) 8,4
Answer:
(a) 8, 8

Question 21.
A unit cell of BaCl₂ (fluorite structure) is made up of ………..
(a) four Ba²⁺ ions and four Cl^– ions
(b) four Ba²⁺ ions and eight Cl^– ions
(c) eight Ba²⁺ ions and four Cl^– ions
(d) four Ba²⁺ ions and six Cl^–
Answer:
(c) eight Ba²⁺ ions and four Cl^– ions

Question 22.
In face centred cubic unit cell, edge length is …………..
(a) \(\frac{4}{\sqrt{3}} \mathrm{r}\)
(b) \(\frac{4}{\sqrt{2}} \mathrm{r}\)
(c) 2r
(d) \(\frac{\sqrt{3}}{2} \mathrm{r}\)
Answer:
(b) \(\frac{4}{\sqrt{2}} \mathrm{r}\)

Question 23.
The edge length of fee cell is 508 pm. If radius of cation is 110 pm, the radius of anion is …………
(a) 110 pm
(b) 220 pm
(c) 285 pm
(d) 144 pm
Answer:
(d) 144 pm

Question 24.
The edge length of sodium chloride unit cell is 564 pm. If the size of Cl^– ion is 181 pm. The size of Na⁺ ion will be …….
(a) 101 pm
(b) 181 pm
(c) 410 pm
(d) 202 pm
Answer:
(a) 101 pm

Question 25.
The radii of Na⁺ and Cl^– ions are 95 pm and 181 pm respectively. The edge length of NaCl unit cell is ………..
(a) 276 pm
(b) 138 pm
(c) 552 pm
(d) 415 pm
Answer:
(c) 552 pm

Question 26.
Copper crystallises in fee with a unit cell length of 361 pm. What is the radius of copper atom ?
(a) 157 pm
(b) 181 pm
(c) 127 pm
(d) 108 pm
Answer:
(c) 127 pm

Question 27.
Total volume of atoms present in a fee unit cell of a metal with radius r is …………
(a) \(\frac{12}{3} \pi r^{2}\)
(b) \(\frac{16}{3} \pi r^{3}\)
(c) \(\frac{20}{3} \pi r^{3}\)
(d) \(\frac{24}{3} \pi r^{3}\)
Answer:
(b) \(\frac{16}{3} \pi r^{3}\)

Question 28.
Relationship between atomic radius and the edge length a of a body-centred cubic unit cell is ……..
(a) r = a/2
(b) \(r=\sqrt{a / 2}\)
(c) \(r=\frac{\sqrt{3}}{4} a\)
(d) \(r=\frac{3 a}{2}\)
Answer:
(c) \(r=\frac{\sqrt{3}}{4} a\)

Question 29.
Edge length of a unit cell of chromium metal is 287 pm with bcc arrangement. The atomic radius is of the order
(a) 124.27 pm
(b) 287 pm
(c) 574 pm
(d) 143.5 pm
Answer:
(a) 124.27 pm

Question 30.
The fraction of the total volume occupied by the atoms present in a simple cube is ………….
(a) \(\frac{\pi}{4}\)
(b) \(\frac{\pi}{6}\)
(c) \(\frac{\pi}{3 \sqrt{2}}\)
(d) \(\frac{\pi}{4 \sqrt{2}}\)
Answer:
(b) \(\frac{\pi}{6}\)

Question 31.
A unit cell of sodium chloride has four formula units. The edge length of the unit cell is 0.564 nm. What is the density of sodium chloride ?
(a) 3.89 g cm^-3
(b) 2.16 gem^-3
(c) 3 g cm^-3
(d) 1.82 g cm^-3
Answer:
(b) 2.16 gem^-3

Question 32.
The distance between Na⁺ & Cl^– ions in NaCl with a density 3.165 g cm^-3 is …………..
(a) 497 pm
(b) 248.5 pm
(c) 234 pm
(d) 538.5 pm
Answer:
(b) 248.5 pm

Question 33.
How many lithium atoms are present in a unit cell with edge length 3.5A and density 0.53 g cm^-3 ?
(a) 2
(b) 1
(c) 4
(d) 6
Answer:
(a) 2

Question 34.
Alkali halides do not show Frenkel defect because …………….
(a) cations and anions have almost equal size
(b) there is a large difference in size of cations and anions
(c) cations and anions have low coordination number
(d) anions cannot be accommodated in voids.
Answer:
(a) cations and anions have almost equal size

Question 35.
Which of the following crystals does not exhibit Frenkel defect ?
(a) AgBr
(b) AgCl
(c) KBr
(d) ZnS
Answer:
(c) KBr

Question 36.
What type of stoichiometric defect is shown by ZnS ?
(a) Schottky defect
(b) Frenkel defect
(c) Both Frenkel and Schottky defects
(d) Non-stoichiometric defect
Answer:
(b) Frenkel defect

Question 37.
In a Schottky defect, …………..
(a) an ion moves to interstitial position between the lattice points
(b) electrons are trapped in a lattice site
(c) some lattice sites are vacant
(d) some extra cations are present in interstitial spaces.
Answer:
(c) some lattice sites are vacant

Question 38.
Silver halides generally show ………….
(a) Schottky defect
(b) Frenkel defect
(c) both Frenkel and Schottky defects
(d) cation excess defect.
Answer:
(c) both Frenkel and Schottky defects

Question 39.
An electron trapped in an anion site in a crystal is called ………….
(a) F-centre
(b) Frenkel defect
(c) Schottky defect
(d) interstitial defect
Answer:
(a) F-centre

Question 40.
Which of the following will have metal deficiency defect ?
(a) NaCl
(b) FeO
(c) KCl
(d) ZnO
Answer:
(b) FeO

Question 41.
Pure silicon and germanium behave as …………
(a) conductors
(b) semiconductors
(c) insulators
(d) piezoelectric crystals
Answer:
(c) insulators

Question 42.
To get n-type of semiconductor, germanium should be doped with ………….
(a) gallium
(b) arsenic
(c) aluminium
(d) boron
Answer:
(b) arsenic

Question 43.
p-type semiconductors are formed when Si or Ge are doped with …………
(a) group 14 elements
(b) group 15 elements
(c) group 13 elements
(d) group 18 elements.
Answer:
(c) group 13 elements

Question 44.
Paramagnetic substances are magnetised in a magnetic field in the same direction. Paramagnetism is due to the presence of……………….
(a) one or more unpaired electrons
(b) all paired electrons
(c) permanent spin and orbital motion
(d) parallel and anti-parallel spins in equal numbers.
Answer:
(a) one or more unpaired electrons

Question 45.
Fe₃O₄ is ferrimagnetic at room temperature but at 850 K, it becomes
(a) diamagnetic
(b) ferrimagnetic
(c) paramagnetic
(d) anti-ferromagnetic
Answer:
(c) paramagnetic

Question 46.
Which of the following metal oxides is antiferromagnetic in nature ?
(a) MnO₂
(b) TiO₂
(c) NO₂
(d) CrO₂
Answer:
(a) MnO₂

Question 47.
Which of the following conditions favours the existance of a substance in the solid state ?
(a) High temperature
(b) Low temperature
(c) High thermal energy
(d) Weak cohesive forces
Answer:
(b) Low temperature

Question 48.
Which of the following is an amorphous solid ?
(a) Graphite (c)
(b) Quartz glass (SiO₂)
(c) Chrome alum
(d) Silicon carbide (SiC)
Answer:
(b) Quartz glass (SiO₂)

Question 49.
Iodine molecules are held in the crystals lattice by
(a) London forces
(b) dipole-dipole interactions
(c) covalent bonds
(d) coulombic forces
Answer:
(a) London forces

Question 50.
Which of the following is a network solid ?
(a) SO_2(Solid)
(b) I₂
(c) Diamond
(d) H₂O_(Ice)
Answer:
(c) Diamond

Question 51.
Graphite is a good conductor of electricity due to the presence of_______
(a) lone pair of electrons
(b) free valence electrons
(c) cations
(d) anions
Answer:
(b) free valence electrons

Question 52.
Which of the following oxides behaves as conductor or insulator depending upon temperature ?
(a) TiO
(b) SiO₂
(c) TiO₃
(d) MgO
Answer:
(c) TiO₃

Question 53.
Which of the following oxides shows electrical properties like metals ?
(a) SiO₂
(b) MgO
(c) SO_2(s)
(d) CrO₂
Answer:
(d) CrO₂

Question 54.
The lattice site in a pure crystal cannot be occupied by
(a) molecule
(b) ion
(c) electron
(d) atom
Answer:
(c) electron

Question 55.
Graphite cannot be classified as_____________ .
(a) conducting solid
(b) network solid
(c) covalent solid
(d) ionic solid
Answer:
(d) ionic solid

Question 56.
Cations are present in the interstitial sites in___________
(a) Frenkel defect
(b) Schottky defect
(c) vacancy defect
(d) metal deficiency defect
Answer:
(a) Frenkel defect

Question 57.
Which of the following is true about the charge acquired by p-type semiconductors ?
(a) positive
(b) neutral
(c) negative
(d) depends on concentration of p impurity
Answer:
(b) neutral

Question 58.
In which pair most efficient packing is present ?
(a) hep and bcc
(b) hep and ccp
(c) bcc and ccp
(d) bcc and simple cubic cell
Answer:
(c) bcc and ccp

Question 59.
What is the coordination number in a square close packed structure in two dimensions ?
(a) 2
(b) 3
(c) 4
(d) 6
Answer:
(c) 4

Question 60.
Which kind of defects are introduced by doping ?
(a) Dislocation defects
(b) Schottky defects
(c) Frenkel defects
(d) Electronic defects
Answer:
(d) Electronic defects

Question 61.
The edge lengths of the unit cells in terms of the radius of spheres constituting fee, bcc and simple cube unit cell are respectively.
(a) \(2 \sqrt{2} r, \frac{4 r}{\sqrt{3}}, 2 r\)
(b) \(\frac{4 r}{\sqrt{3}}, 2 \sqrt{2} r, 2 r\)
(c) \(2 \mathrm{r}, 2 \sqrt{2} \mathrm{r}, \frac{4 \mathrm{r}}{\sqrt{3}}\)
(d) \(2 \mathrm{r}, \frac{4 \mathrm{r}}{\sqrt{3}}, 2 \sqrt{2} \mathrm{r}\)
Answer:
(a) \(2 \sqrt{2} r, \frac{4 r}{\sqrt{3}}, 2 r\)

Bihar Board 12th Biology Model Papers

Bihar Board 12th Biology Model Question Paper 4 in English Medium

Time : 3 Hours 15 Min
Total 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 indicate full marks.
3. While answering the questions, the candidate should adhere to the word limit as for 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 result will be treated as invalid.
7. In Section – B, there are Non-objective type questions. There are 18 Short answer type questions, out of which any 10 questions are to be answered. Each question carries 2 marks. Apart from this, there are 6 long answer type questions, out of which any 3 of them are to be answered. Each question carries 5 marks
8. Use of any electronic device is prohibited.

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.
Mendel worked on
(a) Garden pea
(b) Chick pea
(c) Grass pea
(d) None of these
Answer:
(a) Garden pea

Question 2.
Thymus is present near
(a) Heart
(b) Kidney
(c) Liver
(d) Testis
Answer:
(a) Heart

Question 3.
Which among the following antibodies, the Nascent child Obtains maximum from mother’s milk.
(a) Ig A
(b) Ig M
(c) Ig B
(d) Ig E
Answer:
(a) Ig A

Question 4.
10% law for energy transfer in a food chain is given by
(a) Tansley
(b) Weismann
(c) Lindmann
(d) None of the above
Answer:
(c) Lindmann

Question 5.
Causative agent of Dengue fever is
(a) Virus
(b) Bacteria
(c) Protozoa
(d) All of the above
Answer:
(a) Virus

Question 6.
New plants develop from leaves in
(a) Cycas
(b) Eichhornia
(c) Bryophyllum
(d) None of the above
Answer:
(c) Bryophyllum

Question 7.
Phosphorus is important constituent of
(a) Plasma membrane
(b) Nucleic Acid
(c) Cellular energy transport system
(d) All of the above
Answer:
(d) All of the above

Question 8.
Which of the following disease is spread by Protozoan parasite?
(a) Malaria
(b) Kala-azar
(c) Amoebiasis
(d) All of the above
Answer:
(d) All of the above

Question 9.
Fingcrlings and larvae of
(a) Silkworm
(b) Honey bee
(c) Fish
(d) All of the above
Answer:
(c) Fish

Question 10.
Inducer molecule in lac operon of E. Coli is chemically.
(a) Amino acid
(b) Disaccharides
(c) Protein
(d) All of the above
Answer:
(b) Disaccharides

Question 11.
In a natural Ecosystem decomposition takes place by
(a) Parasitic Algae
(b) Virus
(c) Bacteria and Fungi
(d) All of the above
Answer:
(c) Bacteria and Fungi

Question 12.
PCR technique is routinely used to detect
(a) Cancer
(b) T.B.
(c) HIV
(d) All of the above
Answer:
(c) HIV

Question 13.
Production of fruit without fertilization is known as
(a) Apomixis
(b) Apogamy
(c) Parthenogenesis
(d) None of the above
Answer:
(c) Parthenogenesis

Question 14.
Chiasma formation occurs during
(a) Amitosis
(b) Mitosis
(c) Meiosis
(d) None of the above
Answer:
(c) Meiosis

Question 15.
Acrosome is a part of
(a) Spermatozoa
(b) RNA
(c) DNA
(d) All of the above
Answer:
(a) Spermatozoa

Question 16.
Biogas contains
(a) H₂S
(b) CH₄
(c) CO₂
(d) All of the above
Answer:
(b) CH₄

Question 17.
How many structural genes are present in lac- operon in E. coli?
(a) 4
(b) 2
(c) 3
(d) None of the above
Answer:
(c) 3

Question 18.
Ozone layer is found in
(a) Troposphere
(b) Stratosphere
(c) Mesosphere
(d) Exosphere
Answer:
(b) Stratosphere

Question 19.
Mendel’s Monohybrid ratio is
(a) 1 : 2
(b) 3 : 1
(c) 9 : 3 : 3 : 1
(d) All of the above
Answer:
(b) 3 : 1

Question 20.
Ta jmahal located in Agra is in danger due to which gas?
(a) CO₂
(b) NO₂
(c) SO₂
(d) CFC
Answer:
(c) SO₂

Question 21.
Which is used to see DNA in laboratory?
(a) Aniline
(b) Carmine
(c) Ithidium Bromide
(d) All of the above
Answer:
(c) Ithidium Bromide

Question 22.
Pyramid of energy is always
(a) Upright
(b) Downward
(c) Both
(d) None of the above
Answer:
(a) Upright

Question 23.
An organism with two identical alleles is said to be
(a) Homozygous
(b) Heterozygous
(c) Dominant
(d) Hybrid
Answer:
(a) Homozygous

Question 24.
Bacteriophase kills
(a) Fungi
(b) Parasites
(c) Bacteria
(d) Viruses
Answer:
(c) Bacteria

Question 25.
Which of the following is used in ELISA test?
(a) Endonuclease
(b) Polymerase
(c) Ligase
(d) Peroxydase
Answer:
(d) Peroxydase

Question 26.
Catla fish is found in
(a) Fresh water
(b) Hard water
(c) Both a and b
(d) None of the above
Answer:
(a) Fresh water

Question 27.
Which of the following fixes nitrogen in Symbiotic association?
(a) Chana
(b) Volvox
(c) Rhizobium
(d) None of the above
Answer:
(c) Rhizobium

Question 28.
Which on of the following is active in treatment of sewage?
(a) Fishes
(b) Fish
(c) Bacteria
(d) All of the above
Answer:
(c) Bacteria

Question 29.
Smoking causes
(a) Asthama
(b) Bronchitis
(c) Lung disease
(d) All of the above
Answer:
(d) All of the above

Question 30.
Which of the following study is called Oncology?
(a) Leprosy
(b) Cholera
(c) Cancer
(d) All of the above
Answer:
(c) Cancer

Question 31.
Elephantiasis is called as
(a) Malaria
(b) Filaria
(c) Kala-azar
(d) All of the above
Answer:
(b) Filaria

Question 32.
Which of the following causes Ozone hole?
(a) Ethylene
(b) Acetylene
(c) Chloro-florp carbon
(d) All of the above
Answer:
(c) Chloro-florp carbon

Question 33.
The process of producing immunity in the body is called
(a) Immunity
(b) Immunization
(c) Allergy
(d) All of the above
Answer:
(b) Immunization

Question 34.
Which of the following is the copper releasing IUD
(a) Lippes loop
(b) Progestasert
(c) LNG 20
(d) CUT
Answer:
(d) CUT

Question 35.
Chiasma formation occurs during
(a) Amitosis
(b) Mitosis
(c) Meiosis
(d) None of the above
Answer:
(c) Meiosis

Non-Objective Type Questions

Short Answer Type Questions

In this section, there are 18 short answer type question (each carryies 2 marks) out of which answers any ten (10) questions. (10 x 2 = 20)

Question 1.
What is Bt cotton?
Answer:
Bt cotton-Bt cotton is a type of toxin, which is obtained from Bacillus thuringiensis. It is called Bt in short form. Bt toxin gene has been cloned from the bacteria and expressed in plants to provide resistance from insects without the requirement of insecticide. Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into the several crop plants such as cotton.

Question 2.
What measures should be opted to prevent from contracting sexually transmitted diseases ?
Answer:
For prevention of sexually transmitted diseases following actions should be opted :

• Avoid sex with unknown partner/multiple partners.
• Always use condoms during coitus.
• In case of doubt, should go to a qualified doctor for early detection and get complete treatment if diagnosed with disease.

Question 3.
Write short notes on Golden rice.
Answer:
Golden rice is a genetically modified variety of rice. It contains the transgenes from the daffodil plants and also from some bacteria which are responsible for the synthesis of (3-carotene which is a component of Vitamin A. Deficiency of vitamin A causes blindness. Therefore, P-carotene present in golden variety of rice can be helpful in preventing the child blindness.

Question 4.
Describe the disease transmitted through blood transfusion.
Answer:
AIDS is a blood-transfusion transmitted disease caused by Human Immuno deficiency Virus (HIV) in which the natural immune system of the body is destroyed and body is infected with various pathogens.

Question 5.
What is tumor ?
Answer:
When cancerous cells by their division from a storage of cells, it is called tumor. Tumor are of two types –
1. Benign, 2. Malignant.

• Benign Tumor – They are restricted to a limited portion and do not extend in other parts of the body.
• Malignant – They can easily spread to different parts of the body and their cells are known as Neoplastic cells.

Question 6.
(i) What is noise pollution ? What are its various sources ?
(ii) What are its effects on human beings ?
(iii) Give some methods to control noise pollution.
Answer:
(i) Noise Pollution : It is the unwanted sound which is dumped into the atmosphere and it interferes with human communication, comfort and health.
Sources : Vehicles, musical horns, machines, transistors, radio, drum, beats of religious processions, amplified rock music and disco etc.

Question 7.
Why we say energy flow in the biosphere is unidirectional?
Answer:
The main source of energy of biosphere is ‘Sun’. During photosynthesis solar energy is converted into the chemical energy in the plants. Plants are consumed by herbivores and chemical energy of plants is partially transferred to herbivores animals. Carnivores consume herbivorous animals, their chemical energy of herbivores is transferred to carnivores. That is why, we can say that flow of energy in the biosphere is unidirectional.

Question 8.
Enumerate the major criterias for self-pollination.
Answer:
In which there is transfer of pollen grains from anther to stigma of same flower or another flower of same plants.

• It is found in bisexual plants only.
• It may occur in Cleistogamous flowers.
• There is no need of pollinating agent in it.

Question 9.
Differentiate between DNA and RNA.
Answer:

DNA	RNA
1. DNA is a genetic	1. It is not a genetic material, exception Virus.
2. De-oxyribose sugar is present.	2. Ribose sugar present.
3. Pyrimidine base thymine is present.	3. Uracil in place of thymine.
4. It is double helical	4. It is a single helical structure.

Question 10.
Describe the post-fertilization changes in a flower.
Answer:
During fertilization, the pollen tube reaches into the ovule through the micropyle. One of the two gametes, one joins with the egg cell resulting in the production of zygote. This is called syngamy and other with the two polar nuclei producing triploid primary endosperm nucleus. This is called as triple fusion. This completes the process of fertilization. After fertilization, the ovule converts into the seed and the whole ovary develops into a complete fruit. The ovary wall forms.

Question 11.
Write principles of Biotechnology.
Answer:
Principles of Biotechnology :
Biotechnology is based on two main techniques
(i) Genetic engineering-It is the science of manipulation of genes. In a strict sense it involves alterations in the chemistry of genetic material, introduction of the same into host and thereby changing the phenotype of host.

(ii) Biochemical engineering processes devoted for the growth of desired microbe or eukaryotic cell in large quantities in a culture medium in aseptic conditions for the manufacture and multiplication of biotechnological products, such as antibiotics, vaccines, enzymes etc.

Question 12.
Differentiate between Innate and Acquired Immunity?
Answer:
Innate immunity is a kind of non-specific protection of the body which persist from the birth whereas acquired immunity is pathogen-specific in which primary and secondary responses occur which depend upon memory of the primary responses.

Question 13.
Name the hormones invovled in regulation of spermatogenesis.
Answer:
The hormones involved in the regulation of spermatogenesis one follicle stimulating hormones (F.S.H.) and Lutenizing stimulating hormones (L.S.H.) which are secreted by pituitory gland under the influence of gondotropin releasing hormones from the hypothalamus.

Question 14.
Describe about Parthenium Weed.
Answer:
Parthenium is a genus of North American shrubs. Parthenium invades disturbed land including roadsides. It infests pastures and form land causing after disastrous loss of yield. As an invader it first appeared as a contaminant in imported wheat. The plant produces Allelopathic chemical that suppress crop and pasture plants and allergens that affect humans and livestock. It also causes pollen allergies. But, it may be used as a remedy of skin inflammation, diarrhoea, dysentery and malaria etc.

Question 15.
What is Tranquilizers? Explain it with examples.
Answer:
Drugs which are used in patients having mental tension & worries are called tranquilizers.
For example :

• Benzodiazepins-Used in case of mental patient and gives mental peace to them.
• Phenothiazines-It stimulate the patient and gives mental peace through eradicating mental worriness.
• Reserpine-It is obtained from Rauvolfia serpentina and very effective in mental tension and worriness.

Question 16.
List few important uses of Human Genome Project.
Answer:
(i) The genetic make up of an organism or an individual lies in the DNA sequence. The knowledge about the effect of DNA variations among individuals can lead to revolutionary new ways to diagnose, treat and prevent thousands of disorders that affect human beings.

(ii) The learning about non-human organisms, DNA sequences can lead to understanding of their natural capabilities that can be applied towards solving challenges in health care, agriculture and energy production etc.

Question 17.
Draw a labelled diagram of human male reproductive system.
Answer:

Question 18.
Describe the structure of biogas plant. Give various steps involved in obtaining biogas.
Answer:
Biogas plants consists of a concrete tank (10-15 feet deep) in which bio-wastes are collected and a slurry of dung is fed. A floating cover is placed over the slurry which keeps on rising as the gas is produced. The biogas plant has an outlet for supply of biogas and another outlet for removing slurry.
Steps :

1. Slurry of animal dung (dung + water) is fed into the digester.
2. In the digester, microbes break down or decompose the complex compounds of the biomass in the slurry.
3. Thd anaerobic microbes do not require oxygen, so the digesters are designed like a sealed chamber.
4. The process takes a few days and gases like methane, CO₂, hydrogen and hydrogen sulphide are produced.

Long Answer Type Questions

There are 6 long answers type question (each carrying 05 marks) out of which answers any three questions. (5 x 3 = 15)

Question 19.
What is pollination? Give an account of the varied means of cross-pollination in plants.
Answer:
Transfer of pollen grains after sheding from the anther to the stigma of the carpel is called pollination.
Pollination in flowering plants occurs by two methods:

• Self Pollination and
• Cross-Pollination.

(1) Self Pollination – Self pollination involves the transfer of pollen grains from the anther of the flower to the stigma of the same flower or another flower of the same plant.

(2) Cross Pollination – Cross pollination involves the transfer of pollen grains from the flower of one plant to the stigma of the flower of another plant.

Varied means of cross pollination in plants are:

(a) Dicliny – Cross-pollination always occurs when the plants are unisexual and dioecious. Ex-Papaya.
(b) Self Sterility – When the stigma of the gynoecium of a flower is not pollinated by pollen grains of the same flower. Ex-Pea, Potato etc.
(c) Dichogamy – When maturity of male and female parts of a bisexual flower occurs in different times. It is of two types : (i) Protogyny (when gynoecium matures first. Ex-Banyan) and (ii) Protandry (when androecium matures first. Ex:-Maize)
(d) Herkogamy – In some flowers physical barrier present between anther and stigma which avoid self-pollination. Ex-Calotropis
(e) Heterostyly – The flowers of some plants have different lengths of stamens and styles so their self-pollination is not possible. Ex-Primula, Oxalis etc.

Question 20.
What is adaptation? Describe the different types of adaptation in plants of deserts.
Answer:
Adaptation is an attribute of the organism to survive and reproduce in its habitat. Many adaptations have evolved over a long evolutionary time and are genetically fixed. It is of two types-temporary and permanent, e.g. Shrinking of pupil due to bright light is temporary adaptation while change of fore-limbs in feathers for fly in birds is permanant adaptation.

Following adaptations are found in plants of deserts

(a) Its roots are long, thick and goes deep in the soil.
(b) Its stems are fleshy and thick for storage of water.
(c) To check loss of water due to vapourisation, stems are generally cuticulised and fill with dense hairs.
(d) Leaves are changed into small scales and spines, which decreases loss of water due to vapourisation. .
(e) Leaves have suitable tissues for storage of water.
(f) Stomata are embedded in stomatal cavity.
Example of Xerophytic plants are-Opuntia, Euphorbia, Argemone, etc.

Question 21.
Describe the properties of genetic code.
Answer:
The properties of genetic code are as follows :
(a) Triplet nature – The genetic code is a triplet code which is arranged in a sequence on m-RNA.
(b) Unambiguous and Specific-One codon codes for only one amino acid, hence it is unambiguous and specific.
(c) Degenerate code – Some amino acids are coded by more than one codon, hence the code is degenerate.
(d) Commaless form – There are no comma and punctuation marks between the coding triplets (Codons).
(e) Universal – The code is nearly universal. For example, from bacteria to human UUU would code for Phenylalanine (Phe).
(f) Nonsense or Terminator Codon – Three of the 64 codons, namely UAA, UAG and UGA, do not specify any amino acids, but signals the end of the message.
(g) Initiation codon – AUG and sometime GUG are the initiator codon. As AUG stands for methionine, polypeptide chain begins with methionine when they are synthesized.

Question 22.
Define Biodiversity. Describe in brief any three important components of Biodiversity.
Answer:
Biodiversity is the variation of life at all levels of biological organization. In other words variability found in different forms of life like plants, animals and microorganisms and in their genes are called as biodiversity. It voluntarily integrates terresterial, aquatic and ecosystem diversity.

There are three basic components of biodiversity :-

• Genetic diversity
• Species diversity
• Ecological diversity.

(d) Genetic diversity-Genetic diversity is related to the variations of genes within species. A single species might show high diversity at the genetic level over its distributional range. For example, genetic variations shown by the medicinal plant Rauwolfia vomitoria growing in different Himalayan ranges might be in terms of the potency and concentration of the active chemical (reserpine) that the plant produces. India has more than 50,000 genetically different strains of rice and 1,000 varieties of mango.

(e) Species diversity-The diversity at the species level is called species diversity. For example, the Westerm Ghats have a greater amphibian species diversity than Eastern Ghats. Similarly, taking example of plants, Brinjal {Solatium melanogena) Potato (Solarium tuberosum) and Tomato (Solatium lycopersicon) belong to the same genus Solatium but they all too differ at the species level.

(f) Ecological diversity-The diversity at the ecosystem level is called ecological diversity. It is related to the different types of ecosystems, e.g., terrestrial (deserts, rain forest, grass land, etc.) and aquatic (rivers, ponds, lakes, sea, etc.) ecosystems.

Ecological diversity is of three types-Alpha (α), Beta (β) and Gamma (γ) diversity.

(i) Alpha diversity – It refers to the diversity of those organism which belongs to same community and habitat.

(ii) Beta diversity – Diversity between different communities of same habitat is called Beta diversity. If there is more heterogeneity in the habitats in a region or more dissimilarity between communities, there will be more Beta diversity.

(iii) Gamma diversity – Diversity at landscape level is called Gamma diversity. It envolves both types of diversity- alpha and beta. It refers to the diversity of the habitats in the whole geographical region.

Question 23.
How microbes are essential for human welfare? Explain it in detail.
Answer:
Microbes are essential for human welfare because they help through various ways in promotion of our health, foods, agro products and reduction of pollution level as well. These are illustrated below

(a) Microbes are essential for production of dairy products like paneer, curd, butter etc. which are processing products of milk. Production is carried out by the microbes such as bacteria. Similarly bread, idli, vinegar are produced by the activity of microbes.

(b) By using Mithanogen bacteria, production of biogas is possible.

(c) Microbes also help us in the treatment of domestic waste water.

(d) In the field of industries, by activity of microbes, we obtain alcoholic drinks of ionous type, organic acids, vitamin B₂, and B₁₂, dextrins, steroid, amino acids, cyclosporin etc. which all enhances our life.

(e) Microbes are used in the field of treatment against infectious diseases.

(f) In the field of agriculture, microbes are used to increase production of agriculture. We uses microbes as pesticides, weedicides which improve our environmental health.

(g) Microbes are also used as ‘single cell protein’ which fulfills our protein requirements.

Question 24.
Give an account of molecular diagnosis.
Answer:
For effective treatment of a disease, early diagnosis and understanding its pathophysiology is very important. Using conventional method of diagnosis (serum and urine analysis), early detection is not possible. Recombinant DNA technology, polymerase chain reaction (PCR) and Enzyme linked Immuno Sorbent Assay (ELISA) are some of the techniques that serves the purpose of early diagnosis.

Very low concentration of pathogen (bacteria, viruses) can be detected in early stage by application of their nucleic acid by PCR. PCR is now routinely used to detect HIV in suspected AIDS patients. It is being used to detect mutations in genes in suspected cancer patients too. It is powerful technique to identify many other genetic disorder.

ELISA is based on the principle of antigen-antibody interaction. Infection by pathogen can be detected by the presence of antigens (proteins, glyco-proteins) or by detecting the antibodies synthesised against the pathogens. Hybridoma technology is also used to produce monoclonal antibody to detect microscopic pathogens.

Bihar Board 12th Economics Model Papers

Bihar Board 12th Economics Model Question Paper 2 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. Youhave to mark, your selected option, on the OMR-Sheet. Each questiion carries 1 (one) mark. [50 x 1 = 50]

Question 1.
The subject matter of economics is being studied under which branches :
(a) Micro Economics
(b) Macro Economics
(c) Above two
(d) None of the above
Answer:
(c) Above two

Question 2.
On the basis of the ownership of the resources, economies are ?
(a) Centrally planned economy
(b) Market economy
(c) Mixed economy
(d) All of above
Answer:
(c) Mixed economy

Question 3.
Which are the central problems of an economy ?
(a) Allocation of resources
(b) Best use of resources
(c) Economic development
(d) All the above
Answer:
(d) All the above

Question 4.
Macro Economics studies :
(a) Full employment
(b) Aggregate price level
(c) Gross National Product
(d) All the above
Answer:
(d) All the above

Question 5.
This is required for a budget set:
(a) Collection of bundles
(b) Prevailing market price
(c) Total income of the consumer
(d) All the above
Answer:
(d) All the above

Question 6.
In diminishing rate of substitution :
(a) more of goods 1
(b) less of goods 2
(c) more of both 1 and 2
(d) (a) and (b) both
Answer:
(c) more of both 1 and 2

Question 7.
Consumer behaviour is studied in :
(a) Micro Economics
(b) Macro Economics
(c) Income theory
(d) None of the above
Answer:
(b) Macro Economics

Question 9.
Indifference curve is :
(a) Concave to the origin
(b) Convex to the origin
(c) Both the above true
(d) Both the above false
Answer:
(c) Both the above true

Question 10.
The slope of the demand curve is :
(a) left to right downward
(b) left to right upward
(c) parallel to x-axis
(d) none of the above
Answer:
(c) parallel to x-axis

Question 11.
Demand function is expressed by which equation ?
(a) Px
(b) Dx = Px
(c) Dx = ∫(Px)
(d) None of the above
Answer:
(d) None of the above

Question 12.
Short run production function is explained by which law ?
(a) By the law of demand
(b) By law of variable proportions
(c) By law of returns to scale
(d) By elasticity of demand
Answer:
(a) By the law of demand

Question 13.
Tick the correct in the following :
(a) TVC = TC – TFC
(b) TC = TVC – TFC
(c) TFC = TVC + TC
(d) TC = TVC × TFC
Answer:
(b) TC = TVC – TFC

Question 14.
MR is expressed as :
(a) \(\frac { ΔTR }{ ΔQ }\)
(b) \(\frac { TR }{ Q }\)
(c) \(\frac { ΔAR }{ Q }\)
(d) None of the above
Answer:
(a) \(\frac { ΔTR }{ ΔQ }\)

Question 15.
In monopoly and monopolistic condition :
(a) AR = MR
(b) AR > MR
(c) AR < MR
(d) None of the above
Answer:
(a) AR = MR

Question 16.
In every market situation which condition is necessary to be fulfilled for a firm’s equilibrium ?
(a) AR = MC
(b) MR = MC
(c) MC curve should cut the MR curve from below
(d) (b) and (c) both
Answer:
(d) (b) and (c) both

Question 17.
Which of the following statement is true ?
(a) There is direct relationship between the price of a commodity and its Supply
(b) Supply curve moves left to right upward
(c) Supply is affected by many factors
(d) All the above
Answer:
(d) All the above

Question 18.
If the price of a commodity rises by 40% but the supply increases by only 15%, supply of such commodity would be :
(a) Excessive elastic
(b) Elastic
(c) Inelastic
(d) completely inelastic
Answer:
(d) completely inelastic

Question 19.
In equilibrium position :
(a) The amount to be sold is equal to the amount to be purchased.
(b) Market supply is equal to market demand
(c) Neither the firm nor the consumer wants to be destabilised
(d) All the above
Answer:
(d) All the above

Question 20.
Every firm uses labour up to the point:
(a) Where labour’s marginal productivity is equal to the wage rate
(b) Where labour’s marginal productivity is less than the wage rate
(c) Where labor r’s marginal productivity is more than the wage rate
(d) None of the above
Answer:
(a) Where labour’s marginal productivity is equal to the wage rate

Question 21.
In which market product differentiation is found ?
(a) Pure competition
(b) Perfect competition
(c) Monopoly
(d) Monopolistic competition
Answer:
(c) Monopoly

Question 22.
Government decides “price ceiling”
(a) On necessary goods
(b) Which is less than the price decided by market ?
(c) To make it affordable to the common man
(d) All of the above
Answer:
(d) All of the above

Question 23.
Price is determined at the point, where :
(a) Demand of the commodity is high
(b) Supply of the commodity is high
(c) Demand of the commodity and supply of the commodity is equal
(d) None of the above
Answer:
(c) Demand of the commodity and supply of the commodity is equal

Question 24.
Market price is found in :
(a) Short period market
(b) Long period market
(c) Very long period market
(d) None of the above
Answer:
(a) Short period market

Question 25.
British economist John Maynard Keynes famous book “The General Theory” was published in which year :
(a) 1926
(b) 1936
(c) 1946
(d)1956
Answer:
(c) 1946

Question 26.
The great Depression came in which year :
(a) 1949
(b)1939
(c) 1929
(d) 19194
Answer:
(a) 1949

Question 27.
Macro economics sees an economy as a combination of which sectors :
(a) Family
(a) Firm
(c) Government and external sector
(d) All of above
Answer:
(d) All of above

Question 28.
GNPMP = ?
(a) GDPMP – Depreciation
(b) GDPMP + net factor income from abroad
(c) Both the above
(d) None of the above
Answer:
(d) None of the above

Question 29.
Which is the correct sequence of money’s development ?
(a) Commodity money, Paper money, Metal money
(b) Commodity money, Metal money, Paper money
(c) Credit money, Metal money, Paper money
(d) None of the above
Answer:
(a) Commodity money, Paper money, Metal money

Question 30.
Reserve Bank of India has presented four measures of money supply, namely M1, M2, M3 and M4, M1 includes :
(a) C = currency held by public
(b) DD = net demand deposit of the bank
(c) OD = other deposits held with the RBI
(d) All of the above
Answer:
(a) C = currency held by public

Question 31.
Which is common man’s bank ?
(a) Commercial Bank
(b) Central Bank
(c) (a) and (b) both
(d) None of the above
Answer:
(c) (a) and (b) both

Question 32.
(a) \(\frac { 1 }{ CRR }\)
(b) Cash × \(\frac { 1 }{ CRR }\)
(c) Cash × CRR
(d) None of these above
Answer:
(c) Cash × CRR

Question 33.
Which of the following is Central Bank’s function ?
(a) Right of issuing notes
(b) Government’s banker
(c) Custodian of Foreign Exchange Reserves
(d) All of the above
Answer:
(d) All of the above

Question 34.
Which currency is issued by Central Bank of the country ?
(a) Money in circulation
(b) Credit money
(c) Coins
(d) All of the above
Answer:
(a) Money in circulation

Question 35.
In an open economy which are the components of Aggregate Demand :
(a) Consumption
(b) Investment
(c) Consumption + government expenditure
(d) Consumption + Investment + Govt, expenditure + net export
Answer:
(d) Consumption + Investment + Govt, expenditure + net export

Question 36.
APC + APS = ?
(a) 0
(b) 1
(c) Infinity
(d) None of the above
Answer:
(c) Infinity

Question 37.
What are the reasons of excess demand ?
(a) Increase in public expenditure
(b) Increase in money supply
(c) Decrease in taxes
(d) All the above
Answer:
(d) All the above

Question 38.
Indian’s financial year is :
(a) 1st April to 31st March
(b) 1st January to 31st March
(c) 1st July to 30th June
(d) None of the above
Answer:
(a) 1st April to 31st March

Question 39.
In direct taxes which one of the following is included ?
(a) Income Tax
(b) Gift Tax
(c) (a) and (b) both
(d) None of the above
Answer:
(c) (a) and (b) both

Question 40.
In India who issues one rupee note;
(a) Reserve Bank of India
(b) Finance Ministry of govt, of India
(c) State Bank of India
(d) None of the above
Answer:
(b) Finance Ministry of govt, of India

Question 41.
Capital Budget includes:
(a) Revenue receipts and revenue expenditure
(b) Capital receipts and capital expenditure
(c) Direct and Indirect taxes
(d) None of the above
Answer:
(b) Capital receipts and capital expenditure

Question 42.
Primary deficit is :
(a) Fiscal Deficit – Interest Payment
(b) Fiscal Deficit + Interest Payment
(c) (a) and (b) both
(d) None of the above
Answer:
(a) Fiscal Deficit – Interest Payment

Question 43.
Budgets are of the following types :
(a) Balanced Budget
(b) Surplus Budget
(c) Deficit Budget
(d) All the above
Answer:
(d) All the above

Question 44.
Exchange rate is of the following types :
(a) Fixed exchange rate
(b) Flexible echange rate
(c) (a) and (b) both
(d) None of the above
Answer:
(c) (a) and (b) both

Question 45.
During Bretton Woods System most countries had:
(a) Fixed Exchange Rate
(b) Pegged Exchange rate
(c) (a) and (b) both
(d) None of the above
Answer:
(c) (a) and (b) both

Question 46.
Fixed exchange rate has following merits :
(a) Promotes Capital movtinem
(b) Prevents capital outflow
(c) Prevents speculation
(d) All the above
Answer:
(d) All the above

Question 47.
Bretton Woods Conference of 1944 established :
(a) International Monetary Fund
(b) World Bank
(c) (a) and (b) both
(d) None of the above
Answer:
(a) International Monetary Fund

Question 48.
Demerits of flexible exchange rate are :.
(a) Instability and uncertainty
(b) Encourages speculation
(c) Discourage international trade and investment
(d) All of the above
Answer:
(d) All of the above

Question 49.
Balance of Trade = ?
(a) Export of visible items – Import of visible item
(b) Export if visible and invisible items – Import of visible and invisible items
(c) Import of visible items – Export of visible items
(d) None of these
Answer:
(b) Export if visible and invisible items – Import of visible and invisible items

Question 50.
Components of Balance of Payments is :
(a) Current Account
(b) Capital Account
(c) (a) and (b) both
(d) None of the above
Answer:
(c) (a) and (b) both

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.
What do you mean by consumer’s equilibrium ? State its assumptions.
Answer:
The state of balance achieved by an end user of products that refers to the amount of goods and services they can purchase given their present level of income and the current level of prices. Consumer equilibrium allows a consumer to obtain the most satisfaction possible from their income.
Assumptions of consumer’s equilibrium :

1. His money income is given and constant
2. There is no change in the habits and tastes of the consumer throughout the analysis.

Question 2.
Write the meaning of perfectly elastic demand and perfectly inelastic demand.
Answer:
Perfectly elastic demand : It means at a higher price, quantity demanded decrease to zero, and perfectly inelastic demand. It means a change in price has no effect on quantity demanded.

Question 3.
State the relation between Marginal Production and Average Production.
Answer:
Marginal production and average production curves initialy increase then decrease due to the law of diminishing marginal returns.

• Marginal productions : It is the change in total production divided by the change in quantity of resources or inputs.
• Average production : It is the total production divided by the quantity of economic resources.

Question 4.
Clarify the concept of opportunity cost.
Answer:
Opportunity cost in the value of the next best alternative in choosing an alternative.
For example suppose to produce one unit of goods x, the producer has to sacrifice production of 2 units of x, the 2x is the opportunity cost producing one unit of x.

Question 5.
Why short run average cost curve is of “U” shaped ? Write briefly.
Answer:
Long run average cost curve is also known as ‘Envelope curve’. Where as LAC is a continuous curve. .The reason behind the ‘U’. Shape the curve is the Law of Returns to scale. According to this law, as plant size increases, the average cost of production decrease due to economies of scale.”

Question 6.
What do you mean by Total Revenue, Average Revenue and Marginal Revenue ?
Answer:

• Total Revenue : The income earned by a seller or producer after selling the output is called the total revenue.
• Average Revenue : Average Revenue refers to the revenue obtained by the seller by selling the per unit commodity. It is obtained by divideding the total revenue by total output.

Marginal Revenue : Marginal revenue is the change in total revenue which results from the sale of one more or one less unit of output.

Question 7.
Write the three characteristics of perfect competitive market.
Answer:
Characteristics of the Market : Main characteristics (or features) of the market are as follows:

1. One Area : The term market in Economics does not refers to any fixed place but indicates that area where buyers and sellers are present and compete with each other.
2. Presence of both Buyers and Sellers : An area is called the market where both buyers and sellers are present. Absence of any one creates hindrance in converting the area into market.
3. One Commodity : In Economics, every commodity has different market, e.g., market of wheat, market of sugar etc.
4. One Price of the Commodity : Market contains one single price of the commodity due to competition between buyers and sellers.

Hence, on the basis of above feature the market can be defined as :
“In economics market signifies the presence of such groups of buyers and sellers of a commodity who freely competer with each other and as a result one price prevails in the market.”

Question 8.
What is the difference between monopoly and monopolistic competition ?
Answer:
Monopoly differs from perfect competition in the following ways :

1. In monopoly, there is a single seller (or firms) of a product whereas under perfect competition there are large number of sellers (or firms).
2. A monopolist produces or sells a product which has no close substitute on the other hand, under perfect competition, the products sold by the various firms are homogeneous or identical. They are perfect substitutes of each other.
3. In case of monopoly, there is no freedom of entry in the industry whereas under perfect competition, there is free entry and exit of firms in the industry.
4. For a monopolist firm, the demand curve of its product slopes downward to the right. On the other hand, a perfect competitive firm faces a perfectly elastic downward curve (i.e., a horizontal straight line).

Question 9.
What is meant by equilibrium price and equilibrium quanity ?
Answer:
“When the supply and demand curves intersect, the market is in equilibrium. This is where the quantity demanded and quality supplied are equal. The corresponding price is the equilibrium price or market clearing price, the quantity is the equilibrium quantity.”

Question 10.
Differentiate between national income and domestic income.
Answer:
Difference between National Income and domestic Income :

• National Income : “It is the sum total of factor incomes earned or generated by normal residents of a country during on accounting year.”
• Domestic Income : “It is the sum total of factor incomes generated by all the production units located with in domestic territory of a country during an accounting year.”.

Difference : The difference between the two is net factor income from abroad which is added to domestic income to get national income.

symbolical : National income = Domestic income + Net factor income from abroad.

Question 11.
What is meant by private income ? What is the difference between private income and personal income ?
Answer:
Private income refers to.that income which accrues to private sector from all sources, both within domestic territory as well as from rest of the world.
Difference between private income and personal income :
Private Income :

1. It includes income of only private sector.
2. It includes both factor income and transfer earnings.
3. Interest on national debt is a part of national income.

Personal Income :

1. It is a receipt concept. It does not include the income of public sector.
2. It includes transfer income of households and individuals.
3. It includes interest on national debts.

Question 12.
Factor income is divided into how many classes ?
Answer:
Factor income is devided into three classes :

1. Rent income
2. Wages income
3. Profit.

Question 13.
What are the precautions related to the calculation of income method ?
Answer:
Following are the precautions related to income method :

1. Income from the sale of second hand goods
2. Transfer payments
3. Sales of shares and bonds
4. Income from Illegal activities
5. Wind full gains
6. Imputed Rent
7. Indirect Takes
8. Corporation Tax and income tax.
9. Deata Duties, Gift tax
10. Travelling Allowances.

Question 14.
What is meant by under employment
equilibrium and over full employment equilibrium ?
Answer:
Underemployment equilibrium : refers to a situation with a persistent shortfall relative to full „ employment and potential output so that unemployment is higher than at the natural rate of unemployment.”

Over full employment equilibrium occurs when a country’s gross domestic product (GDP) is higher than normal.

Question 15.
Write the names of main measures of monetary policy.
Answer:
Following are the measures of monetary i policy of India :

1. Measures of Expansion of currency.
2. Measures of credit control
3. Quantitative credit control
4. Quantitative credit control
5. Statutory liquidity ratio
6. Cash reserve ratio
7. Multiple rate of interest
8. Repo Rate and Reverse repo rate.

Question 16.
Describe the various types of production cost.
Answer:
Following are the types of production cost.
Money cost :
(a) Explicit cost
(b) Implicit cost
(c) Normal profit.

Question 17.
What is an economic activity ?
Answer:
Economic activity is an important component , of subject matter of economics. All economic activities arising out of unlimited wants and scarce means are included in the subject matter of economics.

According to the modern economists, “that activity is called economic activity which is related to the use of limited resources for satisfying human wants.”

Question 18.
What do you understand by Micro economics ?
Answer:
Small units of an economy are included in micro 1 economics e.g. one consumer, one producer, one firm, one industry etc. In other words, individual units are studied in micro economics. According to K.E. Boulding, “Micro economics may be defind as that branch of analysis, which studies the economics behaviour of the individual unit, may be a person, a particular house-hold or a particular firm. It is a study of one particular unit rather than all the units combined together.”

Question 19.
Define capitalist economy.
Answer:
Capitalist economy is a system of economic organisation featured by the private ownership and the use of private profit of man-made and the nature-made capital or in other words, capitalist economy is that economy in which means of production are controlled and regulated by private organisation. Market economy contains the following important features

1. Private property
2. Economic freedom
3. Laissez faire & free trade
4. Competition
5. Price mechanism

Question 20.
Explain the Law of Diminishing Marginal Utility.
Answer:
Law of diminishing marginal utility is a fundamental and universal law. According to this law, as we go on utilizing standard additional units of commodity continuously, marginal utility obtained from use of every additional unit decreases. It occurs or happens in all goods and services. Therefore, this law is called fundamental and universal law of satisfaction.

According to this law, as the stock of goods increases with people, marginal utility obtained from additional units of that commodity decreases after a limit.

Question 21.
Explain the circular flow income.
Answer:
Production gives birth to income, income to consumption, consumption to expenditure and again expenditure to income and production. Thus, circular flow of income earning economic activities takes place in the economy.

According to hipsey, “The circular flow of income is the flow of payment and receipt between domestic firms and domestic households.”

Hence, the circular flow of income refers to flow of money income or the flow of goods and services across different sectors of the economy in a circular form.

Question 22.
Distinguish between national income and domestic income.
Answer:
National income :

1. It is related to the generation of income by public and private sector.
2. It goes not include transfer income.
3. It does not include interest on national debts.
4. It include corporate tax and corporate savings.

Domestic Income :

1. It is a receipt concept. It does not include the income of public sector.
2. It includes transfer income of households and individuals.
3. It includes interest on national debts.
4. It neither includes corporate tax nor corporate savings.

Question 23.
Define commercial bank.
Answer:
Commercial banks perform general banking functions. A commercial bank is an institution which deal with money and credit. It accepts deposits from the public, makes the fund available to those who need them and helps in remittance of money from one place to another.

1. According to Banking Regulation Act, “Banking means the accepting for the purpose of tending and investment of deposits of money from the public, repayable on demand or otherwise, and with draw able by cheque, draft, order or otherwise.”
2. According to Horace white, “Bank is a manufacturer of credit and a machine for facilitating exchanges.”

Question 24.
Explain the subject matter of economics.
Answer:
Subject Matter of Economics : Various economists have presented the subject matter of economics in different ways. On the basis of various economists’ view points, the subject matter of economics can broadly be divided into four categories :

1. Wealth-related Viewpoint: Classical economists Adam Smith, J.B. Say, Walker, Senior etc. have included wealth, its earning, distribution and use in the subject matter of economics. These economists have included economic man and his activities into the subject matter of economics.
2. Welfare-related Viewpoint: Marshall, Pious, Canon established the concept of human-welfare (instead of wealth) in the subject matter of economics. According to welfare-related viewpoint, those economic activities should be included in the subject matter of economics which are associated with physical welfare.
3. Scarcity-related Viewpoint: Robbins has included ‘problem of choice’ related to limited resources and unlimited ends in the subject matter of economics. According to Robbins those human activities are included in subject matter of economics with which human being tries to fulfill his unlimited ends with limited resources.
4. Growth-related Viewpoint : Modern economists like Samuelson has included growth-based activities in the subject matter of economics. According to Samuelson both the aspects i.e. distribution of limited resources’ and ‘economic growth’ are the part of subject matter of economics.

Question 25.
Explain marginal utility.
Answer:
Marginal Utility is the addition to the total utility by consuming an extra unit of a commodity by the consumer. Symbolically:
MU = ATU/An or, MU = TU – TU„
Law of diminishing marginal utility states that consumer consumes more and more of commodity, the marginal utility obtained from an additional unit of it goes on diminishing, other things remaining the same.

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 law of demand with the help of a diagram. Explain any five factors affecting the demand of a commodity.
Answer:
Law of demand states that there is an inverse relation between the price of a commodity and its quantity demanded assuming all other factors effecting demand remain constants. It means that when the price of a goods falls, the demand for the goods rises and when price the demand falls.

There is same price in the market. All consumers purchase commodity according to their needs. The marker demand curve is the total amount demanded by all consumers at different prices. The market demand curve slopes from left down to the right.
Factors affecting the demand of commodity are as below :

1. Price of the commodity itself: When a commodity is selling at very high price, only rich people are able to buy it. So the demand of commodity will be less. But when the price is low more and more people will be able to buy it and the demand of the commodity would be more. Thus, the demand of the commodity is greatly influenced by its price.
2. Price of other related goods : The demand for a commodity is also influenced by prices of other related goods as substitutes.
3. Leves of income of the consumer : consumers demand is also influenced by the size of this income.This is but natural that with increase in the level of income, there is increase in the demand of goods and services.
   (iv) Tastes and preference of consumers : Tastes and preference of the consumers also influence his demand. A taste, fashions, preferences of the consumer keep on changing and is his demand.
4. Population : The change in the population in a country changes the demand.
5. Income distribution: It is only the size or level of income which affects the demand but also the nature of income distributions in the country
6. State of Trade : During a period of boom a period in which there is higher circulation of money and the production level is at a peak, the employment of resources reaches the optimum level. Consequently there is more purchasing power in the hands of the people.

Question 27.
What is meant by returns to scale ? Using a suitable diagram, explain the concepts of increasing constant and diminishing returns to scale.
Answer:
Return to scale : Return to scale refers to long run production when none of the factors of production remains fixed. All factors of production became variable and they can be changed also.
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.”
Return of scale is of three types as discussed below :
(i) Increasing Returns to scale : Increasing returns to scale occur when a given percentage increase in all factor inputs causes proportionately greater increase in output. In this way, it factors of production are increased 10%, then production increased more than 10%. Increasing return to scale occur due to division of labour and specilization.

(ii) Constant Returns to scale : Constant return to scale occurs when a given percentage increase in all factors inputs causes equal proportionate increase in output. If factors of production are increased 10% then production also increased by 10% and vice versa.

(iii) Diminishing Return to scale : Diminishing returns to scale occurs when a given percentage increase in factors of productions causes proportionately lesser increase in output.
In diminishing Retur to scale =
Proportionate increase inproduction <
Proportionate increase in factors of production.

Question 28.
What do you mean by double counting problem ? How can it be avoided Explain with an illustration. .
Answer:
Meaning : Double counting means counting of the value of the same product (or expenditure) more than once. How ? According to output method, of calculating national income value of only final goods and services produced by all the production units of a country during a year should be counted. In other words, value of intermediate goods which enter into final goods Ce.g. paper used in printing of books, raw cotton used in garments, wheat used in making breads, should not be taken into account.

But in actual practice, while taking value of final goods, value of intermediate goods also gets included because every producer treats the commodity he sells as final product irrespective of weather it is used as intermediate or final good. For instance, while taking value of final goods like cycles the value of tyres, tubes, frames, bells etc. (intermediate goods) used in manufacturing these cycles also gets included inadvertently.

In this way certain items are counted more than once resulting in over-estimation of national product to the extent of the value of intermediate goods included. This is called the problem of double counting which means counting value of the same commodity more than once.

How to avoid Double Counting : Theoritically we may say that there may be two alternative ways of avoiding double counting namely

1. final product approach
2. value added approach.

But in actual practice, double counting still occurs unintentionally in final product approach because every producer treats the product he sells as final product though the same night have been used by the buyer as an intermediate product.

Therefore, this problem is perfectly solved by value added method according to this method ‘instead of taking value of final products, value added by each firm at each stage of production is included.

Clearly value added by all the four firms is Rs. 3500 comprising Rs. 1000 by A+ Rs 500 by B + Rs. 700 by C + Rs. 1300 by D. There is no scope of double counting in this method. Thus to avoid double counting, the value added method also known as industry of origin method is used in computation of national income. It is worth mentioning that total value added is equal to value of final product.

Question 29.
Define investment multiplier. What is the relationship between investment and marginal propensity to consume.”
Answer:
Difinition of Investment multiplier :
According to Dillard, “Investment multiplier is the ratio of an increase of income to given increase in investment.” Relation between Multiplier and marginal propensity to consume (MPC) : Keynesian investment multiplier depends on marginal propensity to consume (MPC). Higher the marginal propensity to consume, greater will-be the size of multiplier, on the contrary lower the MPC, smaller will be the size of multiplier.
So, there is direct relation between multiplier and MPC
multiplier (k) = \(\frac { 1 }{ 1-MPC }\)
We know that k = \(\frac { ΔY }{ Δ1 }\)
Y=C +I; ΔY = ΔC +ΔI
ΔI = ΔY -ΔC
Here ΔI = change in Investment ΔY = change in Income and ΔC = change in consumptions.
putting the value of AI in equation (i) we have
k = \(\frac { ∆Y }{ ∆I }\)
Dividing right hand side of the equation by ΔY

It is clear that by knowing the value of either MPC or MPS, the value of multiplier can be calculated. Higher the MPC ‘greater will be the value of multiplier. Thus, MPC and multiplier are directly related while MPS and Multiplier are inversely related.

Question 30.
What is excess demand How can it be controlled.
Answer:
(i) Excess Demand : Meaning : If aggregate demand and aggregate supply attain equilibrium at the point beyond full employment, the situation of excess demand appears. In other words, when aggregate demand exceeds aggregate supply at full employment level, excess demand arises.

Thus, “Excess demand refers to a situation in which aggregate demand becomes excess of aggregate supply corresponding to full employment in the economy.” Excess Demand Aggregate Supply corresponding to Full Employment Level

(ii) In situation of excess demand, the aggregate demand exceeds the required demand, hence, increased demand will not put any reaction on employment and production levels because factors are already at full employment level. In this situation of excess demand (in which aggregate demand exceeds aggregate supply) the prices of goods and services rise and situation of inflation arises in the economy.
Characteristics of Excess Demand :

1. When existing aggregate demand exceeds aggregate supply of full employment level, it becomes the situation of excess demand.
2. When aggregate demand exceeds required demand, there is not effect on employment and production level and they remain constant.
3. The difference between aggregate demand and aggregation supply is tremed as ‘Inflationary Gap’ Thus, inflationary gap is measured as the difference, between ‘aggregate demand beyond full employment’ and aggregation demand at full employment’.
   i. e., Inflationary Gap = Aggregate Demand beyond Full Employment – Aggregate Demand at Full Employment.
4. Higher the inflationary gap, more will be the excess demand, i.e., inflationary gap is the measurement of excess demand. Excess Demand : Diagrammatic Representation

(iii) In adjoining fig the situation of excess demand has been shown. Aggregate demand curve AD refers to the situation of full employment. At full employment level Y, required aggregate demand is EY. Aggregate demand beyond full employment is shown by AD] line where aggregate demand becomes FY. Existing aggregate demand FY exceeds required aggregate demand EY and the difference EF becomes excess demand.
Diagrammatically,

Excess Demand = FY – EY – EF
Effects on Excess Demand

(a) Effects on Production : In situation of excess demand, production remains constant, excess demand only puts excess pressure on existing supply.

(b) Effects on Employment: In situation of excess demand, employment remains unaffected because the economy is already at full employment level and hence, there is no possibility of employment increase due to increased demand.

(c) Effects on Prices : The economy being already working at full employment level, no possibility of production increase appears in case of excess demand. Hence, supply falls short of excess demand and as a result, prices of goods and services start rising. In adjoining fig., OL is the production level at full employment level which remains constant even if aggregate demand increases to AD (7 from ∆DF. In this situation of excess demand, only price level rises from OP₁ to OP₂?

Question 31.
Explain the law of demand and what are its assumptions ?
Answer:
Law of demand-Low of demand explains quantitative relation beholden price of goods and quantity demanded. Every consumer has a psychology to buy less amount or quantity of anything of high price and more quantity of low price, ceteris Paribus (other things being equal), there is inverse relationship between price of a goods and when price is low, demand is high.
Thus, p ∞ \(\frac { 1 }{ Q }\) – where,
P = Price of commodity
Q =Quantity demanded

Assumptions of the law of demand-Law of demand is based on few assumptions. These assumptions are-

1. Consumer’s income should remain contant.
2. Consumer’s taste, nature, etc. should remain constant.
3. Consumer remains unknown with new substitutes.
4. There is no possibility of price change in future.

Question 32.
What do you understand by National Income ? Explain any two methods of calculating National Income.
Answer:
Net National product at factor cost (NNPFC) is known as ‘National Income’ NNPFC is the sum total of net domestic product at factor cost and net factor income from abroad.

Net National product at factor cost (NNPFC) or national income is the sum total of factor incomes (rent + interest + profit + wages) generated within the domestic territary of a country, alongwith net factor income from abroad during a year.
NNPFC is the sum total of factor incomes earned by normal residents of a country during year.

(a) 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-

• Primary sector
• Secondary sector
• Tertiary sector

(b) Second step-Calculation of net value of output to estimate the net value added in each identified enterprise in first step the following estimated 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 enterprises with their market price. Value of intermediate consumption is calculated by using the prices paid by the enterprise. Consumption of fixed capital is also estimated as per rules and regulations.
[Net value added = Value of output – Intermediate consumption – Net indirect taxes]

(c) Third step-Calculation of net factor income from abroad.
The third and final step in the estimation of national incomes 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.

Question 33.
What is Barter system ? Mention its difficulties.
Answer:
The direct exchange of goods for goods without the use of money is called barter system. The major drawbacks of the barter system are-

1. Lack of double coincidence of wants-The lack of double coincidence of wants is the major drawback of the barter system. It is very rare when the owner of some goods or services could find someone who wanted his goods or services and possessed that goods or services that the first person wanted. No, exchange is possible if the double coincidence of wants is not there.
2. Lack of common measure of value-The second main drawback of barter system is the absence of a common unit of measurement in which the value of goods and services can be measured. In the absence of common unit, proper accounting is not possible.
3. Lack of standard for deferred payments- The third drawback of the barter system is that it lacks any satisfactory unit to engage in contracts involving future payments. In a barter economy, future payments would have to be stated in specific goods or services which may involve disagreement over the quality of goods even on the commodity used for repayment.
4. Lack of store of value-The bater system does not provide for any method of storing purchasing power for future use. It can be stored only in terms of commodities which subject to storage cost, durability, increases or decreases in the value of goods and the difficulty in disposing of the commodity without loss

Bihar Board 12th Maths Objective Questions and Answers

Bihar Board 12th Maths Objective Answers Chapter 2 Inverse Trigonometric Functions

Question 1.

Answer:
(d) \(-\frac{\pi}{6}\)

Question 2.

Answer:
(b) \(\frac{\pi}{3}\)

Question 3.

Answer:
(b) \(\frac{\pi}{3}\)

Question 4.

Answer:
(a) \(\frac{\pi}{4}\)

Question 5.

Answer:
(b) \(\frac{3 \pi}{4}\)

Question 6.

Answer:
(d) \(\frac{2 \pi}{3}\)

Question 7.

Answer:
(a) \(\tan ^{2}\left(\frac{\alpha}{2}\right)\)

Question 8.

Answer:
(b) \(\frac{6}{17}\)

Question 9.
If tan^-1 (x – 1) + tan^-1 x + tan^-1 (x + 1) = tan^-1 3x, then the values of x are
(a) \(\pm \frac{1}{2}\)
(b) 0, \(\frac{1}{2}\)
(c) 0, \(-\frac{1}{2}\)
(d) 0, \(\pm \frac{1}{2}\)
Answer:
(d) 0, \(\pm \frac{1}{2}\)

Question 10.
If 6sin^-1 (x² – 6x + 8.5) = π, then x is equal to
(a) 1
(b) 2
(c) 3
(d) 8
Answer:
(b) 2

Question 11.
3 tan^-1 a is equal to

Answer:
(d) \(\tan ^{-1}\left(\frac{3 a-a^{3}}{1-3 a^{2}}\right)\)

Question 12.

Answer:
(d) \(\frac{1}{5}\)

Question 13.
The equation 2cos^-1 x + sin^-1 x = \(\frac{11 \pi}{6}\) has
(a) no solution
(b) only one solution
(c) two solutions
(d) three solutions
Answer:
(a) no solution

Question 14.

Answer:
(d) x

Question 15.
If tan^-1 2x + tan^-1 3x = \(\frac{\pi}{4}\), then x is
(a) \(\frac{1}{6}\)
(b) 1
(c) (\(\frac{1}{6}\), -1)
(d) none of these
Answer:
(a) \(\frac{1}{6}\)

Question 16.

Answer:
(c) \(\sqrt{\frac{x^{2}+1}{x^{2}+2}}\)

Question 17.

Answer:
(a) \(\sqrt{a b}\)

Question 18.
If tan^-1 x – tan^-1 y = tan^-1 A, then A is equal to
(a) x – y
(b) x + y
(c) \(\frac{x-y}{1+x y}\)
(d) \(\frac{x+y}{1-x y}\)
Answer:
(c) \(\frac{x-y}{1+x y}\)

Question 19.

Answer:
(c) \(\pm \sqrt{\frac{5}{2}}\)

Question 20.
The value of cot^-1 9 + cosec^-1(\(\frac{\sqrt{41}}{4}\)) is given by
(a) 0
(b) \(\frac{\pi}{4}\)
(c) tan^-1 2
(d) \(\frac{\pi}{2}\)
Answer:
(b) \(\frac{\pi}{4}\)

Question 21.

Answer:
(a) \(\frac{6}{17}\)

Question 22.

Answer:
(d) none of these

Question 23.

Answer:
(b) 0

Question 24.

Answer:
(d) \(\frac{1}{\sqrt{2}} \leq x \leq 1\)

Question 25.
cos^-1[cos(2cot^-1(√2 – 1))] = ______
(a) √2 – 1
(b) 1 + √2
(c) \(\frac{\pi}{4}\)
(d) \(\frac{3 \pi}{4}\)
Answer:
(d) \(\frac{3 \pi}{4}\)

Question 26.
The range of sin^-1 x + cos^-1 x + tan^-1 x is
(a) [0, π]
(b) \(\left[\frac{\pi}{4}, \frac{3 \pi}{4}\right]\)
(c) (0, π)
(d) \(\left[0, \frac{\pi}{2}\right]\)
Answer:
(b) \(\left[\frac{\pi}{4}, \frac{3 \pi}{4}\right]\)

Question 27.

Answer:
(c) \(\frac{\pi}{4}\)

Question 28.
Find the value of sec² (tan^-1 2) + cosec² (cot^-1 3)
(a) 12
(b) 5
(c) 15
(d) 9
Answer:
(c) 15

Question 29.

Answer:
(d) \(\frac{2}{x}\)

Question 30.
The equation sin^-1 x – cos^-1 x = cos^-1(\(\frac{\sqrt{3}}{2}\)) has
(a) unique solution
(b) no solution
(c) infinitely many solution
(d) none of these
Answer:
(a) unique solution

Question 31.
Solve for x : {xcos(cot^-1 x) + sin(cot^-1 x)}² = \(\frac{51}{50}\)
(a) \(\frac{1}{\sqrt{2}}\)
(b) \(\frac{1}{5 \sqrt{2}}\)
(c) 2√2
(d) 5√2
Answer:
(b) \(\frac{1}{5 \sqrt{2}}\)

Question 32.

Answer:
(c) tan^-1(15)

Question 33.

Answer:
(b) \(\sqrt{\frac{3}{76}}\)

Question 34.

Answer:
(d) \(\frac{\pi}{4}\)

Question 35.
If sin^-1(x² – 7x + 12) = nπ, ∀ n ∈ I, then x =
(a) -2
(b) 4
(c) -3
(d) 5
Answer:
(b) 4

Question 36.
If cos^-1 x + sin^-1 x = π, then the value of x is
(a) \(\frac{3}{2}\)
(b) \(\frac{1}{\sqrt{2}}\)
(c) \(\frac{\sqrt{3}}{2}\)
(d) \(\frac{2}{\sqrt{3}}\)
Answer:
(c) \(\frac{\sqrt{3}}{2}\)

Question 37.
If sin^-1 x – cos^-1 x = \(\frac{\pi}{6}\), then x =
(a) \(\frac{1}{2}\)
(b) \(\frac{\sqrt{3}}{2}\)
(c) \(-\frac{1}{2}\)
(d) \(-\frac{\sqrt{3}}{2}\)
Answer:
(b) \(\frac{\sqrt{3}}{2}\)

Question 38.
If tan^-1 (cot θ) = 2θ, then θ is equal to
(a) \(\frac{\pi}{3}\)
(b) \(\frac{\pi}{4}\)
(c) \(\frac{\pi}{6}\)
(d) None of these
Answer:
(c) \(\frac{\pi}{6}\)

Question 39.
cot(\(\frac{\pi}{4}\) – 2cot^-1 3) =
(a) 7
(b) 6
(c) 5
(d) None of these
Answer:
(a) 7

Question 40.
If tan^-1 3 + tan^-1 x = tan^-1 8, then x =
(a) 5
(b) \(\frac{1}{5}\)
(c) \(\frac{5}{14}\)
(d) \(\frac{14}{5}\)
Answer:
(b) \(\frac{1}{5}\)

Question 41.

Answer:
(d) \(-\frac{24}{25}\)

Question 42.
sin^-1 (1 – x) – 2sin^-1 x = \(\frac{\pi}{2}\)
(a) 0
(b) 1/2
(c) 0, 1/2
(d) -1/2
Answer:
(a) 0

Question 43.
2tan^-1(cos x) = tan^-1(2cosec x)
(a) 0
(b) π/3
(c) π/4
(d) π/2
Answer:
(c) π/4

Question 44.

Answer:
(a) \(\sqrt{\frac{x^{2}+1}{x^{2}+2}}\)

Question 45.

Answer:
(a) \(\frac{3 \pi}{5}\)

Question 46.
The domain of the function defind by f(x) = \(\sin ^{-1} \sqrt{x-1}\) is
(a) [1, 2]
(b) [-1, 1]
(c) [0, 1]
(d) none of these
Answer:
(a) [1, 2]

Question 47.
The value of sin (2tan^-1 (0.75)) is equal to
(a) 0.75
(b) 1.5
(c) 0.96
(d) sin 1.5
Answer:
(c) 0.96

Question 48.
The value of expression 2 sec^-1 2 + sin^-1(\(\frac{1}{2}\))
(a) \(\frac{\pi}{6}\)
(b) \(\frac{5 \pi}{6}\)
(c) \(\frac{7 \pi}{6}\)
(d) 1
Answer:
(b) \(\frac{5 \pi}{6}\)

Question 49.

Answer:
(c) \(\frac{24}{25}\)

Question 50.
The value of the expression \(\tan \left(\frac{1}{2} \cos ^{-1} \frac{2}{\sqrt{3}}\right)\)
(a) 2 + √5
(b) √5 – 2
(c) \(\frac{\sqrt{5}+2}{2}\)
(d) 5 + √2
Answer:
(b) √5 – 2

Question 51.

Answer:
(a) 4tan^-1 x

Question 52.
The number of real solutions of the equation is

(a) 0
(b) 1
(c) 2
(d) none of these
Answer:
(c) 2

Bihar Board 12th Chemistry Model Papers

Bihar Board 12th Chemistry Model Question Paper 3 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.
Solid X is a very hard solid which is electrical insulator in solid as well as in molten state and has extremely high melting point. What type of solid is it ?
(a) Ionic solid
(b) Covalent solid
(c) Metallic solid
(d) Molecular solid
Answer:
(b) Covalent solid

Question 2.
Examples of few solids are given below. Find out the example which is not correctly matched.
(a) Ionic solids – NaCl, ZnS
(b) Covalent solids – H₂,I₂
(c) Molecular solids – H₂O_(s)
(d) Metallic solids – Cu, Sn
Answer:
(b) Covalent solids – H₂,I₂

Question 3.
Which of the following solids is the structure of CsCI crystal ?
(a) Body centred cubic
(b) Simple cubic
(c) Face centred cubic
(d) Edge centred cubic
Answer:
(a) Body centred cubic

Question 4.
Which of the following does not represent a type of crystal system ?
(a) Triclihic
(b) Monoclinic
(c) Rhombohedral
(d) Isotropical
Answer:
(d) Isotropical

Question 5.
Which of the following primitive cells show the given parameters ?
a ≠ b ≠ c, α = β = γ = 90°
(a) Cubic
(b) Tetragonal
(c) Orthorhombic
(d) Hexagonal
Answer:
(c) Orthorhombic

Question 6.
In amalgam of mercury with sodium, solvent is
(a) mercury
(b) sodium
(c) amalgam
(d) none of these
Answer:
(b) sodium

Question 7.
What is the mole fraction of glucose in 10% w/W glucose . solution ?
(a) 01
(b) 0.02
(c) 03
(d) 0.04
Answer:
(a) 01

Question 8.
The cell reaction of the galvanic cell:

(a) Hg + Cu²⁺→ Hg²⁺ + Cu
(b) Hg + Cu²⁺→ Cu⁺ + Hg⁺
(c) Cu + Hg → CuHg
(d) Cu + Hg²⁺ → Cu²⁺ + Hg
Answer:
(d) Cu + Hg²⁺ → Cu²⁺ + Hg

Question 9.
Which of the following reaction is possible at anode ?
(a) 2Cr³⁺ +7H₂O → Cr₂O₂^2-+14H⁺
(b) F₂ → 2F^–
(c) (1/2)O₂ +2H⁺→H₂O
(d) None of these.
Answer:
(a) 2Cr³⁺ +7H₂O → Cr₂O₂^2-+14H⁺

Question 10.
Consider the reaction :

\(-\frac{\mathrm{d}\left[\mathrm{N}_{2} \mathrm{O}_{4}\right]}{\mathrm{dt}}=\mathrm{k} \text { and } \frac{\mathrm{d}\left[\mathrm{NO}_{2}\right]}{\mathrm{dt}}=k^{\prime} \)
(a) 2 k’ = k
(b)k’ = 2k
(c)k’=k
(d) K = 1/4 k’
Answer:
(b)k’ = 2k

Question 11.
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 = k₃
(b) k₁=3k₂-2k₂
(c) 1.5= 3k₂ = k₃
(d) 2k_x =k₂= 3k₃
Answer:
(c) 1.5= 3k₂ = k₃

Question 12.
The term activation of adsorbent is used when
(a) adsorbing power is increased by increasing surface area by making the surface rough
(b) adsorbing power is increased by dipping the surface in acid to make it smooth
(c) adsorbing power is increased by dissolving it in water
(d) adsorbing power is decreased to reduce the extent of adsorption
Answer:
(a) adsorbing power is increased by increasing surface area by making the surface rough

Question 13.
Which of the following is less than zero during adsorption ?
(a) ΔG
(b) ΔS
(c) ΔH
(d) All of these
Answer:
(d) All of these

Question 14.
In which of the following the name of the ore is not matched with its formula ?
(a) Cassiterite – SnO₂
(b) Limonite – Fe₂O₃.3H₂O
(c) Siderite – FeCO₃
(d) Anglesite – PbCO₃
Answer:
(d) Anglesite – PbCO₃

Question 15.
Pyrolusite is ………………
(a) a sulphide ore of Mn
(b) an oxide ore of Mn
(c) a carbide ore of P
(d) a chloride ore of Zn
Answer:
(b) an oxide ore of Mn

Question 16.
Nitrogen forms stable N₂ molecule but phosphorus is converted to.P₄ from P₂ because
(a) pπ – pπ bonding is strong in phosphorus
(b) pπ – pπ bonding is weak in phosphorus
(c) triple bond is present in phosphorus
(d) single P – P bond is weaker than N – N bond
Answer:
(b) pπ – pπ bonding is weak in phosphorus

Question 17.
The decreasing order of boiling points of the following hydrides is
(a) H₂O > SbH₃ > AsH₃ > PH₃ > NH₃
(b) H₂O > NH₃ > SbH₃ > AsH₃ > PH₃
(c) H₂O>SbH₃>NH₃>AsH₃>PH₃
(d) H₂O > PH₃ > AsH₃ > SbH₃ > NH₃
Answer:
(c) H₂O>SbH₃>NH₃>AsH₃>PH₃

Question 18.
Which of the following pairs of ions have the same electronic configuration ?
(a) Cu²⁺,Cr²⁺
(b) Fe³⁺,Mn²⁺
(c) CO³⁺+Ni³⁺
(d) SC³⁺ + cr ³⁺
Answer:
(b) Fe³⁺,Mn²⁺

Question 19.
The melting points of Cu, Ag and Au follow the order
(a) Cu > Ag > Au
(b) Cu > Au > Ag
(c) Au > Ag > Cu
(d) Ag > Au > Cu
Answer:
(b) Cu > Au > Ag

Question 20.
When one mole of each of the following complexes is treated with excess of AgN0₃, which will give maximum amount of AgCl ?
(a) [Co(NH₃)₆]Cl₃
(b) [Co(NH₃)₅Cl]Cl₂
(c) [Co(NH₃)₄Cl₂]Cl
(d) [Co(NH₃)₃Cl₃]
Answer:
(a) [Co(NH₃)₆]Cl₃

Question 21.
According to Werner’s theory of coordination compounds.
(a) primary valency is ionisable
(b) secondary valency is ionisable
(c) primary and secondary valencies are ionisable
(d) neither primary nor secondary valency is ionisable
Answer:
(a) primary valency is ionisable

Question 22.
Haloalkanes contain halogen atom(s) attached to the sp³ hybridised carbon atom of an alkyl group. Identify haloalkane from the following compounds.
(i) 2-Bromopentane
(ii) Vinyl chloride
(iii) 2-Chloroacetophenone
(iv) Trichloromethane
(a) Only (ii)
(b) (ii) and (iv) only
(c) (i) and (iv) only
(d) (i), (ii) and (iii) only
Answer:
(c) (i) and (iv) only

Question 23.
The IUPAC name of tertiary butyl chloride is ……………..
(a) 2-chloro-2-methypropane
(b) 3-chlorobutane
(c) 4-chlorobutane
(d) 1, 2-chloro-3-methylporpane .
Answer:
(a) 2-chloro-2-methypropane

Question 24.
A compound …………. has two tertiary alcoholic groups. The IUPAC name of this compound is
(a) 2, 3-dimethyl-1, 2-butanediol
(b) 3, 3-dimethyl-1, 2-butanediol
(c) 2, 3-dimethyl-2, 3-butanediol
(d) 2-methyI-2, 3-pentanediol
Answer:
(c) 2, 3-dimethyl-2, 3-butanediol

Question 25.
Which of the following is phenol ?
(a) Cresol
(b) Catechol
(c) Benzenol
(d) All of these
Answer:
(d) All of these

Question 26.
Ketones

can be obtained in one step by (where R and R’ are alkyl groups)
(a) hydrolysis of esters
(b) oxidation of primary alcohols
(c) oxidation of secondary alcohols
(d) reaction of alkyl halides with alcohols
Answer:
(c) oxidation of secondary alcohols

Question 27.
Ozonojysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of
(a) two ethylenic double bonds
(b) a vinyl group
(c) an isopropyl group
(d) an acetylenic triple bond
Answer:
(b) a vinyl group

Question 28.
Which of the following is not a primary amine ?
(a) tert-Butylamine
(b) sec-Butylamine
(c) Isobutylamine
(d) Dimethylamine
Answer:
(d) Dimethylamine

Question 29.
Which one of the following is aromatic amine ?

(d) Both (a) and (b)
Answer:
(d) Both (a) and (b)

Question 30.
Cellulose is a
(a) hexapolysaccharide
(b) pentapolysaccharide
(c) tripolysaccharide
(d) none of these
Answer:
(d) none of these

Question 31.
Which of the following is a non-reducing sugar ?
(a) Glucose
(b) Sucrose
(c) Maltose
(d) Lactose
Answer:
(b) Sucrose

Question 32.
Which of the following sets contain only addition homopolymers ?
(a) Polythene natual rubber, cellulose
(b) Nylon polyester, melamine resin
(c) Teflon, bakelite, orlon
(d) Neoprene, PVC, polythene
Answer:
(d) Neoprene, PVC, polythene

Question 33.
Teflon and neoprene are the examples of
(a) copolymers
(b) monomers
(c) homopolymers
(d) condensation polymers
Answer:
(c) homopolymers

Question 34.
Some drugs do not bind to the enzyme’s active site, instead bind to a different site of enzyme. This site is called
(a) allosteric site
(b) substrate site
(c) ionic site
(d) competitive site.
Answer:
(a) allosteric site

Question 35.
Drugs that bind to the receptor site and inhibit its natural function are called
(a) agonistic drugs
(b) antagonistic drugs
(c) antimicrobial drugs
(d) allosteric drugs.
Answer:
(b) antagonistic drugs

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.
What happens when
(a) ethanol is oxidised with acidified KMnO₄ solution ?
(b) ethanol is treated with PCl₅ ?
Answer:
(a) Ethanoic acid will be formed

(b) Chloroethane will be formed
C₂H₅OH + PCl₅ → C₂H₅Cl + POCl₃ + HCl

Question 2.
How will you convert
(a) aniline to 2, 4, 6 tribromoaniline ?
(b) acetamide to ethylamine ?
Answer:

Question 3.
(a) What is inert pair effect ?
(b) Why does BCI₃ act as Lewis acid ?
Answer:
Inert pair effect – The pairs of two electrons doesn’t participated in a chemical reaction of heavy outside & subnucleic non metal. This effect is called inert pair effect. BCl₃ behaves as Lewis acid due to the electron deficient in BCl₃

Question 4.
Explain the following :
(a) H₂S is a gas while H₂G is a liquid at room temperature.
(b) Carbon and silicon are tetravalent but Ge, Sn and Pb show divalency also.
Answer:
(a) Since H – 0 bond is more polar than H – S because of greater electronegativity difference in the bond participating atoms. Due to this, H₂O molecules are involved in the bending associates to be liquid at room temperature.

Where as, the intermolecular hydrogen bonding is negligible in the molecules of H₂S and does not associates, and it maintains the gaseous state at room temperature.

(b) Due to small shape of atoms of carbon and silicon and due to the maximum value of electron negativity. The carbon and silicon are tetravalent but the Sn, Pb shows divalency.

Question 5.
Write the IUPAC names of the following coordinate compounds :
(a) [Pt (NH₃)₂ Cl₂] Cl₂
(b) [Cr (NH₃)₄ Cl₂]⁺
Answer:
(a) [Pt (NH₃)₂Cl₂[Cl₂ → Diammine dicholorplatinum (iv) chloride.
(b) [Cr {NH₃)₄Cl₂]⁺ → Tetra aminedichloro chromium (iii) ion.

Question 6.
(a) Why are Cd²⁺ salts white ?
(b) Why does H₃PO₃ act as reducing agent but H₃PO₄ does not ?
Answer:
(a) Due to absence of unpaired electron CD²⁺ molecule is found CD²⁺ salt in white.
(b) The oxidation no. of P in H₃PO₃ in +3 so its oxidation no. can be increased, or we can say that H₃PO₃ acts as reducing agent while the oxidation no. of P is +5 in H₃ PO₄ . Therefore, we can say that H₃PO₃ acts as reducing agent but H₃PO₄ does not act as reducing agent.

Question 7.
Write IUPAC names of the following :
(a) [Cu (NH₃)₄]Cl₂
(b) K₄ [Fe (CN)₆ ]
Answer:
(a) Hexa-amino Copper (II) Chloride
(b) Potassium hexacyano Ferrate (II)

Question 8.
How will you convert the following ?
(a) Ethyl alcohol to Ethylene
(b) Acetylene to Benzene.
Answer:

Question 9.
How will you account for the following ? The electron affinity of fluorine is less than that of chlorine.
Answer:
The electron affinity of fluorine is less than that of chlorine because atom of chlorine is much smaller, hence electron density is very high, so an external electron can be added easily.

Question 10.
Give reasons for the following :
(a) Formic acid is stronger that Acetic acid.
(b) Aniline is less basic than methylamine.
Answer:
(a) Acidity of acid depends upon donation of proton
Since \(K a=\frac{\left[R C O O^{-}\right]\left[H_{3} O^{+}\right]}{[R C O O H]}\)
As we know, if the value of Ka is max, The Acidity will be maximum
HCOOH (Formic acid) ⇒ Ka= 1.77 x 10 ⁵
CH₃COOH⁺ (acidic acid) ⇒ Ka = 1.75 x 10⁵
Hence formic acid is more acidic than acetic acid.

(b) One pair of electron of nitrogen atom in aniline, which is overlaped with re-electron in ring. So, nitrogen atoms is positive charged or their is lack of electrons and it isn’t in the state than it can give paired electron to acid in comparison with methyl amine, due to this reason there is no overlapping so, aniline is a weak base than methyl amine.

Question 11.
Define the following : (a) Roasting (b) Smelting.
Answer:
Roasting – Roasting is the process by heating an ore in oxygen below its melting point to avoid volatile impurities.
Example –
CuS + 3O₂ → 2Cm₂ O+2SO₂ ↑
S + O₂  → SO₂ ↑
Smelting – Smelting is process in which metal oxide is obtained by heating with some reducing agent such metals are Zn, Fe, Sn, Cu.

Question 12.
Give two methods for the preparation of colloids.
Answer:
There are two methods of the preparation of colloids

• Condensation method
• Disperson method

Question 13.
State coiligative properties of dilute solution. Write down the different types of coiligative properties.
Answer:
The property, which depends upon number of atom or molecule of the solute and hot on their nature is called coiligative properties. There are four type of coiligative properties.

• Relative lowering of vapour pressure.
• Elevation in boiling point.
• Deperession in freezing point.
• Osmosis or Osmotic pressure.

Question 14.
The rate constant of a first order reaction is 60 sec^-1. How much time will it take to reduce 75% of its initial concentration ?
Answer:
Let initial concentration = amz ¹; According to Question 75% reduce
Let after t second, concentration remains \(\frac{a}{4}\)
As we know \(t=\frac{2.303}{t} \log \frac{a}{a-x}\)
\(t=\frac{2.303}{60} \log 4\)log 4 = 0.023 second
t = 0.023 seconds

Question 15.
Prove that the half-life of a first order reaction is independent of the initial concentration.
Answer:


From above, it is clear that the half-life of a first order reaction is independent of the initial concentration.

Question 16.
What do you mean by vapour pressure ? What happens to the vapour pressure. When (i) volatile solute is dissolved in solution, (ii) non-volatile solute is dissolved in solution ?
Answer:
Vapour pressure : It is defined as the pressure exerted by a vapour in thermodynamic equilibrium with its condensed phased (solid or liquid) at a given temperature in a closed sytem.

• Volatile solute increases vapour pressure of solvent.
• Nonvolatile solute lowers vapour pressure of solvent.

Question 17.
Differentiate between thermoplastic and thermosetting polymers. Give one example of each.
Answer:
Thermoplastic : Thermoplastic is a polymer that becomes pladable or moledable above a specific temperature and returns to a state upon cooling. Most thermoplastic have a high molecular weight.
Example : Polyethelene.

Thermosetting : A thermosetting is also known as thermoset is petrochemical material that irreversibly chures. The cure may be induced by heat through chemical reaction. A cured thermosetting resin is called a thermoset.
Example: Polyester.

Question 18.
How many moles of Cu will be deposited by passing 24125 coulombs of electric current from CuSQ₄ solution ?
Answer:
Cu⁺⁺ + 2e → Cu
2 x 96500 = 1 mole
Change 2 x 96500 columb Cu heated on = 1 mole 24125 columb change Cu on
1 Mole x \(\frac{24125}{2 \times 96500}\) = 0.125 mole

Long Answer Type Questions

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

Question 19.
(a) What is the difference between Ferromagnetism and paramagnetism ?
(b) For the cell shown below Zn (s) | ZnSO₄ (aq) || CuSO₄ (aq) | Cu (s) Calculate standard cell potential if standard state reduction electrode potentials for Cu²⁺ |Cu and Zn²⁺| Zn are + 0.34 V and – 0.76 V respectively.
Answer:
(a) Paramagnetism :

• The substances which are weakly attracted by magnetic field are called paramagnetic substances.
• These substances have permanent magnetic dipoles due to the presence of atom or ions with
  unpaired electrons.
• These substances lose their magnetism in the absence of magnetic field, e.g., TiO, CuO.

Ferromagnetism :

• The substances which are strongly attracted by magnetic field are called ferromagnetic substance.
• These substances show permanent magnetic even in the absence of magnetic field.
• e.g., Iron, Cobalt, Nickel & CrO₂
  Zn (s) \ZnSOI₄(a₂)\\CuSO₄(aq)\Cu (s)
  So, the cell reaction

At Anode : Oxidation

Question 20.
(a) What do you mean by the term elevation in boiling point’ ?
(b) State Raoult’s law. How is it applicable in determining the molecular weight of non-electrolyte solute ?
Answer:
(a) Elevation in boiling – The boiling point of a liquid may be defined as the temperature at which its vapour pressure becomes equal to atmospheric pressure. When we add a solute in any pure solvent, then the boiling point of the solution gets increased. This increasement is known as the elevation in boiling point.

(b) Raoult’s law – According to this law, the vapour pressure of a solution containing non-volatile solute is directly proportional to the mole fraction of the solvent.

Fig. Vapour pressure curve explaining elevation of boiling point. If a solution contains two components A (volatile solvent) and B (non-volatile solute) the vapour pressure of solution is given as
[Vapour Pressure of solution ] = [Vapour Pressure of solvent insolution (P_A)] α [ Mole fraction of solvent (X_a)]

P_A α X_A where, K is a proportionality constant
P_A = KX_a
Roult’s law is applicable in determing the molecular weight of non-electrolyte solute because unsaturated solute in solvent is pure solute than its boiling point is elevated. Hence, by this law we determine the molecular weight of non-electrolyte solute.

Question 21.
(a) Give the principle for the manufacture of nitric acid from ammonia.
(b) Give the reaction of 50% dilute HNO₃ with copper metal.
Answer:
(a) Due to following 11 parts of NH₃ and 89 part of mixture of air Pt gaize and heated at 100°, then we get (NO).
4NH₃+ 5O₂ → 4 NO + 6H₂O
2NO + O₂ → 2NO₂
2N0₂ + H₂O → HNO₃ + HNO₂
HNO₂ → HNO₃ +2NO+ H₂O
Thus, from above equations it is clear that NO. gives NO₂ due to its oxidation which mix in water and forms HNO₃ .

(b) 3Cw + dil. SHNO₃ → 3Cu(NO₃)₂ +4H₂O + 2NO

Question 22.
What happens when
(a) Ammonia reacts with excess of chlorine ?
(b) H₂S reacts with acidified K₂Cr₂O₇ solution ?
(c) Copper sulphate reacts with KI Solution ?
Answer:
(a) Ammonia reacts with excess of Chlorine
2NH₃ + 6Cl₂ → 2NCl₃ + 6HCl

(b) When H₂S reacts with acidified K₂Cr₂O₇ solution then a milky white or pale yellow colour of solution appears, due to the oxidations of H₂S to sulphur which are of colloidal nature.
H₂S + K₂Cr₂O₇ → K₂SO₄ + Cr₂O₃ + H₂O

(c) When copper sulphate (CuSO₄) reacts with KI solution, then a white precipitate of cuprous iodide is formed.
[CuSO₄ +2KI → Cul₂ + K₂SO₄] x 2
2CuI₂ → CuI₂ + I₂
2CuSO₄ + 4KI → 2K₂SO₄ + Cu₂I₂ + I₂

Question 23.
(a) Describe the following chemicals with suitable examples :
(i) Antipyretics
(ii) Antiseptics.
(b) Name the vitamin whose deficiency is responsible for night blindness.
(c) What are the starting materials used for preparing bakelite and PVC ?
Answer:
(a) (i) Antipyretics – Those chemicals which are used to lower down the body temperatures during high fever are known as antipyretics, e.g., Paracetamol, aspirin, etc.

Antiseptic – Those chemicals which are able to kill the micro-organisms, which are harmful to us are known as antiseptic. e.g., dettol or tincture of iodine can be applied an wounds, cuts, etc. They are also applied to reduce odours resulting from bacteria de-composition on the body.

(b) Vitamin A or A, is the vitamin whose deficiency is responsible for night blindness.

(c) Bakelite – Phenol and formaldehyde PVC – Methyl chloride

Question 24.
(a) Define the following with one example in each case : (i) Analgesics (ii) Antibiotics.
(b) How many molecules of ATP are produced per molecule of glucose in glycolysis ?
(c) What are synthetic rubbers ? Give one example.
Answer:
(a)

• Analgesics – Those chemicals, which are used for the relief of pain are known as analgesics.
  e.g., Moov, Fast relief are some malgesic creams which are helpful in pain.
• Antibiotics – Those chemicals which are obtained from micro-organisms (bacteria, Fungi and mos) that destroy O₂ inhibit the growth of other micro-organisms. e.g., Penicillin, streptomycin, tetracy lin, etc.

(b) 8 molecules of ATP are produced per molecule of glucose in glycolysis.
(c) Synthetic rubbers – Those rubbers which are manufactured artificially in laboratories are called synthetic rubbers. e.g., Neuprene.

Bihar Board 12th Physics Model Papers

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

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.
64 identical small drops combine to form a big drop. Calculate the capacity of big drop if capacity of each small drop is 5mF.
(a) 164 μF (b) 20 μF (c) 4 μF (d) 2n μF
Answer:
(b) 20 μF

Question 2.
The potential of A is 10 volt. The current flowing in the earth will be

(a) 10 ampere (b) 30 ampere (c) – 10 ampere (d) 0 ampere
Answer:
(a) 10 ampere

Question 3.
The force experienced by charged particle in mag netic field is
(a) F = qVB
(b) F = qVB sinθ
\((c) F=\frac{q}{\sqrt{B}}
(d) \quad F=\frac{V B \sin \theta}{q}\)
Answer:
(b) F = qVB sinθ

Question 4.
Which is not the unit of electric power?
(a) Watt (b) Ampere x Volt (c) Ampere²/ohm (d) Ampere ²/ohm
Answer:
(c) Ampere²/ohm

Question 5.
I Stat Coulomb is equal to Coulombs
(a) 3 x 10⁹
(b) 3 x 10^-9
(c)  \(\frac{1}{5} \times 10^{9}\)
(d) \(\frac{1}{3} \times 10^{-9}\)
Answer:
(d) \(\frac{1}{3} \times 10^{-9}\)

Question 6.
Two cell having emf E₁, internal resistance r is joined in parallel with resistance R. The power gives to resistance maximum if
(a) R = r/2
(b) R = r
(c) R = 2r
(d) R = 0
Answer:
(a) R = r/2

Question 7.
The resistance of ammeter is 0.05 W is joined with 1.5 V cell. If the current passes from circuit is 2A then internal resistance of cell is
(a) 1.0 Ω (b) 0.9 Ω (c) 0.8 Ω (d) 0.7 Ω
Answer:
(d) 0.7 Ω

Question 8.
Which substance is useful to make strong electro-magnet?
(a) air (b) soft iron (c) steal (d) alloy of copper & nickel
Answer:
(b) soft iron

Question 9.
Hysteresis shows
(a) paramagnetic substance (b) diamagnetic substance (c) ferromagnetic susbtance (d) None of these
Answer:
(b) diamagnetic substance

Question 10.
A°C. source is joined with L.C.R. circuit of angular frequency w. The peak value of current is

Answer:
(c)

Question 11.
The unit of impedance is
(a) mho (b) Ohm (c) Faraday (d) Ampere
Answer:
(b) Ohm

Question 12.
Self inductance of coil measures
(a) electrical inertia (b) electrical friction (c) induced emf (d) induced current
Answer:
(a) electrical inertia

Question 13.
A charged particle moves in uniform magnetic field. If the velocity of particle makes acute angle with magnetic field the path of particle is
(a) Rectilinear (b) Circular (c) Spiral (d) None of these
Answer:
(c) Spiral

Question 14.
The relation b/w electric field and magnetic field in the electromagnetic wave

Answer:
(a)

Question 15.
Maximum intensity in Young’s double slit experiment is Io. If one of will be the slit is closed then intensity

Answer:
(b)

Question 16.
Dynamo works on the principle
(a) on the Heating effect of current
(b) on electromagnetic induction
(c) on magnetic induction
(d) on electric induction
Answer:
(b) on electromagnetic induction

Question 17.
In a step up Transformer the number of coils in primary coils is N₁ and N₂ is secondary. Then
(a) N₁ = N₂ (b) N₁ < N₂ (c) N₁ > N₂ (d) None of these
Answer:
(b) N₁ < N₂

Question 18.
After increasing the angle of biprism, the fringe width
(a) Increases (b) Decreases (c) Remains constant (d) Indefinite
Answer:
(b) Decreases

Question 19.
If the wave length of light is A, and intensity of diffractive length is I then

Answer:
(c)

Question 20.
The phase difference between two waves for constructive interference is
(a) 0 (b) π (c) π/2 (d) 3π/4
Answer:
(b) π

Question 21.
Two convex lens are kept in contact. The equivalent lens is
(a) convex (b) concave (c) piano concave (d) 1 cylindrical
Answer:
(a) convex

Question 22.
The length of tube of simple microscope increases, then its magnifying power
(a) Increases (b) Decreases (c) Becomes zero (d) Remains constant
Answer:
(a) Increases

Question 23.
The energy of photon is
\((a) hv
(b) \frac{h v}{c}
(c) \mathrm{h} / \mathrm{v}
(d) \frac{v}{h}\)
Answer:
(b)

Question 24.
The sun obtaines radiant energy with
(a) Nuclear fission (b) Nuclear disintegration (c) Chemical reaction in nuclei (d) Nuclear fusion
Answer:
(d) Nuclear fusion

Question 25.
The energy of electron is proportive in z atomic number
(a) z (b) z² (c) z^-1 (d) z^-2
Answer:
(b) z²

Question 26.
The force between two proton inside the nucleus is
(a) only electrical (b) only nuclear (c) both (d) None of these
Answer:
(c) both

Question 27.
The process in which monochromatic, parallel and highly coherent light are obtained, is called
(a) LASER (b) MASER (c) RADAR (d) Antenna
Answer:
(a) LASER

Question 28.
The Dimension of Rydberg is constant
(a) [M° L^-1 T°] (b) [M°L°T^-1] (c) [M° LF^-1] (d) [ML² T^-1]
Answer:

Question 29.
Solar cell is used in
(a) Artificial satellite (b) On the moon (c) Mars (d) None of these
Answer:
(a) Artificial satellite

Question 30.
A transistor behaves as a switch
(a) In Active region (b) cut off state (c) s (d) b and c both
Answer:
(d) b and c both

Question 31.
A uniform magnetic field is obtained in
(a) A bar magnet (b) A horse-shoe magnet (c) A circular coil carrying current (d) A cylindrical coil carrying a current.
Answer:
(b) A horse-shoe magnet

Question 32.
Boolean expression of AND gate is
(a) \(\overline{A \cdot B}=y\) (b) A + B = y (c) A – B = y (d) A + B = y
Answer:
(c)

Question 33.
In long-distance radio-broadcast short wave bands are used because
(a) Ionosphere reflects these (b) Ionosphere transmits these (c) Ionosphere absorbs these (d) None of these
Answer:
(a) Ionosphere reflects these

Question 34.
The process which works as modulator and de-modulator is called
(a) Laser (b) RADAR (c) Modem (d) Fax
Answer:
(c) Modem

Question 35.
The message superposed on carrier wave is called
(a) Transmission (b) Modulation (c) Demoduletion (d) Transducer
Answer:
(b) Modulation

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 surface density of charge? Write its S.I. unit.
Answer:
The amount of electric charge per unit surface area is called surface density of charge.
It is denoted by σ.
\(\sigma=\frac{Q}{A}\)
The S.I. Unit of surface density of charge is Coulomb/m².

Question 2.
A electric dipole is placed in electric field 4 x 10⁴ volt/m making an angle 30°. The torque 1.6 x 10^-25 Nm volt m the dipole. Calculate electric dipole moment.
Answer:

Question 3.
Write the uses of Cyclotrons.
Answer:
There are many uses of cyclotrons :

• Cyclotrons are used to treat cancer.
• Ion Beams from cyclotrons can be used, are in proton therapy, to penetrate the body and kill tumors by radiation damage.
• Cyclotrons are used to achieve required velocity of a bombarding particle in nuclear reaction.

Question 4.
What is Shunt?
Answer:
A Shunt is a low resistance wire which allows electric current to pass around another point in the circuit by creating a low resistance path.

It is added in parallel with Galvanometer.

Question 5.
What is ampere’s circuited law with expression?
Answer:
It states that the line integral of magnetic field
\(\overrightarrow{(B)}\) around any closed path are, circuit is equal to p0 times of total current (I) threading the closed circuit.

where, μ₀ = permeability of free space.

Question 6.
Why core of transformer is laminated ?
Answer:
The wire of transformer is laminated so as to reduce loss of energy due to eddy currents. The magnitude and eddy currents set up is considerably minimised when the core is laminated.

Question 7.
What are the properties of electro-magnetic wave ?
Answer:

• These wave does not need material medium for propagation.
• These wave obeys principle of superposition of charge.
• These wave moves in vacuum or in air with velocity of light.
  \(\frac{1}{\sqrt{\mu_{0} \varepsilon_{0}}} \geq C=3 \times 10^{8} \mathrm{m} / \mathrm{s}\)
• The ratio of amplitude of electric field and magnetic field remains constant and it is equal to velocity of light.
  \(\frac{E}{B}=C\)

Question 8.
A uniform magnetic field gets modified as shown in the figure, when two specimens X and Y are placed in it.

(i) Identify the two specimensx andy.
(ii) State the reason for modification of the field lines in x andy.
Answer:

1. X is diamagenetic and Y is ferromagnetic.
2. Diamagnetic materials have permeabilities less than I (one) and have negative susceptibility. Their atoms and molecules do not have permanent dipole moment. The field lines get expelled in them. Ferromagnetic materials have permeability more than one and susceptibility positive. Their atoms and molecules have permanent dipole moment. So the field lines get concentrated in them.

Question 9.
What is the importance of radial magnetic field in moving coil Galvanometer ?
Answer:
When the magnetic field is made radial by using a field magnet with concave poles, the plane of coil always remains parallel to the direction of magnetic field. Due to this, the galvanometer scale becomes linear.

Question 10.
Why does the colour of the oil film on the surface of water continuously changes ?
Answer:
The location of bright and dark fringes produced by thin oil films depends upon the thickness of the film. The thickness of oil film on the surface of water continuously varies and as a result, the position of coloured fringes also varies. This appears as a variation in the colour of oil films.

Question 11.
Two coherent sources whose intensity ratio is 25 : 4 produces interference fringes. Calculate the ratio of intensity of maxima and minima in the fringe system.
Answer:

Question 13.
Write logic symbol and truth table of NOR
Answer:
Symbol.

Question 14.
Write two characteristics of LASER rays.
Answer:

• It is highly directional with parallel beam.
• It is monochromatic and coherent.

Question 15.
What do you mean by analog and digital signal.
Answer:
Analog signal :
It is an electrical wave form continuously changing in magnitude with time.

Digital signalI :
is a discontinuous and decrease signal having only binary variation between 1 and 0 with time.

Question 16.
Show that de-Broglie wave length of electron of energy E is given by relation
\(\lambda=\frac{h}{\sqrt{2 m E}}\)
(b) Why is the belt of Vandergrift Generator made of insulating material ?
Answer:
Consider that an electron of mass m and charge e is accelerated through a potential difference V. If E is the energy, then

(b) Belt of a Vandegrift generator is made of insulating material because the charge it receives remain fixed on its surface and carries upto the dome.

Question 17.
What are the differences between polarised and unpolarised light.
Answer:
Polarised light:

• The light waves that have vibration occuring within them in a single plane.
• Only takes place with the help of sunlight.

Unpolorised light:

• The light waves that have vibration occuring within them of random angles without any plane.
• Reflection is scattering or travel through a material that can cause polarisation.

Question 18.
Define half life, mention the relation between half life and decay constant.
Answer:
Half Life :
The half life of a radioa ctive is the time in which the no. of radio active atoms of the substance is reduced to half of its original value.

Relation :
We know that λ + N = N₀e^-λ

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.
What is capacitor? Find the expression for equivalent capacity when three capacitor are joined in series.
Answer:
Capacitor :
The artificial arrangement of conductor in which capacity of conductor increases by decreasing potential.

Expression for equivalent capacity

Let A₁ B₁, A₂ B₂ and A₃ B₃ are three capacitor grouped in series whose capacity are C₁, C₂ and C₃ respectively.

In the series grouping charge is same on all capacitor but potential is different. Its V₁, V₂ and V₃ are potentials then

Thus in series grouping, reciprocal of equivalent capacity is equal to algebraic sum of reciprocals of individual capacity.

Question 20.
Explain how the average velocity of free electrons in the metal at constant temperature, in an electric field remains constant even though the electrons are being constantly accelerated by this electric field.
Answer:
Consider a metallic conductor XY of length / and cross-sectional area A. A potential difference V is applied across the conductor XT. Due to this potential difference in electric field \(\vec{E}\) is produced in the conductor. The magnitude of electric field strength \(E=\vec{l}\) and its direction is from Y to X. This electric field exerts a force on free electrons; due to which electrons are accelerated.

The electric force on electron \(\vec{F}=-e \vec{E}\) (where e = + 1.5 x 10^-9 coulomb).

If m is the mass of electron, then its acceleration
\(\vec{a}=\frac{\vec{F}}{m}=-\frac{e \vec{E}}{m}\) ……………….. (i)

This acceleration remains constant only for a very short duration, since there are random forces which deflect the electron in random manner. These deflections may arise due to

• ions of metallic crystal vibrate simple narratically around their mean positions. Different ions vibrate in different directions and may be displaced by different amounts.
• direct collisions of electrons with atoms of metallic crystal lattice.
• In any way after a short duration it called relaxation time the motion of electrons become random.

Thus, we can imagine that the electrons are accelerated only for a short duration. As average velocity of random motion is zero, if we consider the average motion of an electron. Then its initial velocity is zero, so the velocity of electron after time τ (i.e., drift velocity \(\vec{y}\) (d) is given by the relation.

At given temperature, the relaxation time τ remains constant, so drift velocity remains constant.

Question 21.
What do you mean by mutual inductance of two nearby coils ? Find an expression for Mutual Inductance of two co-exial solenoid.
Answer:
When current flowing in one of two nearby coil is changed, the magnetic flux linked with the other coil changes; due to which an emf is induced in it (other coil). This phenemenon of electromagnetic induction is called the mutual induction. The coil, in which current is changed is called the primary coil and the coil in which emf is induced is called the secondary coil.

The S.I. unit of mutual inductnace is Henry.

Mutual Inductance :
Suppose there are two coils C₁ and C₂. The current l₁ is flowing in primary coil C₁ due to which an effective magnetic flux Φ₂ is linked with secondary coil C₂. By experiments
\(\Phi_{2} \propto I_{1} \text { or } \Phi_{2}=M l_{1}\) ……………….(i)

where M is a constant, and is called the coefficient of mutual induction or mutual inductance.

From (i)
\(\begin{aligned}
&M=\frac{\phi_{2}}{I_{1}}\\
&\text { If } I_{1}=\text { ampere, } M=\phi_{2}
\end{aligned}\)

i.e., the mutual inductance between two coils is numerically equal to the effective flux linked with secondary coil when current flowing in primary coil is ampere.

Mutual Inductance of Two Co-axial Solenoids :
Consider two long co-axial solenoid each of length l with number of turns Nx and N2 wound one over the other. Number of turns per unit length in order (primary) solenoid,

\(n=\frac{N_{1}}{l}\). If l₁, is the current flowing in primary solenoid, the magnetic field produced with this solenoid.
\(B_{1}=\frac{\mu_{0} N_{1} l_{1}}{l}\) …………………… (ii)

The flux linked with each turn of inner solenoid coil is Φ₂ = B₁ A₂. where A₂ is the cross-sectional area of inner solenoid. The total flux linkage with inner coil of N₂-turns.

By definition Mutual Inductance,

If n₁ is number of turns per unit length of outer solenoid and r₂ is radius of inner solenoid, then M = μ₀n N₂πr_2^2.

Question 22.
Derive expression for self inductance of a long air-cored solenoid of length l, cross-sectional area A and having number of turns N.
Answer:
Self Inductance of a long air-cored solenoid :
Consider a long air solenoid having’ri number of turns per unit length. If current in solenoid is /, then magnetic field within the solenoid,

B = μ₀nl ………………(i)

where μ₀ = 4π x 10^-7 Henry/metre is the permeability of free space.

If A is cross-sectional area of solenoid then effective flux linked with solenoid or length T : Φ = NBA where N = ill is the number of turns in length l of solenoid.

Remark :
If solenoid contains a core of ferromagnetic substance of relative permeability μ₀ then self inducatance,
\(L=\frac{\mu_{r} \mu_{0} N^{2} A}{l}\)

Question 23.
Define Alternating Current. Establish the relation between mis value of virtual value and peak value of alternating current.
Answer:
Alternating current (A.C.)-The current in the coil flows in one direction and for the other half of the period. The current flows in the reverse direction. Such a current is called the alternating current, or A.C. It is shown in following graph.
It is given by l = l₀ (ωt + Φ)
where l₀ = current amplitude
t = time period
\(\omega=\frac{2 \pi}{T}\)

• Peak value-/0 is called peak value of Alternating current.
• Root mean square value of AC (RMS)-RMS value is also called virtual value of effective value of AC is that steady current which would produce some heat in given resistance in given time as is done by the alternating current when passed through the same resistance for the same time.

Let the Alternating current, T = l₀ sin ωt
Let dθ be the heat produced by this current in resistance R is an infinitesimally small dt.

Then dθ= I² Rclt

The total quantity of heat produced over one complete cycle of alternating current is given by

The virtual value of alternating current is 0.707 times the peak value of alternating current.

Question 24.
Verify the law of reflection on the basis of Hygienic wave theory of light.
Verification of law of reflection on the basis of wave theory.
Answer:
Let XY be reflecting surface and PA be a plane wave front just incident on the surface. The normals LA and MP to the wave point represents incident rays. If AN is normal to the reflecting surface at a then ∠NAL = i.

The plane wave point reaches at point A and P’ Later in time but in this order. So that it will reach point P in the lost. When the disturbance from point P just reachs point P1 on the reflecting surface, the secondary wavelets from point A on one reflecting surface will grow into sphere of radius AA’ such that AA’ = PP.

Consider any point Q on the incident wave front, Suppose that when disturbance from point P on incident wave front reaches P\ the disturbance from point Q reaches Q’ via point K on the reflecting surface. Since, P’A’ represents the reflected wave front, the time taken by light to travel from any point on incident wave front to the corresponding point. If C is the velocity of light, then time taken by light to go from point Q to Q’ is given by

For rays different points on the incident wave front, the value Q AK are different. The rays from different points on incident wave point will take some time to reach the corresponding points on the reflected wave points. If t given by eq”, (ii) is independent of AK. It follows that

AK (sin i – sin r) should be zero
sin i = sin r = 0
sin i = sin r
i = r
The angle of incidence = Angle of reflection.

Bihar Board 12th Maths Objective Questions and Answers

Bihar Board 12th Maths Objective Answers Chapter 1 Relations and Functions

Question 1.
If R = {(x, y) : x, y ∈ I, x² + y² ≤ 4} is a relation in I, then domain of R is
(a) {0, 1, 2}
(b) {-2, -1, 0}
(c) {-2, -1, 0, 2}
(d) None of these
Answer:
(c) {-2, -1, 0, 2}

Question 2.
If A = {1, 2, 3}, B = {1, 4, 6, 9} and R is relation from A to B defined by ‘or is greater thany’. The range of R is
(a) {1, 4, 6, 9}
(b) {4, 6, 9}
(c) {1}
(d) None of these
Answer:
(c) {1}

Question 3.
The relation R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3), (1, 3)} on set A = {1, 2, 3} is
(a) Reflexive but not symmetric
(b) Reflexive but not transitive
(c) Symmetric and transitive
(d) Neither symmetric nor transitive
Answer:
(a) Reflexive but not symmetric

Question 4.
Let P = {(x, y) | x² + y² = 1, xy ∈ R}. Then P is
(a) Reflexive
(b) Symmetric
(c) Transitive
(d) Anti-symmetric
Answer:
(b) Symmetric

Question 5.
Let S be the set of all real numbers. Then, the relation R = {(a, b) : 1 + ab > 0} on S is
(a) Reflexive and symmetric but not transitive
(b) Reflexive and transitive but not symmetric
(c) Symmetric and transitive but not reflexive
(d) Reflexive, transitive and symmetric
Answer:
(a) Reflexive and symmetric but not transitive

Question 6.
Let R be a relation on the set N be defined by {(x, y) | x, y ∈ N, 2x + y = 41}. Then, R is
(a) Reflexive
(b) Symmetric
(c) Transitive
(d) None of these
Answer:
(d) None of these

Question 7.
Let R be the relation on the set of all real numbers defined by aRb iff |a – b| ≤ 1. Then, R is
(a) Reflexive and symmetric
(b) Symmetric only
(c) Transitive only
(d) Anti-symmetric only
Answer:
(a) Reflexive and symmetric

Question 8.
If R and R’ are symmetric relations (not disjoint) on a set A, then the relation R ∩ R’ is
(a) Reflexive
(b) Symmetric
(c) Transitive
(d) None of these
Answer:
(b) Symmetric

Question 9.
Let A = {1, 2, 3, 4} and R be a relation in A given by R = {(1, 1), (2, 2), (3, 3), (4, 4), (1, 2), (2, 1), (3, 1). Then, R is
(a) Reflexive
(b) Transitive
(c) An equivalence relation
(d) None of these
Answer:
(a) Reflexive

Question 10.
Which one of the following relations on R is an equivalence relation?
(a) aR₁b ⇔ |a| = |b|
(b) aR₂b ⇔ a ≥ b
(c) aR₃b ⇔ a divides b
(d) aR₄b ⇔ a < b
Answer:
(a) aR₁b ⇔ |a| = |b|

Question 11.
Let R be a relation on the set N of natural numbers denoted by nRm ⇔ n is a factor of m (i.e. n | m). Then, R is
(a) Reflexive and symmetric
(b) Transitive and symmetric
(c) Equivalence
(d) Reflexive, transitive but not symmetric
Answer:
(d) Reflexive, transitive but not symmetric

Question 12.
Let S = {1, 2, 3, 4, 5} and let A = S × S. Define the relation R on A as follows:
(a, b) R (c, d) iff ad = cb. Then, R is
(a) reflexive only
(b) Symmetric only
(c) Transitive only
(d) Equivalence relation
Answer:
(d) Equivalence relation

Question 13.
Let R be the relation “is congruent to” on the set of all triangles in a plane is
(a) reflexive
(b) symmetric
(c) symmetric and reflexive
(d) equivalence
Answer:
(d) equivalence

Question 14.
Total number of equivalence relations defined in the set S = {a, b, c} is
(a) 5
(b) 3!
(c) 23
(d) 33
Answer:
(a) 5

Question 15.
The relation R is defined on the set of natural numbers as {(a, b) : a = 2b}. Then, R^-1 is given by
(a) {(2, 1), (4, 2), (6, 3),….}
(b) {(1, 2), (2, 4), (3, 6), ……..}
(c) R^-1 is not defiend
(d) None of these
Answer:
(b) {(1, 2), (2, 4), (3, 6), ……..}

Question 16.
The domain of the function \(f(x)=\frac{1}{\sqrt{\{\sin x\}+\{\sin (\pi+x)\}}}\) where {.} denotes fractional part, is
(a) [0, π]
(b) (2n + 1) π/2, n ∈ Z
(c) (0, π)
(d) None of these
Answer:
(d) None of these

Question 17.
Range of \(f(x)=\sqrt{(1-\cos x) \sqrt{(1-\cos x) \sqrt{(1-\cos x) \ldots \ldots \infty}}}\)
(a) [0, 1]
(b) (0, 1)
(c) [0, 2]
(d) (0, 2)
Answer:
(c) [0, 2]

Question 18.
Consider the function y = f(x) satisfying the condition \(f\left(x+\frac{1}{x}\right)=x^{2}+\frac{1}{x^{2}}(x \neq 0)\). Then which of the
following is not true?
(a) Domain of f(x) is (-∞, -2] ∪ [2, ∞)
(b) f(x) is an even function
(c) Range of f(x) is [2, ∞)
(d) None of these
Answer:
(d) None of these

Question 19.
The function f : R → R defined by f(x) = 6x + 6 |x| is
(a) One-one and onto
(b) Many-one and onto
(c) One-one and into
(d) Many-one and into
Answer:
(c) One-one and into

Question 20.
f : N → N where f(x) = x – (-1)^x, then f is
(a) One-one and into
(b) Many-one and into
(c) One-one and onto
(d) Many-one and onto
Answer:
(c) One-one and onto

Question 21.
A function f from the set of natural numbers to integers is defined by

(a) one-one but not onto
(b) onto but not one-one
(c) one-one and onto both
(d) neither one-one nor onto
Answer:
(c) one-one and onto both

Question 22.
Let X = {-1, 0, 1}, Y = {0, 2} and a function f : X → Y defiend by y = 2x⁴, is
(a) one-one onto
(b) one-one into
(c) many-one onto
(d) many-one into
Answer:
(c) many-one onto

Question 23.
Let f : R → R be a function defined by \(f(x)=\frac{e^{|x|}-e^{-x}}{e^{x}+e^{-x}}\) then f(x) is
(a) one-one onto
(b) one-one but not onto
(c) onto but not one-one
(d) None of these
Answer:
(d) None of these

Question 24.
Let g(x) = x² – 4x – 5, then
(a) g is one-one on R
(b) g is not one-one on R
(c) g is bijective on R
(d) None of these
Answer:
(b) g is not one-one on R

Question 25.
Let A = R – {3}, B = R – {1}. Let f : A → B be defined by \(f(x)=\frac{x-2}{x-3}\). Then,
(a) f is bijective
(b) f is one-one but not onto
(c) f is onto but not one-one
(d) None of these
Answer:
(a) f is bijective

Question 26.
The mapping f : N → N is given by f(n) = 1 + n², n ∈ N when N is the set of natural numbers is
(a) one-one and onto
(b) onto but not one-one
(c) one-one but not onto
(d) neither one-one nor onto
Answer:
(c) one-one but not onto

Question 27.
The function f : R → R given by f(x) = x³ – 1 is
(a) a one-one function
(b) an onto function
(c) a bijection
(d) neither one-one nor onto
Answer:
(c) a bijection

Question 28.
Let f : [0, ∞) → [0, 2] be defined by \(f(x)=\frac{2 x}{1+x}\), then f is
(a) one-one but not onto
(b) onto but not one-one
(c) both one-one and onto
(d) neither one-one nor onto
Answer:
(a) one-one but not onto

Question 29.
If N be the set of all-natural numbers, consider f : N → N such that f(x) = 2x, ∀ x ∈ N, then f is
(a) one-one onto
(b) one-one into
(c) many-one onto
(d) None of these
Answer:
(b) one-one into

Question 30.
Let A = {x : -1 ≤ x ≤ 1} and f : A → A is a function defined by f(x) = x |x| then f is
(a) a bijection
(b) injection but not surjection
(c) surjection but not injection
(d) neither injection nor surjection
Answer:
(a) a bijection

Question 31.
Let f : R → R be a function defined by f(x) = x³ + 4, then f is
(a) injective
(b) surjective
(c) bijective
(d) none of these
Answer:
(c) bijective

Question 32.
The function f : A → B defined by f(x) = 4x + 7, x ∈ R is
(a) one-one
(b) Many-one
(c) Odd
(d) Even
Answer:
(a) one-one

Question 33.
The smallest integer function f(x) = [x] is
(a) One-one
(b) Many-one
(c) Both (a) & (b)
(d) None of these
Answer:
(b) Many-one

Question 34.
The function f : R → R defined by f(x) = 3 – 4x is
(a) Onto
(b) Not onto
(c) None one-one
(d) None of these
Answer:
(a) Onto

Question 35.
The number of bijective functions from set A to itself when A contains 106 elements is
(a) 106
(b) (106)²
(c) 106!
(d) 2¹⁰⁶
Answer:
(c) 106!

Question 36.
If f(x) = (ax² + b)³, then the function g such that f(g(x)) = g(f(x)) is given by
(a) \(g(x)=\left(\frac{b-x^{1 / 3}}{a}\right)\)
(b) \(g(x)=\frac{1}{\left(a x^{2}+b\right)^{3}}\)
(c) \(g(x)=\left(a x^{2}+b\right)^{1 / 3}\)
(d) \(g(x)=\left(\frac{x^{1 / 3}-b}{a}\right)^{1 / 2}\)
Answer:
(d) \(g(x)=\left(\frac{x^{1 / 3}-b}{a}\right)^{1 / 2}\)

Question 37.
If f : R → R, g : R → R and h : R → R is such that f(x) = x², g(x) = tanx and h(x) = logx, then the value of [ho(gof)](x), if x = \(\frac{\sqrt{\pi}}{2}\) will be
(a) 0
(b) 1
(c) -1
(d) 10
Answer:
(a) 0

Question 38.
If f : R → R and g : R → R defined by f(x) = 2x + 3 and g(x) = x² + 7, then the value of x for which f(g(x)) = 25 is
(a) ±1
(b) ±2
(c) ±3
(d) ±4
Answer:
(b) ±2

Question 39.
Let the functions f, g, h are defined from R to R such that

ho(fog)(x) is defined by
(a) x
(b) x²
(c) 0
(d) none of these
Answer:
(b) x²

Question 40.

(a) 1
(b) -1
(c) √3
(d) 0
Answer:
(b) -1

Question 41.
Let f : N → R : f(x) = \(\frac{(2 x-1)}{2}\) and g : Q → R : g(x) = x + 2 be two functions. Then, (gof) (\(\frac{3}{2}\)) is
(a) 3
(b) 1
(c) \(\frac{7}{2}\)
(d) None of these
Answer:
(a) 3

Question 42.
Let \(f(x)=\frac{x-1}{x+1}\), then f(f(x)) is
(a) \(\frac{1}{x}\)
(b) \(-\frac{1}{x}\)
(c) \(\frac{1}{x+1}\)
(d) \(\frac{1}{x-1}\)
Answer:
(b) \(-\frac{1}{x}\)

Question 43.
If f(x) = \(1-\frac{1}{x}\), then f(f(\(\frac{1}{x}\)))
(a) \(\frac{1}{x}\)
(b) \(\frac{1}{1+x}\)
(c) \(\frac{x}{x-1}\)
(d) \(\frac{1}{x-1}\)
Answer:
(c) \(\frac{x}{x-1}\)

Question 44.
If f : R → R, g : R → R and h : R → R are such that f(x) = x², g(x) = tan x and h(x) = log x, then the value of (go(foh)) (x), if x = 1 will be
(a) 0
(b) 1
(c) -1
(d) π
Answer:
(a) 0

Question 45.
If f(x) = \(\frac{3 x+2}{5 x-3}\) then (fof)(x) is
(a) x
(b) -x
(c) f(x)
(d) -f(x)
Answer:
(a) x

Question 46.
If f(x) = (ax² – b)³, then the function g such that f{g(x)} = g{f(x)} is given by
(a) \(g(x)=\left(\frac{b-x^{1 / 3}}{a}\right)^{1 / 2}\)
(b) \(g(x)=\frac{1}{\left(a x^{2}+b\right)^{3}}\)
(c) \(g(x)=\left(a x^{2}+b\right)^{1 / 3}\)
(d) \(g(x)=\left(\frac{x^{1 / 3}+b}{a}\right)^{1 / 2}\)
Answer:
(d) \(g(x)=\left(\frac{x^{1 / 3}+b}{a}\right)^{1 / 2}\)

Question 47.
If f : [1, ∞) → [2, ∞) is given by f(x) = x + \(\frac{1}{x}\), then f^-1 equals to
(a) \(\frac{x+\sqrt{x^{2}-4}}{2}\)
(b) \(\frac{x}{1+x^{2}}\)
(c) \(\frac{x-\sqrt{x^{2}-4}}{2}\)
(d) \(1+\sqrt{x^{2}-4}\)
Answer:
(a) \(\frac{x+\sqrt{x^{2}-4}}{2}\)

Question 48.
Let f(x) = x² – x + 1, x ≥ \(\frac{1}{2}\), then the solution of the equation f(x) = f^-1(x) is
(a) x = 1
(b) x = 2
(c) x = \(\frac{1}{2}\)
(d) None of these
Answer:
(a) x = 1

Question 49.
Which one of the following function is not invertible?
(a) f : R → R, f(x) = 3x + 1
(b) f : R → [0, ∞), f(x) = x²
(c) f : R⁺ → R⁺, f(x) = \(\frac{1}{x^{3}}\)
(d) None of these
Answer:
(d) None of these

Question 50.
The inverse of the function \(y=\frac{10^{x}-10^{-x}}{10^{x}+10^{-x}}\) is
(a) \(\log _{10}(2-x)\)
(b) \(\frac{1}{2} \log _{10}\left(\frac{1+x}{1-x}\right)\)
(c) \(\frac{1}{2} \log _{10}(2 x-1)\)
(d) \(\frac{1}{4} \log \left(\frac{2 x}{2-x}\right)\)
Answer:
(b) \(\frac{1}{2} \log _{10}\left(\frac{1+x}{1-x}\right)\)

Question 51.
If f : R → R defind by f(x) = \(\frac{2 x-7}{4}\) is an invertible function, then find f^-1.
(a) \(\frac{4 x+5}{2}\)
(b) \(\frac{4 x+7}{2}\)
(c) \(\frac{3 x+2}{2}\)
(d) \(\frac{9 x+3}{5}\)
Answer:
(b) \(\frac{4 x+7}{2}\)

Question 52.
Consider the function f in A = R – {\(\frac{2}{3}\)} defiend as \(f(x)=\frac{4 x+3}{6 x-4}\). Find f^-1.
(a) \(\frac{3+4 x}{6 x-4}\)
(b) \(\frac{6 x-4}{3+4 x}\)
(c) \(\frac{3-4 x}{6 x-4}\)
(d) \(\frac{9+2 x}{6 x-4}\)
Answer:
(a) \(\frac{3+4 x}{6 x-4}\)

Question 53.
If f is an invertible function defined as f(x) = \(\frac{3 x-4}{5}\), then f^-1(x) is
(a) 5x + 3
(b) 5x + 4
(c) \(\frac{5 x+4}{3}\)
(d) \(\frac{3 x+2}{3}\)
Answer:
(c) \(\frac{5 x+4}{3}\)

Question 54.
If f : R → R defined by f(x) = \(\frac{3 x+5}{2}\) is an invertible function, then find f^-1.
(a) \(\frac{2 x-5}{3}\)
(b) \(\frac{x-5}{3}\)
(c) \(\frac{5 x-2}{3}\)
(d) \(\frac{x-2}{3}\)
Answer:
(a) \(\frac{2 x-5}{3}\)

Question 55.
Let f : R → R, g : R → R be two functions such that f(x) = 2x – 3, g(x) = x³ + 5. The function (fog)^-1 (x) is equal to
(a) \(\left(\frac{x+7}{2}\right)^{1 / 3}\)
(b) \(\left(x-\frac{7}{2}\right)^{1 / 3}\)
(c) \(\left(\frac{x-2}{7}\right)^{1 / 3}\)
(d) \(\left(\frac{x-7}{2}\right)^{1 / 3}\)
Answer:
(d) \(\left(\frac{x-7}{2}\right)^{1 / 3}\)

Question 56.
Let * be a binary operation on set of integers I, defined by a * b = a + b – 3, then find the value of 3 * 4.
(a) 2
(b) 4
(c) 7
(d) 6
Answer:
(c) 7

Question 57.
If * is a binary operation on set of integers I defined by a * b = 3a + 4b – 2, then find the value of 4 * 5.
(a) 35
(b) 30
(c) 25
(d) 29
Answer:
(b) 30

Question 58.
Let * be the binary operation on N given by a * b = HCF (a, b) where, a, b ∈ N. Find the value of 22 * 4.
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2

Question 59.
Consider the binary operation * on Q defind by a * b = a + 12b + ab for a, b ∈ Q. Find 2 * \(\frac{1}{3}\)
(a) \(\frac{20}{3}\)
(b) 4
(c) 18
(d) \(\frac{16}{3}\)
Answer:
(a) \(\frac{20}{3}\)

Question 60.
Consider a binary operation * on the set {1, 2, 3, 4, 5} given by the following multiplication table. Compute (2 * 3) * (4 * 5).

(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(a) 1

Question 61.
If the binary operation * is defind on the set Q+ of all positive rational numbers by a * b = \(\frac{a b}{4}\). Then, \(3 *\left(\frac{1}{5} * \frac{1}{2}\right)\) is equal to
(a) \(\frac{3}{160}\)
(b) \(\frac{5}{160}\)
(c) \(\frac{3}{10}\)
(d) \(\frac{3}{40}\)
Answer:
(a) \(\frac{3}{160}\)

Question 62.
The number of binary operations that can be defined on a set of 2 elements is
(a) 8
(b) 4
(c) 16
(d) 64
Answer:
(c) 16

Question 63.
Let * be a binary operation on Q, defined by a * b = \(\frac{3 a b}{5}\) is
(a) Commutative
(b) Associative
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 64.

(a) 0
(b) 1
(c) 2
(d) 3
Answer:
(a) 0

Question 65.
Let * be a binary operation on set Q of rational numbers defined as a * b = \(\frac{a b}{5}\). Write the identity for *.
(a) 5
(b) 3
(c) 1
(d) 6
Answer:
(a) 5

Question 66.
For binary operation * defind on R – {1} such that a * b = \(\frac{a}{b+1}\) is
(a) not associative
(b) not commutative
(c) commutative
(d) both (a) and (b)
Answer:
(d) both (a) and (b)

Question 67.
The binary operation * defind on set R, given by a * b = \(\frac{a+b}{2}\) for all a,b ∈ R is
(a) commutative
(b) associative
(c) Both (a) and (b)
(d) None of these
Answer:
(a) commutative

Question 68.
Let A = N × N and * be the binary operation on A defined by (a, b) * (c, d) = (a + c, b + d). Then * is
(a) commutative
(b) associative
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 69.
Find the identity element in the set I⁺ of all positive integers defined by a * b = a + b for all a, b ∈ I⁺.
(a) 1
(b) 2
(c) 3
(d) 0
Answer:
(d) 0

Question 70.
Let * be a binary operation on set Q – {1} defind by a * b = a + b – ab : a, b ∈ Q – {1}. Then * is
(a) Commutative
(b) Associative
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 71.
The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is
(a) commutative only
(b) associative only
(c) both commutative and associative
(d) none of these
Answer:
(c) both commutative and associative

Question 72.
The number of commutative binary operation that can be defined on a set of 2 elements is
(a) 8
(b) 6
(c) 4
(d) 2
Answer:
(d) 2

Question 73.
Let T be the set of all triangles in the Euclidean plane, and let a relation R on T be defined as aRb if a is congruent to b ∀ a, b ∈ T. Then R is
(a) reflexive but not transitive
(b) transitive but not symmetric
(c) equivalence
(d) None of these
Answer:
(c) equivalence

Question 74.
The maximum number of equivalence relations on the set A = {1, 2, 3} are
(a) 1
(b) 2
(c) 3
(d) 5
Answer:
(d) 5

Question 75.
Let us define a relation R in R as aRb if a ≥ b. Then R is
(a) an equivalence relation
(b) reflexive, transitive but not symmetric
(c) symmetric, transitive but not reflexive
(d) neither transitive nor reflexive but symmetric
Answer:
(b) reflexive, transitive but not symmetric

Question 76.
Let A = {1, 2, 3} and consider the relation R = {(1, 1), (2, 2), (3, 3), (1, 2), (2, 3), (1, 3)}. Then R is
(a) reflexive but not symmetric
(b) reflexive but not transitive
(c) symmetric and transitive
(d) neither symmetric, nor transitive
Answer:
(a) reflexive but not symmetric

Question 77.
The identity element for the binary operation * defined on Q – {0} as a * b = \(\frac{a b}{2}\) ∀ a, b ∈ Q – {0) is
(a) 1
(b) 0
(c) 2
(d) None of these
Answer:
(c) 2

Question 78.
Let A = {1, 2, 3, …. n} and B = {a, b}. Then the number of surjections from A into B is
(a) \(^{n} P_{2}\)
(b) 2ⁿ – 2
(c) 2ⁿ – 1
(d) none of these
Answer:
(b) 2ⁿ – 2

Question 79.
Let f : R → R be defind by f(x) = \(\frac{1}{x}\) ∀ x ∈ R. Then f is
(a) one-one
(b) onto
(c) bijective
(d) f is not defined
Answer:
(d) f is not defined

Question 80.
Which of the following functions from Z into Z are bijective?
(a) f(x) = x³
(b) f(x) = x + 2
(c) f(x) = 2x + 1
(d) f(x) = x² + 1
Answer:
(b) f(x) = x + 2

Question 81.
Let f : R → R be the functions defined by f(x) = x³ + 5. Then f^-1(x) is
(a) \((x+5)^{\frac{1}{3}}\)
(b) \((x-5)^{\frac{1}{3}}\)
(c) \((5-x)^{\frac{1}{3}}\)
(d) 5 – x
Answer:
(b) \((x-5)^{\frac{1}{3}}\)

Question 82.
Let f : R – {\(\frac{3}{5}\)} → R be defined by f(x) = \(\frac{3 x+2}{5 x-3}\). Then
(a) f^-1(x) = f(x)
(b) f^-1(x) = -f(x)
(c) (fof) x = -x
(d) f^-1(x) = \(\frac{1}{19}\) f(x)
Answer:
(a) f^-1(x) = f(x)

Question 83.
Let f : [0, 1] → [0, 1] be defined by

(a) constant
(b) 1 + x
(c) x
(d) None of these
Answer:
(c) x

Question 84.

(a) 9
(b) 14
(c) 5
(d) None of these
Answer:
(a) 9

Question 85.
Let f : R → R be given by f(x) = tan x. Then f^-1(1) is
(a) \(\frac{\pi}{4}\)
(b) {nπ + \(\frac{\pi}{4}\); n ∈ Z}
(c) Does not exist
(d) None of these
Answer:
(b) {nπ + \(\frac{\pi}{4}\); n ∈ Z}

Bihar Board 12th Physics Model Papers

Bihar Board 12th Physics Model Question Paper 4 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.

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.
Coulomb force is
(a) Central force
(b) Electric force
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 2.
The property of circuit by which electrical energy changes into heat energy is called
(a) Resistance
(b) Current
(c) Voltage
(d) Electromotive force
Answer:
(a) Resistance

Question 3.
If P, Q, R and S are sides of Wheatstone Bridge then in a balanced state
(a) P + Q = R + S
\(\text { (b) } \frac{P}{Q}=\frac{R}{S}\)
\(\text { (c) } \mathrm{QP}=\frac{\mathrm{S}}{\mathrm{R}}\)
(d) None of these
Answer:
\(\text { (b) } \frac{P}{Q}=\frac{R}{S}\)

Question 4.
When temperature of metal increases, its resistance
(a) increases
(b) decreases
(c) remains constant
(d) none of these
Answer:
(a) increases

Question 5.
The resistance of ideal voltmeter is
(a) infinity
(b) zero
(c) 50000 Ω
(d) none of these
Answer:
(a) infinity

Question 6.
Two particles A and B having equal charge after being acceserated through the same potential difference enter a region of uniform magnetic field and describe circular path of radius Rj and R2. The ratio of mass A to that of B is

Answer:
(c)

Question 7.
Ampere is unit of
(a) Power
(b) Current
(c) Energy
(d) Potential
Answer:
(b) Current

Question 8.
The S.I. unit of magnetic flux is
(a) Tesla
(b) Henry
(c) Weber
(d) Joule-sec
Answer:
(c) Weber

Question 9.
The working principle of Dynamo is based on
(a) Heating effect of current
(b) Electromagnetic induction
(c) On induced magnetism
(d) On induced current
Answer:
(b) Electromagnetic induction

Question 10.
The hot wire Ammeter measure value of Alternating current
(a) Peak value
(b) Average value
(c) rms value
(d) None of these
Answer:
(b) Average value

Question 11.
Which substance is suitable to made the core of transformer ?
(a) soft iron
(b) copper
(c) stainless steel
(d) Alnico
Answer:
(a) soft iron

Question 12.
The value of current decreases from 5A to OA in 0.1 sec. If induced emf is 200 V then value of self inductance is
(a) 4H
(b) 3H
(c) 4m H
(d) 3mH
Answer:
(a) 4H

Question 13.
The change in magnetic field with time at a point produces
(a) Gravitational field
(b) Magnetic field
(c) Electric field
(d) None of these
Answer:
(c) Electric field

Question 14.
Which have maximum penetrating power ?
(a) X-ray
(b) Cathode ray
(c) cc-fay
(d) y-ray
Answer:
(d) y-ray

Question 15.
A spherical mirror is immersed in water. Its focal length
(a) Increases
(b) Decreases
(c) Remains constant
(d) None of these
Answer:
(c) Remains constant

Question 16.
A light rays goes from glass \(\left(\mu=\frac{5}{3}\right)\) to water \(\left(\mu=\frac{4}{3}\right)\) Its critical angle will

Answer:
(b)

Question 17.
The optical fibre works on the principle of
(a) scattering
(b) retraction
(c) dispersion
(d) total internal reflection
Answer:
(d) total internal reflection

Question 18.
The unit of power of lens is
(a) Lambda
(b) Candela
(c) Dioptre
(d) Watt
Answer:
(c) Dioptre

Question 19.
The image formed by simple microscope is
(a) Virtual and erect
(b) Inverted and virtual
(c) Real and erect
(d) Real and inverted
Answer:
(a) Virtual and erect

Question 20.
Light waves are
(a) Transverse wave
(b) Longitudinal wave
(c) Progressive wave
(d) None of these
Answer:
(a) Transverse wave

Question 21.
The bending of light from obstacle is called
(a) Dispersion
(b) Diffraction
(c) Refraction
(d) Interference
Answer:
(b) Diffraction

Question 22.
The momentum of photon which have 1 mega electron volt energy is
(a) 10^-22 kg m/s
(b) 10^-26 kg m/s
(d) 7 x 10^-24 kg m/s
(c) 5 x 10^-22 kg m/s
Answer:
(c) 5 x 10^-22 kg m/s

Question 23.
The energy of photon of wave length λ is
(a) he λ
\(\text { (b) } \frac{h c}{\lambda}\)
\(\text { (c) } \frac{h \lambda}{c}\)
\(\text { (d) } \frac{\lambda}{h c}\)
Answer:
\(\text { (b) } \frac{h c}{\lambda}\)

Question 24.
When a hydrogen atom is excited from its ground state to fourth orbit the maximum number of spectral line that can be emitted as
(a) 6
(b) 4
(c) 3
(d) 1
Answer:
(a) 6

Question 25.
The unit of Rydberg’s constant is
(a) m^-1
(b) m
(c) s^-1
(d) s
Answer:
(a) m^-1

Question 26.
Which is chargeless particle ?
(a) a-particle
(b) P-particle
(c) proton
(d) photon
Answer:
(d) photon

Question 27.
α-rays are
(a) Electromagnetic wave
(b) Negative charged particle
(c) Positive charged particle
(d) Chargeless particle
Answer:
(c) Positive charged particle

Question 28.
The mixing of impurity in semi conductor is called
(a) Doping
(b) Hybridization
(c) Sublimation
(d) None of these
Answer:
(a) Doping

Question 29.
The current carriers are in N-type semi condutor is
(a) proton
(b) hole
(c) a-particle
(d) electron
Answer:
(d) electron

Question 30.
The resistance of semi conductor after increasing temperature
(a) increases
(b) decreases
(c) remains constant
(d) None of these
Answer:
(b) decreases

Question 31.
p-n junction diodes are used as
(a) An amplifier
(b) Oscillator
(c) Modulator
(d) Rectifier
Answer:
(d) Rectifier

Question 32.
P-type and N-type semi conductor are
(a) Electrically neutral
(b) Electrically positive
(c) Electrically negative
(d) None of these
Answer:
(a) Electrically neutral

Question 33.
The maximum distance upto which T.V. signal can be received from Antenna of height h is
\((a) \sqrt{2 h} \mathrm{R}
(b) h \sqrt{2 R}\)
\(\text { (c) } \mathrm{R} \sqrt{2 h}\)
(d) None of these
Answer:
\((a) \sqrt{2 h} \mathrm{R}\)

Question 34.
The polarisation of ground wave is
(a) in any direction
(b) at angle 60°
(c) perpendicular
(d) parallel
Answer:
(c) perpendicular

Question 35.
The sun obtained radiant energy with
(a) Nuclear fission
(b) Nuclear disintegration
(c) Chemical reaction
(d) Nuclear fusion
Answer:
(d) Nuclear fusion

Non-Objective Type Questions
Short Answer Type Questions

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

Question 1.
Define dielectric constant and dielectric strength.
Answer:
Dielectric constant:
The ratio of strength of applied electric field to the strength of reduced value of electric field on placing the dielectric b/w the plates of capacitor is called dielectric constant of dielectric medium. It is.also known as relative permitivity and denoted by K the value nx K is always greater than 1.

Dielectric Strength :
It is defined as the maximum value of electric field that can be applied to the dielectric without its electric breakdown.

S.I. unit of dielectric strength is Vm^-1.

Question 2.
Establish the relation between electric field (E) and potential (V)
Answer:
\(\mathrm{E}=-\frac{d v}{d r}\) Here, Negative sign indicates that when distance increases potential decreases.

The term \(\frac{d v}{d r}\) is called potential gradient.

Question 3.
Write two uses of potentiometer.
Answer:

• The electro motive force (emf) of two cells are compared by potentiometer,
• The internal resistance of cell is determined by potentiometer.

Question 4.
What is Seeback effect ?
Answer:
The phenomenon of producing thermoelectric emf (or thermoelectric current in thermo couple) by keeping its two junctions at different temperature is called Seeback effect. The current produced in this way is called thermoelectric current and emf produced in this may be called thermoelectric emf.

Question 5.
Distinguish between electromagnet and permanent magnet.
Answer:
Electro-magnet:

• Magnetic strength can be change
• The material of electro-magnet has high retentivity.
• The material of electro-magnet has low coericivity
• It has permeability.

Permanent magnet :

• Magnetic strength is fixed,
• It has low retentivity.
• It has low coericivity
• It has permeability

Question 6.
What is Eddy currents ?
Answer:
When magnetic flux linked with metallic conductor changes, induced current are set up in the conductor in the form of closed loops. These current looks like ‘eddies’ or ‘whirl pools’ and likewise are known as eddy currents.

Thus, eddy currents are the currents induced in a conductor, when placed in changing magnetic field.

Question 7.
What is Transformer ? Define transformation ratio.
Answer:
Transformer:
It is a device which is well to convert low voltage at high current in high a.c. voltage at low current and vice-versa. It is based on the principle of mutual induction.

Transformation Ratio :
The ratio of number of turns of wire in secondary coil to the number of turns of wire in primary coil, is called transformation ratio.

\(\frac{N s}{N p}=K\) K is called Transformation Ratio

Question 8.
The radius of curvature of double convex lens are 10 cm and 15 cm. If focal length of limits is 12 cm, then find the refractive index of the material of the prism.
Answer:
Given R₁ = 10 cm, R₂ = – 15 cm, f = 12 cm

Question 9.
What is critical angle ? And what are the conditions for total internal reflection ?
Answer:
Critical Angle :
The angle in incidence corresponding to which angle of refraction becomes 90°, is called critical angle. It is denoted by ic

Conditions for total Internal Reflection :

• The light should travel from denser medium to rarer medium.
• The angle of incidence must be greater than critical angle for given pair of media..

Question 10.
Write two properties of X-rays.
Answer:

• They are not deflected by electric or magnetic field.
• They travel with the speed of light as electro¬magnetic wave.

Question 11.
State two properties of nuclear force.
Answer:

• It is only attractive force,
• It is strong fundamental force in value/nature.

Question 12.
What is the de-Broglie associated with an electron, accelerated through a potential difference of 100 volt.
Answer:

Question 13.
What is photo electric effect ? Write photo electric equation.
Answer:
The phenomenon of emission of electron from the metallic surface when suitable wave length of light is incident upon it, is called photoelectric effect. Photoelectric equation is
\(\frac{1}{2} m v^{2}=h v-h v_{0}\)

Question 14.
Write two characteristics of LASER rays.
Answer:

• It is highly directional with parallel beam.
• It is monochromatic and coherent.

Question 15.
Mention the advantages of LED.
Answer:

• Light emitting diodes are easily manufactured.
• LEDs have 10W cost.
• It works at 10W voltage as compared to in- condescend bulb.
• No warm up time is taken by them.
• They can emit monochromatic light as well as bright light.

Question 16.
What will be the result if a student connects Voltmeter in series and Ammeter in parallel in circuit by mistake ?
Answer:
By presence of Voltmeter in series with Resistance R in a circuit due to voltmeters high resistance, the current in the cirucuit I (= V/R) will decrease appreciably to I¹ (= V/R) and as their I¹ will further divide in Resistance R and ammeter, the currrent through ammeter I² will be eveiv lesser than I¹. Also the applied potential difference V will divide across resistance R and voltmeter, so the potential difference across voltmeter V₂ will be lesser than V. Since I₂ and V₂ both are lesser than I and V respectively, none, of the instrument will be damaged.

Question 17.
How do (a) the pole strength and (b) the magnetic moment of each part of bar magnet change, if is cut into two equal parts along its length.
Answer:

Initially, Magnetic moment M = m.2l

In this position length becomes half then
\(M^{1}=m \cdot \frac{2 l}{2}=\frac{M}{2}\)

Polar strength remains same but magnetic moment becomes half of its initial value.

Question 18.
Calculate induced emf in a moving conductor in an uniform magnetic field.
Answer:
Let length of conductor PQ – 1
As x = 0, magnetic flux Φ = 0.
When PQ moves a small distance from x to x + dx, then magnetic flux linked = BdA = Bldx

The magnetic field is from x = 0 to x = b, so final magnetic flux = ΣBldx = Bl Σdx
= Blb (increasing)

Mean magnetic flux from x = 0 to x = b is 1/2 Bib.

The magnetic flux from x = b to x = 2b is zero. Induced emf,
\(\varepsilon=-\frac{d \phi}{d t}=-\frac{d}{d t}(B l d x)=-B l \frac{d x}{d t}=-B l v\)

where \(v=\frac{d x}{d t}\) = velocity of arm PQ from x = 0 to x = b.
During return from x = lb to x = b the induced emf is zero; but now area is decreasing so magnetic flux is decreasing, and induced emf will be in opposite direction.

Long Answer Type Questions

Question 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.
Explain the principle on which Van de Graaff generator operates. Draw a labelled schematic sketch and write briefly its working.
Answer:
Construction :
It consists of a large hollow metallic sphere S mounted on two insulating columns A and B and an endless belt of rubber or silk is made to run on two pulleys P₁ and P₂ by the means of an electric motor. C₁ and C₂ are two sharp metallic spikes in the form of combs. The lower comb C₁ is connected to the positive terminal of a very high voltage source (HTS) (= 104 volts.) and the upper comb C₂ is connected to the inner surface of metallic sphere S.

Working:
When comb C₁ is given very high potential then it produces ions in its vicinity, due to action of sharp points. The positive ions, so produced, get sprayed on the belt due to repulsion between positive ions and comb C₁. These positive ions are carried upward by the moving belt. The pointed end of C₂ just touches the belt. The comb C₂ collects positive charge from the belt which immediately moves to the outer surface of sphere S. As the belt goes on revolving, it continues to take (+) charge upward which is collected by comb C₂ and transferred to outer surface of sphere S. Thus the outer surface of metallic sphere S gains positive charge continuously and its potential rises to a very high value.

When the potential of a metallic sphere gains very high value, the dielectric strength of surrounding air breaks down and its charge begins to leak, to the surrounding air. The maximum potential is reached when the rate of leakage of charge becomes equal to the rate of charge transferred to the sphere. Thus, the high voltages can he built up to breakdown field of the surrounding medium. To prevent leakage of charge from the sphere. the generator is completely enclosed in an earthed connected steel tank which is filled with air under high pressure.

Van de Graaff generator is used to accelerate stream of charged particles to very high velocities. Such a generator is installed at ¡IT Kanpur which accelerates charged particles upto 2 MeV energy.

Question 20.
(a) State the principle of working of a potentiometer.
(b) Draw a circuit diagram to compare the cmf of two primary cells. Write the formula used. How can the sensitivity of a potentiometer be increased?
Answer:
Principle of Potentrometer:
Principle: It is based on the principle that when constant current passes from unifòrm cross sectional area of wire thus potential drop across any portion f wire is directly proportional to length of that portion of wire.

V ∝ l

Comparison of emPs òf two cells:
First of all the ends of potentiometer are connected to a battery B1, key K and Rheostate Rh such that the positive terminal of battery 1 is connected to end A of the wire. This completes the primary circuit.

Now the positive terminals of the cells C₁ and C₂ whose emfs are to be compared are connected to A and the negative terminals to the jockey J through a two way key and a galvanometer (fig). This is the secondary circuit.

Method :
(i) By closing key K, a potential difference is established and rheostat is so adjusted that when jockey J is made to touch at ends A and B of wire, the deflection in galvanometer is on both sides. Suppose in this position the potential gradient is k.

(ii) Now plug is inserted between the terminals 1 and 3 so that cell C j is included in the secondary circuit and jockey J is slided on the wire at Pj (say) to obtain the null point. The distance of P, from A is measured. Suppose this length is l₁ i.e. AP₁ = l₁.

∴ The emf of cell C₁, ε₁ = kl₁ …………….. (i)

(iii) Now plug is taken off between the terminals 1 and 3 and inserted in between the terminals 2 and 3 to bring cells C₂ in the circuit. Jockey is slided on the wire and null deflection position P₂ is noted. Suppose distance of P₂ from A is I₂ i.e., AP-) = l₂
The emf of cell C₂, ε₂ = d₂ ………………(ii)
Dividing (i) by (ii), we get
\(\frac{\varepsilon_{1}}{\varepsilon_{2}}=\frac{l_{1}}{l_{2}}\) ………….(iii)

Thus emfs of cells may be compared. Out of these cells if one is standard cell, then the emf of other cell may be calculated.

Question 21.
State KirchofTs law. Write its one application based on this law (Wheatstone bridge).
Answer:
Kirchoff’s law : First law :
In the network of conductor the algebraic sum of current meeting at a point is always zero. It also causes junction rule.

Second law:
It states that in any closed part of an electrical circuit, the algebraic sum of the emf is equal to the algebraic sum of the products of the resistance and current flowing through them. It is also called loop rule. This law is based on the law of conservation of energy.

Wheatstone bridge :
It is one of the accurate arrangements for measuring an unknown resistance. It is based on the principle of Kirchoff s law.

Four resistance P, Q, R and S are connected to form a quadrilateral of galvanometer and a tapping key kl (called galvanometer) are connected between points B and D as shown in the figure.

Applying Kirchoff s second law, for closed part ABDA in the circuit I₁ P + I_g. g – (I – I₁) S = 0

where g is the resistance of the galvanometer
In the balanced state I_g = 0

Applying Kirchoff s law in closed part BDCB
I_g. g + (I – I₁ + I_g) R – (I₁ – I_g) Q = 0
O + (I – I₁) R – I₁ Q = 0
(I – I₁) R = I, Q
\(\frac{Q}{R}=\frac{I-I_{1}}{I_{1}}\) ………………… (ii)

From equation (i) and (ii)
\(\frac{P}{S}=\frac{Q}{R}\left[S=\frac{P}{Q} \cdot R\right]\)

Thus unknown resistance can be calculated.

Question 22.
Draw a ray diagram for formation of image of a point object by a thin double convex lens having radii of curvature Rj and R2. Hence, derive lens maker’s formula for a double convex lens. State the assumptions made and sign convention used.

Or, Using the relation for refraction at a single spherical refracting surface, derive the lens makers formula.
Answer:
Lens Maker’s Formula :
Suppose L is a thin lens. The refractive index of the material of lens is n₂ and it is placed in a medium of refractive index n₁. The optical centre of lens is G and X. X is principal axis. The radii of curvature of the surfaces of the lens are R₁ and R₂ and their poles are P₁ and P₂. The thickness of lens is t, which is very small. O is a point object on the principal axis of the lens. The distance of O from pole P₁ is u. The first refracting surface forms the image of O at I’ at a distance v’ from P₁.

From the refraction formula at spherical surface,
\(\frac{n_{2}}{v^{\prime}}-\frac{n_{1}}{u}=\frac{n_{2}-n_{1}}{\mathrm{R}_{1}}\) ………………………. (i)

The image I’ acts as a virtual object for second surface and after refraction at second surface, the final image is formed at I. The distance of I from pole P₂ of second surface is v. The distance of virtual object (T) from pole P₂ is (v’ -t).

For refraction at second surface, the ray is going from second medium (refractive index n₁) to first medium (refractive index n₂), therefore from refraction formula at spherical surface.

\(\frac{n_{1}}{v}-\frac{n_{2}}{\left(v^{\prime}-t\right)}=\frac{n_{1}-n_{2}}{\mathrm{R}_{2}}\) ……………………. (ii)

For a thin lens t is negligible as compared to v’, therefore from (ii)

where \(\mathrm{l} n_{2}=\frac{n_{2}}{n_{1}}\) is refractive index of second medium (i.e. medium of lens) with respect to first medium.

If the object O is at infinity, the image will be formed at second focus i.e.,

if u = α, v = f₂ = f, Therefore from equation (iv)

This is the formula of refraction for a thin lens. This formula is called Lens-Maker’s formula.

If first medium is air and refractive index of material of lens be n, then ₁n₂ = n, therefore equation (v) may be written as

Question 23.
(a) With the help of a diagram, explain the principles and working of a moving coil galvanometer.
(b) What is importance of a radial magnetic field and how is it produced?
Answer:
(a) Moving coil galvanometer : A galvanometer is used to detect current in a circuit.

Construction :
It consists of a rectangular coil around on a non-conducting metallic frame and is suspended by phosphor bronze strip between the pole pieces (N and S) of a strong permanent magnet.

A soft iron core in cylindrical form is placed between the coil.

One end of coil is attached to suspension wire which also serves as one terminal (T₁) of galvanometer. The other end of coil is connected to a loosely coiled strip which serves as the other terminal (T₂). The other end of the suspension is attached to a torsion head which can be rotated to set the coil in zero position. A mirror (M) is fixed on the phosphor bronze strip by means of which the deflection of the coil is measured by the lamp and scale arrangement. The levelling screws are also provided at the base of the instrument.

The pole pieces of the permanent magnet are cylindrical so that the magnetic field is radial at any position of the coil.

Principle and working :
When current (I) is passed in the coil, torque t acts on the coil, given by τ = NIABsinθ where θ is the angle between the normal to plane of coil and the magnetic field of strength B, N is the number of turns in a coil.

When the magnetic field is radial, as in the case of cylindrical pole pieces and soft iron core, then in every position of coil the plane of the coil, is parallel to the magnetic field lines, so that 0 = 90° and sin 90° = Deflecting torque, τ = NIAB

If C is the torsional rigidity of the wire and 0 is the twist of suspension strip, then restoring torque = Cθ

For equilibrium, deflecting torque = restoring torque
i.e., NIAB = Cθ
∴ \( \quad \theta=\frac{N A B}{C} I\) ………………. (i)
i.e, θ ∝ I

deflection of coil is directly proportional to current flowing in the coil and hence we can construct a linear scale.

(b) (i) Importance (or function) of uniform radial magnetic field : Torque as current carrying coil in a magnetic field is θ = NIAB sin θ
In radial magnetic field sin θ = 1, so torque is τ = NIAB.

This makes the deflection (θ) proportional to current. In other words, the radial magnetic field makes the scale linear.

(ii) Function of soft iron core : To produce radial magnetic field pole pieces of permanent magnet are made cylindrical and a soft iron core is placed between them. The soft iron core helps in making the field radial and reduce energy losses produced due to eddy currents.

Question 24.
Using the postulates of Bohr’s model of hydrogen atom, obtain an expression for the frequency of radiation emitted when atoms make a transition from the higher energy state with quantum number n_i. to the lower energy state with quantum number n_f (n_f < n_i)
Answer:
Suppose m be the mass of an electron and e its speed in nth orbit of radius r. The centripetal force for revolution is produced by electrostatic attraction between electron and nucleus.

Again from Bohr’s postulate for quantization of angular momentum

If n_i and n_f are the quantum numbers of initial and final states and E_i & E_f are energies of electron in H-atom in initial and final state, we have
\(\mathrm{E}_{i}=\frac{-\mathrm{R} h c}{n_{i}^{2}} \text { and } \mathrm{E}_{f}=\frac{-\mathrm{R} h c}{n_{f}^{2}}\)

If v is the frequency of emitted radiation, we get \(v=\frac{\mathrm{E}_{i}-\mathrm{E}}{h}\)
\(v=\frac{-\mathrm{R} c}{n_{i}^{2}}-\left(\frac{-R c}{n_{f}^{2}}\right) ; \quad v=\mathrm{R} c\left[\frac{1}{n_{f}}-\frac{1}{n_{i}^{2}}\right]\)

Bihar Board 12th Biology Model Papers

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

Time : 3 Hours 15 Min
Total 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 indicate full marks.
3. While answering the questions, the candidate should adhere to the word limit as for 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 result will be treated as invalid.
7. In Section – B, there are Non-objective type questions. There are 18 Short answer type questions, out of which any 10 questions are to be answered. Each question carries 2 marks. Apart from this, there are 6 long answer type questions, out of which any 3 of them are to be answered. Each question carries 5 marks
8. Use of any electronic device is prohibited.

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.
Fusion of male gametes with secondary nuclei is called
(a) Syngamy
(b) Triple fusion
(c) Geitenogamy
(d) Cleistogamy
Answer:
(b) Triple fusion

Question 2.
A large cluster of ribosome is called
(a) Megasome
(b) Microsome
(c) Polyribosome
(d) All of the above
Answer:
(c) Polyribosome

Question 3.
Which of the following is a biofertilizer?
(a) Cynobacteria
(b) Mycorhiza
(c) Symbiotic bacteria
(d) All of the above
Answer:
(d) All of the above

Question 4.
Middle piece of a mammalian sperm contains
(a) Nucleus
(b) Centriole
(c) Mitochondria
(d) None
Answer:
(c) Mitochondria

Question 5.
Acrosome is present in
(a) Sperm
(b) Ova
(c) Ovary
(d) All of the above
Answer:
(a) Sperm

Question 6.
Anemophily can be best seen in
(a) Sunflower
(b) Maize
(c) Pig
(d) Yucca
Answer:
(b) Maize

Question 7.
Citric acid is produced by
(a) Acetobacter Aceti
(b) Yeast
(c) Aspergillus niger
(d) Streptococcus
Answer:
(c) Aspergillus niger

Question 8.
Which of the following cells present in mammalian testes help to nourish sperms?
(a) Leydig cell
(b) Male germ cells
(c) Autosomes
(d) Sertoli cells
Answer:
(d) Sertoli cells

Question 9.
Which one of the following is false fruit?
(a) Mango
(b) Banana
(c) Apple
(d) All of the above
Answer:
(c) Apple

Question 10.
Binary fission occurs in
(a) Lotus
(b) Amoeba
(c) Water hyacinth
(d) All of the above
Answer:
(b) Amoeba

Question 11.
The concept of Lac operon was given by
(a) Beadle & Tatum
(b) Watson and Crick
(c) Jacobe and Monad
(d) None of the above
Answer:
(c) Jacobe and Monad

Question 12.
The term ecosystem was coined by
(a) Lamarck
(b) Darwin
(c) A.G. Tansley
(d) All of the above
Answer:
(c) A.G. Tansley

Question 13.
Minamata disease is due to pollutant
(a) H₂
(b) SO₂
(c) Mercury
(d) All of the above
Answer:
(b) SO₂

Question 14.
Which one of the following is the high-milk yielding variety of cow?
(a) Holstein
(b) Pashmina
(c) Dorset
(d) All of the above
Answer:
(a) Holstein

Question 15.
In plant meiosis occurs in
(a) Pollen grain
(b) Anther
(c) Root tip
(d) None
Answer:
(b) Anther

Question 16.
Example of corm is
(a) Onion
(b) Ginger
(c) Colocasia
(d) None of the above
Answer:
(c) Colocasia

Question 17.
Which of the following is chain initiation of codon?
(a) AUG
(b) UAG
(c) UUA
(d) CCC
Answer:
(a) AUG

Question 18.
Widal Test is done to confirm
(a) Typhoid
(b) Malaria
(c) Filaria
(d) All of the above
Answer:
(a) Typhoid

Question 19.
Which microbe is used in manufacturing of bread?
(a) Anabena
(b) Algae
(c) Baker’s Yeast
(d) All of the above
Answer:
(c) Baker’s Yeast

Question 20.
Human genome project was discovered by
(a) Watson and Crick
(b) Beadle and Tatum
(c) Francis Collins and Roderick
(d) None
Answer:
(c) Francis Collins and Roderick

Question 21.
Embryo sac is created by which of the following?
(a) Megaspore
(b) Microspore
(c) Both
(d) None of the above
Answer:
(a) Megaspore

Question 22.
Down’s Syndrome in child is due to
(a) Gene mutation
(b) Monosomy
(c) Trisomy
(d) All of the above
Answer:
(c) Trisomy

Question 23.
On which insect group Bt-toxin is effective?
(a) Dipteron
(b) Lepidopteron
(c) Choleopteron
(d) All of the above
Answer:
(d) All of the above

Question 24.
Miller prepared in laboratory
(a) Amino acid
(b) Ammonia
(c) Hydrogen
(d) All of the above
Answer:
(a) Amino acid

Question 25.
Dinosaurs found in the era of
(a) Permian
(b) Modem
(c) Carboniferrous
(d) Jurassic
Answer:
(d) Jurassic

Question 26.
PCR is used in Amplification of
(a) Protein
(b) Enzyme
(c) Segment of DNA
(d) All of the above
Answer:
(c) Segment of DNA

Question 27.
Genetically engineered human insulin is made by
(a) Plant
(b) Yeast
(c) Bacterium
(d) All of the above
Answer:
(c) Bacterium

Question 28.
What is Mala D?
(a) Contraceptive
(b) Vitamins
(c) Medicine for fever
(d) None of the above
Answer:
(a) Contraceptive

Question 29.
Which among is cancer?
(a) Leukemia
(b) Lymphoma
(c) Liposa
(d) All of the above
Answer:
(d) All of the above

Question 30.
Second trophic level in lake is
(a) Phytoplankton
(b) Zooplankton
(c) Both
(d) None of the above
Answer:
(b) Zooplankton

Question 31.
Which of the following is known as green house gas?
(a) Methane
(b) CFC
(c) C02
(d) All of the above
Answer:
(d) All of the above

Question 32.
The first human like being the homonid was called
(a) Homo sapiens
(b) Homo erectus
(c) Homo habilis
(d) All of the above
Answer:
(c) Homo habilis

Question 33.
AIDS is STD which is transmitted through
(a) Sexual contact
(b) Blood transmission
(c) Contaminated syringe
(d) All of the above
Answer:
(d) All of the above

Question 34.
The virus which cause cancer is known as
(a) TMV
(b) Oncogenic virus
(c) Bacteriophage
(d) All of the above
Answer:
(b) Oncogenic virus

Question 35.
Ozone layer is found in
(a) Troposhpere
(b) Mesosphere
(c) Stratosphere
(d) All of the above
Answer:
(c) Stratosphere

Non-Objective Type Questions

Short Answer Type Questions

In this section, there are 18 short answer type question (each carryies 2 marks) out of which answers any ten (10) questions. (10 x 2 = 20)

Question 1.
Explain contact inhibition?
Answer:
Uncontrolled cell division and proliferation growth & multiplication is sign of cancer cells & cancer disease. Cancerous cells are called malignant neoplasm, which develops on neighboring cells (by taking nutritive elements from them) grow and multiply. At last these cancerous cells kills the neighboring cells. These cancerous cells when come in contact with normal cell, they inhibit the growth and dynamic of these cells. This property of cancer cells are called contact inhibition.

Question 2.
Write the effects of Acid Rain.
Answer:
Effects of Acid Rain:

• Acid rain damages a number of heritage monuments due to deposition of acids, eg. Statue of Liberty, Taj Mahal etc.
• Acid rain kills the useful soil microbial community thus disturbing terrestrial ecosystems.
• In the aquatic ecosystem acid rain below 4 pH causes death of planktons, molluscs and fishes, therefore it disturbs the food chain.

Question 3.
How does killer T-cells act?
Answer:
T-cells attack directly and destroy antigens. In the process, these cells move to the site of invasion and produce chemicals that attract phagocytes and stimulate them so that they can feed more vigorously on antigens. They also produce substances that attract other T-cells.

Question 4.
Describe the symptoms & preventions of malaria disease.
Answer:
Symptoms :

1. Fever with coldness, chill, headache & muscular pain.
2. Decrease in RBC count.
3. Spleen increases in size
4. Fever comes alternatively at 48 hours.

Preventions :
(a) Through Destroying Mosquitoes – Malaria is spread by the bite of female anophelese mosquitoes, therefore, destroying them, we can prevent the disease. For this spraying of DDT & Kerosine and their biological control through Gambusia fish is very useful.

(b) Prevention through infection – Every person should use mosquito net. If necessary mosquito cream available in market should be used for protection from mosquito bite. Medicines like Quinine and Paludrin may be used for treatment of malaria.

Question 5.
Write short notes on tRNA.
Answer:
Transfer RNA : A transfer RNA (tRNA) molecule has the form of a cloves leaf that results from self
folding and base pairing, creating paired stems and unpaired loops. It has four regions (a) Carrier end (b) Recognition end (c) Enzyme site (d) Ribosome site. It forms about 10¬15% of the total RNA.

Question 6.
Write any four bacterial diseases and its pathogens.
Answer:
Cholera – Vibrio cliolerae
Tuberculosis – Mycobacterium tuberculosis
Titanus – Clostridium tetani
Pneumonia – Streptococcus pneumoni

Question 7.
Name the enyzmes which are employed in genetic engineering.
Answer:
Following enzymes are employed in genetic engineering:
(a) Lysing enzymes – Lysozyme
(b) Cleaving enzymes
(i) Exonuclease
(ii) Endonuclease
(iii) Restriction endonuclease
(c) Synthesizing enzymes
(i) DNA polymerase
(ii) Reverse transcriptase
(d) Joining enzymes
(e) Alkaline phosphotase

Question 8.
Give differences between Nucleoside and Nucleotide.
Answer:

	Nucleoside	Nucleotide
1.	A nucleoside consists of a nitrogenous base covalently attached to sugar but without the phosphate group.	1. A nucleotide consists of nitrogenous base, asugar and one to three phosphate group.
2.	Nature is Alkaline.	2. Nature is Acidic.
3.	They are components of nucleotides	3. They are components  of energy carriers and co-enzymes.

Question 9.
Mention the names of Five diseases caused by Helminthes. Give symptoms & control of one disease.
Answer:
Name of disease:

• Ascariasis Ascaris
• Filariasis

Causative agent:

• lumbricoides
• Wuchereria bancrafti

Syptoms of Ascariasis-1. Loss of Apetite 2. Pain in stomach 3. Increased number of worms in intestine may block the cavity which may create problem.
Control-

1. After 12 hrs. of fasting one dose of Hexil resorsinol is given due to which worms come outside with stool.
2. Tetrachloroethylene and oil of Chenopodium in mixture is very effective.
3. Hetrazon & Piprazinhydrate drugs are helpful.

Question 10.
What is significance of Parthenogenesis?
Answer:
Significance of Parthenogenesis :

1. It helps in determining the sex of an animal as in honey bee.
2. It overcomes the wastage of energy spent upon the process of mating and fertilization by an animal.
3. It rapidly increases the number of animals in a population.

Question 11.
What is ’In situ’ conservation? What is its benefit?
Answer:
In situ conservation is the process of protecting the endangered species of plant or animal in the natural habitat either by protecting or cleaning up the habitat itself or by defending the species from predators. It helps in recovering the population in the surroundings where they have developed their distinctive features.

Question 12.
Expand MTP. Why it is so done?
Answer:
MTP stands for Medical Termination of Pregnancy. It is the intentional termination of pregnancy before full term. It is done to get rid of unwanted pregnancy due to rapes, or unprotected intercourse or failure of the contraceptive used during coitus. It has a significance role in decreasing the population though it is not performed for that purpose.

Question 13.
Describe the functions of antibody.
Answer:

1. Antibody neutralizes the toxins produced by bacteria.
2. By combining with antigen, antibody makes a macromolecular insoluble complete substance which inactivates the vital function of antigen.
3. By oponization antibody get the bacteria in such a way that phagocytes identify them easily.

Question 14.
Write on control of sound pollution.
Answer:
Control of Noise Pollution :

• There could be developed gadgets to control noise at source of noise.
• Industrial units should be established away from high density populated areas.
• Loudspeakers should be banned.
• Sound absorbers should be used.
• For control of sound pollution the laws should be enforced effectively.

Question 15.
Write short notes on Lamarckism.
Answer:
French naturalist Lamarck has said that ’evolution of life forms had been driven by use and disuse of organs. He gave the example of Giraffes who in an attempt to forage leaves on tall trees had to adapt by elongation of their necks. As they passed on the acquired character of elongated neck to succeeding generations. Giraffe slowly over the years, came to acquire long necks.

Question 16.
What do you mean by term-mycorrhiza?
Answer:
It is the symbiotic association of fungal hyphae roots of higher plants. The fungal hyphae absorbs phosphorus from the soil and passes it to the plant. The plant also gets other benefits such as resistance to root-borne pathogens, tolerane to salinity and drought and increase in growth and development. In turn, the fungal hyphae get the nutrition from the plants.

Question 17.
What is test cross? Give its utility.
Answer:
Test cross : It is a cross between Fj hybrid and the recessive parent. The hybrid of F( generation, that is produced by inter-crossing two different parents may be similar phenotypically but genotypically, it may be heterozygous. To confirm the purity of Ft hybrid whether it is homozygous or heterozygous a test cross is done.

1. If the test cross yields offsprings of 50% dominant and 50% recessive character, then the F[ hybrid is heterozygous. It shows (1:1) test ratio for monohybrid cross and (1 : 1 : 1 : 1) for dihybrid cross.
2. If the test cross yields all the dominant character, then the Fj hybrid is homozygous.

Question 18.
State the relationship between linkage and crossing over.
Answer:
The linked genes do not always remain linked but are occasionally departed from other members of their linkage groups by crossing over. But the frequency of crossing over depends upon the distances between the various genes located on the same chromosome.

If the distances between the genes is more, then chances of crossing over and recombination are more. If the genes are closely placed on the same chromosome and the frequency of their separation is less than 50%, then there are less chances of departure of crossing over. In this case, the genes will remain linked and the progeny will be parental type.

Long Answer Type Questions

There are 6 long answers type question (each carrying 05 marks) out of which answers any three questions. (5 x 3 = 15)

Question 19.
What do you understand by Polyembryony? Describe it in detail. Discuss the Mendel’s Law of Inheritance.
Answer:
Occurrence of more than one embryo in a seed is referred to as polyembryony. Polyebryony was discovered by Leeuwenhoek in 1719. It is mostly found in gymnosperms and less found in angiosperms (eg. Mango, lemon etc.). It is of two types-true polyembryony and false polyembryony.

Causes of polyembryony are as follows :

1. When more than one embryo sac in ovule;
2. When more than one egg cell in embryo sac;
3. When after fertilization, egg is separated in many small parts and every part forms a embryo;
4. When any cell of embryo sac forms embryo;
5. When embryo is formed by outer cells of embryo sac.

Importance of polyembryony are:
(a) It is very important for horticulture scientists.
(b) By this same types of plants may be formed.
(c) Characters of mother plants are present in daughter plants.

There are four principles of Mendel’s law of inheritance which are based on Monohybrid and Polyhybrid crosses.

(a) Principles of paired factors: The determination of characters in an organism (diploid) is marked by atleast two factors. Such factors are present on two chromosomes of the same locus.

(b) Law of dominance: In any heterozygous organism the representation of characters takes place by two contrasting characters in which one is dominant while the other is recessive.

(c) Law of Segregation: Two factors of any character who remain together can not mix with one another. However they get separated during gametogenesis.

(d) Law of Independent Assortment: According to this principle, two factors of each character get separated independently during gamete formation and again become re-arranged in off springs.

Question 20.
Write about three ecological pyramids with suitable examples.
Answer:
Ecological Pyramids. represents the humerical relationship between different trophic levels of a food chain. These are of three types:
(i) Pyramid of Number: It indicates that the producers which form the base of the Pyramid are ingested large numbers by a comparatively small number of primary consumers. These eaten by a small number of primary cornivoes, which is also ingested by still amall number of tertiary consumers or secondary carnivores.

(ii) Pyramid of biomass: The biomass i.e. the living weigst of the organismas of the food chin present at any time in an ecosystem forms the pyramid of biomass. The pyramid of biomass indicates the decrease in biomass ar each troth ic level from base to apex.

(iii) Pyramid energy: It indicates the total energy at each trophic level of this food chain. It also exhibits that at each trophic level loss of energy and material takes place as the process of assimilation and growth are not 100% efficient.

Question 21.
What is Gene therapy ? Describe it by using the example of adenosine diaminase (ADA) deficiency.
Answer:
Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo. Here genes are inserted into a person’s cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene.

The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine diaminase (ADA) deficiency. This enzyme is crucial for the immunical system to function. This disorder is caused due to the deletion of the gene for adnesinal diaminase. In some children ADA deficiency can be cured by bone marrow transplantation; in others it can be treated by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But the

problem with both of these approaches that they are not completely curative. As a first step towards gene therapy, lymphocyte from the blood of the patient are grown in a culture outside the body. A functions ADA cDNA (using a retroviral vector) is then introduced into these lymphocytes which are subsequently returned to the patient. However, as these cells are no immortal the patient requires periodic infusion of such genetically engineered lymphocytes. However, if the gene isolate from marrow cells producing ADA introduced into cells at early embryonic stages, it could be a permanent cure.

Question 22.
What is Darwinism/Theory of Natural Selection?
Answer:
Darwinism is the theory of Natural Selection given by Charles Darwin. He supported evolution by following principles:

1. Over production: Every organisms possess enormous fertility. They multiply in geometric ratio. But all of them do not survive.
2. Limited food and space: Despite of rapid multiplication of all types of species, food and space resources remain limited, they are not liable to increase.
3. Struggle for existence: Organism will have struggle for their existence. It may be intraspecific, Interspecific and environmental.
4. Survival of the fittest: The organisms which are provided with favourable variations would survive because they are the fittest to face their surrounding, whole the unfits are destroyed.
5. Inheritance of useful variation: Such useful variations are transmitted to the next generation while non useful variations are eliminated.
6. Formation of new species : Such useful variations appear more prominantly in succeeding generations. And finally formation of new species takes place.

Question 23.
What do you understand by crossing over ? Decribe the mechanism of crossing over with suitable diagram.
Answer:
Crossing over is a recombination of genes due to exchange of genetic material between two homologous chromosomes. It is the mutual exchange of sigments of genetic material between nonsister chromatids of two homologers chromosomes. So as to produce recombinations or new combinations of genes.
The nonsister chromatids in which exchange of segments has occured are called recombinants or cross overs while the other chromatids in which crossing over has not taken place are known as parental chromatids or non-cross-overs.

Mechanism of crossing over: Chromosomes get replicated in S-phase of interphase. Therefore, leptotene chromosomes are double stranded though the two strands are not visible due to presence of nucleoprotein complex in between the chromatids.

1. First of all homologous chromosomes pair.
2. Each member of pair devide into two chromatids. Thus each monovalent chromosome becomes bivalent.
3. If crossing over takes place then one chromosome twist-around the corresponding chromatid of the other chromosome.
4. At this point break occurs and broken par of one chromatid join the other broken part of other corresponding chromatid resulting in exchange of chromatid parts containing the genes.
5. The point at which crossing over takes place is called chiasmata.

Now each centromere of the homologous chromosome starts to separate from each other and the point of crossing over shifts towards the head of the chromosome. This movement of chiasmata is called criminalization. At the end of this the chromatids get separated.

Question 24.
Give an account of Pond Ecosystem.
Answer:
Pond Ecosystem: A small freshwater pond is a classic example of an ecosystem (aquatic). The follow¬ing two components are found in this ecosystem

(i) Abiotic components – The gases like CO₂ – O₂and other gases and inorganic substances are dissolved in pond water. Some abiotic components are found on the bottom of the pond. lit presence of sunlight, the green aquatic plants and algae manufacture the food material by photosynthesis with the help of CO₂ and water which is essential for different organisms. After the death of these plants and animals, the complex matter decomposes and goes into water again as abiotic component and thus ecosystem continues forever.

(a) Producers – All the green plants found in the pond e.g. Hydrilla, Marsilia, Ranunculus etc. and different types of Algae, Spirogyra, Volvox, Nostoc are examples of producers. All these producers prepare food by photosynthesis.

(b) Consumers – These can be divided into the following categories:
(iv) Primary Consuniers – Various types of small insects and their larvae, herbivores and fishes are primary consumers.
(v) Secondary consumers-These consumers are primary carnivores which eat the herbivores, e.g. frog, water snakes, bettles & some fishes etc.
(vi) Tertiary consumers-Carnivores fishes are found in the pond water which feed on the consumers of second-order small fishes.

(c) Decomposers – Various types of microorganisms eg. bacteria, fungi etc. are also present in the pond water which are called decomposers. They attack on dead bodies of producers and consumers and convert complex organic compounds into simple inorganic compounds.

Bihar Board 12th Business Studies Model Papers

Bihar Board 12th Business Studies Model Question Paper 4 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 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 questiion carries 1 (one) mark. [50 x 1 = 50]

Question 1.
Primary element of success of management is _________
(a) Satisfied employee
(b) Large capital
(c) Big market
(d) Maximum production.
Answer:
(b) Large capital

Question 2.
The propounder of administrative management was _________
(a) Fayol
(b) Taylor
(c) Terry
(d) None of them.
Answer:
(a) Fayol

Question 3.
The father of scientific management was _________
(a) Gilbreth
(b) F.W. Taylor
(c) Robertson
(d) Charles Babbage.
Answer:
(b) F.W. Taylor

Question 4.
Main component (s) of New Economic Policy is/ are _________
(a) Liberalisation
(b) Globalisation
(c) Privatisation
(d) All of these.
Answer:
(d) All of these.

Question 5.
Co-ordination is
(a) voluntary
(b) necessary
(c) unnecessary
(d) wastage of time.
Answer:
(b) necessary

Question 6.
“A plan is a trap to capture the future.” This statement is of _________
(a) Newman
(b) Hurley
(c) Allen
(d) Terry
Answer:
(c) Allen

Question 7.
A good plan is
(a) Rigid
(b) Expensive
(c) Flexible
(d) Time consuming
Answer:
(c) Flexible

Question 8.
Which of the following depends on the sweet will of employees ?
(a) Formal organisation
(b) Informal oganisation
(c) Functional organisation
(d) Divisional organisation
Answer:
(b) Informal oganisation

Question 9.
Authority cannot be delegated of _________
(a) Routine work
(b) Secret work
(c) Ordinary work
(d) Easy work
Answer:
(c) Ordinary work

Question 10.
Responsibility is of _________
(a) Subordinates
(b) Officer
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 11.
Money spent on staffing is _________
(a) necessary
(b) wastage
(c) investment
(d) none of these
Answer:
(c) investment

Question 12.
The manager is _________
(a) Boss
(b) Owner
(c) Leader
(d) None of these
Answer:
(c) Leader

Question 13.
Controlling is the aspect of management.
(a) theoretical
(b) practical
(c) mental
(d) physical
Answer:
(b) practical

Question 14.
Control is the function of the management.
(a) first
(b) last
(c) third
(d) second
Answer:
(b) last

Question 15.
Fixed capital is needed for period.
(a) short
(b) long
(c) short & long both
(d) none
Answer:
(b) long

Question 16.
The future of Stock Exchange in India is
(a) bright
(b) in dark
(c) ordinary
(d) no future
Answer:
(a) bright

Question 17.
Money market deals in _________
(a) short-term funds
(b) medium-term funds
(c) long-term funds
(d) none of these
Answer:
(a) short-term funds

Question 18.
For Stock Exchange services of SEBI are _________
(a) voluntary
(b) necessary
(c) unnecessary
(d) compulsory
Answer:
(d) compulsory

Question 19.
Which one is not the consumer product amongst the following ?
(a) Raw materials
(b) Refrigerator
(c) Old statues
(d) Shoes
Answer:
(c) Old statues

Question 20.
Costliest means of advertising is _________
(a) Advertising
(b) Personal selling
(c) Sales promotion
(d) Public relation
Answer:
(b) Personal selling

Question 21.
Consumer rights under Consumer Protection Act are _________
(a) 6
(b) 7
(c) 8
(d) 9
Answer:
(a) 6

Question 22.
When was SEBI established ?
(a) 1978
(b) 1988
(c) 1989
(d) 1998
Answer:
(b) 1988

Question 23.
The disputes that come under Consumer Protection Act are _________
(a) disputes as to sale of shares by a company
(b) disputes of penal nature
(c) disputes as to sale of defective goods by the seller
(d) service disputes
Answer:
(c) disputes as to sale of defective goods by the seller

Question 24.
Which of the following is not a vcharacteristic of entrepreneurship ?
(a) Risk
(b) Innovation
(c) Creative activity
(d) Managerial training
Answer:
(d) Managerial training

Question 25.
In any organisastion motivation is _________
(a) essential
(b) unnecessary
(c) burden
(d) wastage of time and money
Answer:
(a) essential

Question 26.
Source of trade credit is _________
(a) long-term finance
(b) medium-term finance
(c) sort-term finance
(d) none of these
Answer:
(c) sort-term finance

Question 27.
Comprehensive plan for accomplishing an organisation’s objectives is known as _________
(a) Policy
(b) Programme
(c) Objective
(d) strategy
Answer:
(d) strategy

Question 28.
Barrier in effective communication is _________
(a) language
(b) distance
(c) individual differences
(d) all of these
Answer:
(a) language

Question 29.
Supervisor is the link between _________
(a) top & middle management
(b) workers & middle management
(c) workers & lower management
(d) workers & directors
Answer:
(c) workers & lower management

Question 30.
Main function of financial management is _________
(a) Procurement of funds
(b) Utilisation of funds
(c) Allocation of funds
(d) None of these
Answer:
(a) Procurement of funds

Question 31.
Liquidity is created by _________
(a) Organised market
(b) Unorganised market
(c) Primary market
(d) Secondary market
Answer:
(a) Organised market

Question 32.
Stock Exchange protects the interest of _________
(a) Investor
(b) Company
(c) Government
(d) None of these
Answer:
(a) Investor

Question 33.
The birth place of concept of marketing management is _________
(a) England
(b) America
(c) France
(d) Japan
Answer:
(b) America

Question 34.
National Commission can settle consumer disputes
(a) up to Rs. 5 lakh
(b) up to Rs. 10 lakh
(c) up to Rs. 20 lakh
(d) above Rs. 1 crore.
Answer:
(c) up to Rs. 20 lakh

Question 35.
Entrepreneurial development programme provides _________
(a) unemployment
(b) employment
(c) dishonesty
(d) corruption
Answer:
(c) dishonesty

Question 36.
Management is _________
(a) Art
(b) Science
(c) Both Art and Science
(d) none of these
Answer:
(c) Both Art and Science

Question 37.
The maximum duration of commercial paper is _________
(a) 3 months
(b) 6 months
(c) 12 months
(d) 24 months
Answer:
(c) 12 months

Question 38.
Entrepreneurial Development Institute of India is situated in _________
(a) Ahmedabad
(b) Mumbai
(c) New Delhi
(d) Chennai
Answer:
(a) Ahmedabad

Question 39.
The essence of management is _________
(a) Co-ordination
(b) Organisation
(c) Staffing
(d) Control
Answer:
(a) Co-ordination

Question 40.
The organisation which spreads rumours is called _________
(a) formal
(b) informal
(c) centralised
(d) decentralised
Answer:
(b) informal

Question 41.
Commercial bill is written _________
(a) by purchaser
(b) by seller
(c) by bank
(d) by the government
Answer:
(c) by bank

Question 42.
Main elements of direction are _________
(a) 2
(b) 3
(c) 4
(d) 6
Answer:
(c) 4

Question 43.
Delegation of can be done.
(a) Authority
(b) Responsibility
(c) Accountability
(d) None of these
Answer:
(a) Authority

Question 44.
Which of the following statements is inconsistent ?
(a) Management is purposeful
(b) It is an instinct process
(c) Management is universal
(d) Management is not separate from ownership
Answer:
(c) Management is universal

Question 45.
Component (s) of new economic policy is /are _________
(a) Liberalisation
(b) Globalisation
(c) Privatisation
(d) All of these
Answer:
(d) All of these

Question 46.
depends on the wall of the employees.
(a) Formal organisation
(b) Informal organisation
(c) Functional organisation
(d) Divisional organisation
Answer:
(d) Divisional organisation

Question 47.
Method(s) of training is /are _________
(a) Conference
(b) Lectures
(c) prenticeship
(d) All of these
Answer:
(c) prenticeship

Question 48.
Motivational means should be determined on the basis of _________
(a) Group
(b) Individual
(c) Job
(d) All of these
Answer:
(d) All of these

Question 49.
In a business enterprise controlling is required _________
(a) at the time of setting up of business
(b) continuously
(c) at the time of operation of business
(d) at the end of the year
Answer:
(b) continuously

Question 50.
Main function(s) of financial management is/are _________
(a) Financial planning
(b) Procurement of funds
(c) Allocation of net profits
(d) All of these
Answer:
(d) All of these

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.
Controlling is forward looking. Explain.
Answer:
Controlling is looking forward because of remedial action is the essence of controlling. This will also include action to modify and improve upon the existing plans to prevent reference of the deviation noticed by the manager. Controlling helps in adoption of new plans and revision of existing plans on the basis of actual performance against standards.

Question 2.
Give the meaning of the term ‘deviation’ as used in the control function of management.
Answer:
Planning is provasive planning is required all levels of management as well as departments of the organisaiton. It is not exclusive function of top management nor of any particular departments.

Question 3.
What do you mean by capital structure ?
Answer:
Capital structure refers to the composition or make up or long-term sources of funds as : equity shares preference shares, debentures, retained earnings and long-term loans. Basically, there are two types of long-term funds :

1. Owner’s capital and
2. Borrowed capital

All these types of finance have to be in the right proportion in order to ensure an optimum capital structure.

Question 4.
What is money market ?
Answer:
Money market is that makret where seller and purchaser or buyer of money are available. Money buyers are those who takes loans to produce goods or services and money sellers are those who gives loan to industries.

Question 5.
Write two elements of marketing.
Answer:
Two elements of marketing :

1. To distribution of goods and services
2. To creation of utilities.

Question 6.
What do you mean by pricing of a product ?
Answer:
It is an important work of marketing management to determining the price of marketable goods. A producer or manufacturer determines the price after comprehensive study.

Question 7.
Advertising confuses the buyers. How ?
Answer:
Some traders or businessmen advertises with misrepresentation false statement and fraudulent advertisement because of this buyer get confused and tence wrong decision about trading and got cheated. They confused to what is to buy or not.

Question 8.
What is entrepreneurship ?
Answer:
Enterpreneurship is combination of a skill view point, thinking. Technique and work method.

Question 9.
Explain the role of Henry Fayol in management.
Answer:
Fayol developed a functional approach’ to management. Realising the universal nature of management problems he developed general principles of management and administration this ideas are contained in his monograph” General and industrial administration.” This book throws light on the following points :

1. Classification of Industrial Activities
2. Management qualities and training
3. General Principles of Management
4. Elements of Management.

Question 10.
Write the limitations of planning ?
Answer:
Following are the limitation of planning :

1. Forecasting may go wrong : Financial plans are prepared by taking into account the expected situation in the future. Since the future is not predictable and thing may not happen as these are for casted the utility of planning is limited.
2. Regidity : Once a plan is prepared, it becomes difficult to change it. A change in the circumstances may demand change in the financial plan but managers may not like so.
3. Problem of Co-ordination : Finance functions is the most important of all the functions.

Question 11.
Can accountability be delegated ?
Answer:
According to principle of absolute responsibility authority can be delegated but responsibility can not be delegated by a manager. The manager remains responsible or accountable to his own superior for the tasks which he may assign to his subordinates. Every superior is responsible, for the acts of his sub-ordinates to whom he delegates authority for any work.

Question 12.
What do you mean by staffing ?
Answer:
Staffing may be defined as’the managerial function of hiring and developing the required personnel to fill in various position in the organisation. It is concerned with employing the right type of people and developing their skill through training. It focuses on maintaining and improving the competence and performance of the personnel in the organisation.

Question 13.
Mention any three elements of Directing.
Answer:
Following are the three elements of directing :

1. Supervision : It implies instructing, observing, monitoring and guiding the sub-ordinates at work place to ensure that plans and procedures are implemented as intended.
2. Leadership : It involves ability to use non- coersive influence on the activities, goals and motivation of others for achieving organisational objectives.
3. Motivation : Motivation is a mental state. It is a driving force that people to action and continues them in action. Motivation is the set of forces that causes people to behave in certain ways.

Question 14.
What is meant by ‘Profit sharing’ ?
Answer:
Profit sharing : When a firm earned profit. It divided the profit amongest their partners on the basis of equal ratio or on the ratio as determined in the deed. It is called profit sharing

Question 15.
What are the different traditional techniques of controlling ?
Answer:
Following are the technique of controlling :

1. Break-even point: Break even point is an important tool which is used by managerial control. That level of sales or production where there is no loss or no profit is creled break even point.
2. pecial report and analysis : Generally special report and analysis is used to control special types of problems.
3. Budgetary control : Budgetary control is a composition between Predicted data and actual data.

Question 16.
Explain the importance of Financial planning.
Answer:
Importance of Financial Planning :

1. Co-ordination : This is done by laying down financial objectives, plans and programmed which are coherent with each other. The plan is communicated to all managers in different departments and ensures that finds are alloted to each department according to their requirements. All these factors help in achieving co – ordinations.
2. Financial control : Financial planning is the basis of financial control. It sets standards against which performance of the financial plan can be compared. The resulting deviations can be corrected and also prevented.

Question 17.
State any three characteristics of fixed capital.
Answer:
Following are the three features of fixed capital :

1. It remains for long period in business.
2. Fixed capital is used to purchase of fixed assets examples, e.g. land, building, machines etc.
3. The quantity of fixed capital is depend on the nature of business.

Question 18.
Define and explain the term ‘stock exchange’.
Answer:
Definition of stock-exchange : “Stock exchange means any body of individuals, whether incorporated or not contributed for the purpose of assisting, regulating or controlling the business of buying selling and dealing in securities.
“Stock-exchange are marketing places where securities that have been listed there on may be bought and sold for either investment or speculation.” – Pyle, Marketing Principles.

Question 19.
What is the concept of marketing mix ?
Answer:
Marketing mix refers to combination of four basic elements, viz., Product mix, Price, promotion and place known as four P’s marketing.

1. Product mix : Product mix refers to anything which is offered to the public for sales. It may be a physical object service or an idea.
2. Price mix : Goods are sold for a price consumer’s are very sensitive to price changes.
3. Promotion mix : Promotion includes all those activities which a business performs to persuade and motivate people to buy their product.
4. Place : Place mix refers to the activities that are involved in transferring ownership to customers and to make products available at the right time and please.

Question 20
What are the different types of labels ?
Answer:
The label is an information they wrapper or seal attached to a product or product’s package.
Types of label :

1. Brands label
2. Grade labels
3. Descriptive cu-informative labels.

Question 21.
What do you mean by controlling ?
Answer:
Controlling is the process through which managers assure that the actual activities conform to the planned activities.

Question 22.
Write any two advantages of budgetary control.
Answer:
Two advantages of Budgetary Control :

1. Budgets serve as a target.
2. Budgeting helps to express diverse action.

Question 23.
What is the concept of gross working capital ?
Answer:
Gross working capital means the investment in all current assets namely; cash, inventories, receivables and prepaid expenses taken together.

Question 24.
What are the two segments of capital market ?
Answer:
The two segment of capital market :

1. Organised Capital Market
2. Unorganised Capital Market

Question 25.
Name any three Non-Governmnet Organisations (NGO’s).
Answer:
Name of three Non-government Organisation :

1. Consumer Association, Kolkata
2. Karnataka Consumer Service Society, Bangluru.
3. VOICE, New Delhi.

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.
Define the concept of management. Discuss its importance.
Answer:
The term ‘management’ has been used in different sense. Sometimes it is used in the sense of managing the ‘Group of management personnel’ in an organisaiton. At other times, management refers to the process of planning organisation, staffing, directing co-ordinating and controlling.

1. Definition of management : “To manage is to forcast and to plan to organise to command to co-ordinate and controll” – Henry Feyol.
2. “Management means the decision making.” – Rose Moore

Importance of management :

1. Maximum results with maximum resources : Management tries to secure the maximum results through the use of maximum efforts and resources.
2. Realisation of personel objectives : Some industrial concern are downed on account of skirikes and lockout. Such situation mainly arise when there is mismanagement on the part of managers.
3. Economic growth : Management is a vital force for boosting the economic growth of a country.
4. Protection of investors interests : Most of the organisaiton are run by employees-managers. They look after the interests of investors, shareholders, debenture holders etc.

Question 27.
Discuss the nature and purpose of organisation.
Answer:
Organisation is structural relationship by which an enterprise is bound together and the frame work in which individual effort is controlled.
Name of Organisaiton :

1. Formal relationship : Different type of relationship exists in formal organisation. These are senior subordinate, lateral and employee relationships.
2. Establishing co-ordination : Formal organisation structure establishes co-ordination among vairous departments and smothers the work of the entire organisation.
3. Delibrately designed structure : Formal organisation is delibrately designed by the top management. Therefore, everything done in it is official.
4. Focus on work : It lays emphasis on the accomplishment of work rather than on social relationship.

Purpose of Organisation :

1. Identification of activities and their division
2. Grouping the activities into departments.
3. Assigning duties
4. Establishing work-relationship.

Question 28.
What do you mean by recruitment ? Explain the external sources of recruitment.
Answer:
Meaning and definition of recruitment : Recruitment function is concerned with discovering the sources of. manpower required and tapping these sources.

1. “Recruitment is the process of searching for prospective employees and stimulating them- to apply for jobs in the organisation.” – Flippo.
2. “It is the process of attracting poential employees to the company.”

External sources of recruitment:

1. Factory gate : For recruitment of semi-skilled and unskilled employee a notice is put at the factory gate specifying the requirements of various types of workers.
2. Waiting list : Very often organisations prepare and maintain a waiting list of employees from the application of those condidates who had applied but could not be selected.
3. Employees recommendation : A large number of organisation asks their present employees to recommend the name of suitable candidates as anol when a vacancy arises.
4. Private placement agencies : These are of recent origin. Now-a-days reputed private placement agencies such as Tata Consultancy Service are doing commendable job in this field.
5. Employment exchange : Employment exchanges have been set up by government in metropolitan and other big cities.
6. Media advertisement : By far advertisement in leading newspaper, magazines of external recruitment for skilled and specialised jobs.

Question 29.
What is the meant by the term ‘supervision’ in management ? Explain briefly the role of a supervisor.
Answer:
Supervision means overseeing the work of the subordinates. Every managers has to guide and control his sub-ordinates while they are performing the task assigned to them. We can therefore say that supervision refers to the direct and immediate guidance and control of sub-ordinates in the performance of their tasks. Terry and Franklin define supervision as, guiding and sources to accomplish stated work outputs.”

Role of Supervisor in brief :

1. Face-to-face contact
2. An important link
3. Creating congenial atmosphere
4. Giving guidance
5. Ensures quality,
6. Giving feedback
7. Keeping up the organisational commitments
8. Suggesting Taining Programmes.

Question 30.
What do you mean by Financial Planning? Discuss the importance of Financial Planning in financial management.
Answer:
Financial Planning : Financial Planning means deciding in advance how much to spend on what to spend, according to the finds at four disposal. According to Worker and Baughan, “Financial planning pertains only to the functions of finance and includes the determination of the firms financial objectives, formulating and promulagating financial policies and developing financial procedures.”

Element determining the financial planning or Important of Financial Planning :

1. Nature of Industry : The nature of industry of business plays decisive role in drafting of financial plan. A capital intensive industry like cement, paper or fertilizer requires more capital while a labor intensive enterprise requires less amount of capital.
2. Status of unit: This step includes the evolution of increment characteristics of the wait like age size, market area, scope and nature of the field then reputation of management etc.
3. Flexibility : Flexibility and not the rigidity should be the main principal to be followed in the financial planning.
4. Plans for the future growth : Firms expect to grow larger in size as they grow old. So while undertaking current financing decisions the factors of future growth should be suitable weighted.
5. Capital structure : The capital structure of the company must be of high grade securities. It should be diversified but balanced.

Question 31.
Explain briefly any five factors to be considered in determining working capital requirements of an enterprise.
Answer:
Following are the factors which are determining working capital :

1. Size of business : Larger size 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 organisation.
2. Production cycle : Production cycles means the time span between the purchase of raw material and its conversion into finished goods. If the production cycle is small the need for working capital will also be small.
3. Production policy : The need for working capital is also determined by production policy. The demand for certain products is seasonal. Two types of production policies may be adopted for such products. Firstly, the goods may be produced in the months of demand and Secondly, the goods may be produced through the year.
4. 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.
5. Efficiency of management : Efficiency of management is also a significance factor to determine the level of working capital. Management can reduce the need for working capital by the efficient utilization of resources. If an accelerate tea pace of cash cycle and there by use the same amount working capital again very quickly.

Question 32.
Explain briefly the benefits of advertising to manufacturers and society.
Answer:
(a) Advantages to manufacturer :

1. Advertising creates demand for the producers of a company
2. It helps salesman to secure orders easily,
3. A good image of the firm is created
4. New products can be introduced easily through advertising.

(b) Advantages to society :

1. It provided direct employment to a large number of people engaged in designing, writing and insuring advertisement
2. It is an important source of income for newspapers, magazine, radio and television. It helps the press in reducing the cost of publications.

Question 49.
Explain any six rights of consumers.
Answer:
Following are the six rights of consumers.

1. Right to safety : Consumers have the right to protected against the marketing of goods and services which are hazardous to life and property.
2. Right to information : The consumer protection act lays down that every consumer has the right to be informed about the quality, quantity, potency, purity and standard of goods and services.
3. Right to choose : Every consumer has the right to choose the goods of his/her liking. Consumers have right to be assured, wherever possible access to a variety of goods and services at competitive prices.
4. Right to heard : In case a consumer has been exploited, he/she has the right to be heard and be assured that he/she interests would receive due consideration at appropriate forums.
5. Right to seek redressal : The consumers have the right to seek redress against unfair trade practices or unsecruplous exploitation.
6. Right to consumer education : Consumer can seek information about the existing acts and agencies set up for their protection.

Question 33.
What are the main functions of an entrepreneur ?
Answer:
Following are the function of entrepreneur :

1. Take risk
2. Power to devisionl,
3. Managerial ability
4. Function of renovation
5. Creation of capital
6. Per capital income
7. To increase the opportunities of employment
8. Development of area.

Bihar Board 12th Business Studies Model Papers

Bihar Board 12th Business Studies Model Question Paper 2 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 questiion carries 1 (one) mark. [50 x 1 = 50]

Question 1.
Henri Fayol was a ___________
(a) Scientist
(b) Mining engineer
(c) Accountant
(d) Production engineer
Answer:
(b) Mining engineer

Question 2.
Of all managerial activities planning is the :
(a) Beginnings
(b) End
(c) Beginning & end both
(d) None of these
Answer:
(c) Beginning & end both

Question 3.
Staffing is:
(a) part of organisation
(b) function of Management
(c) part of personnel Management
(d) all of the above
Answer:
(d) all of the above

Question 4.
How are the principles of Management formed ?
(a) In a laboratory
(b) By experiences of managers
(c) By experiences of customers
(d) By propagation of social scientists
Answer:
(b) By experiences of managers

Question 5.
The following is not an objective of
Management: .
(a) earning profits
(b) growth of the organisation
(c) providing employment
(d) policy making
Answer:
(c) providing employment

Question 6.
Controlling is the aspect of Management:
(a) theoretical
(b) practical
(c) mental
(d) physical
Answer:
(b) practical

Question 7.
Commercial bill is written :
(a) by purchaser
(b) by seller
(c) by bank
(d) by the government
Answer:
(c) by bank

Question 8.
Marketing concept is :
(a) Production-oriented
(b) Sales-oriented
(c) Customer-oriented
(d) All the three
Answer:
(b) Sales-oriented

Question 9.
Which of the following statements best describes the principle of ‘Division of Work’
(a) Work should be divided into small tasks.
(b) Labour should be divided
(c) Resources should be divided among jobs
(d) It leads to specialisation
Answer:
(a) Work should be divided into small tasks.

Question 10.
Management control is done :
(a) by lower level managers
(b) by middle level managers
(c) by top level managers
(d) by all level managers
Answer:
(d) by all level managers

Question 11.
Money market deals in :
(a) Short term funds
(b) Medium term funds
(c) Long term funds
(d) None of these
Answer:
(a) Short term funds

Question 12.
Treasury Bills are basically :
(a) An instrument to borrow short term funds
(b) An instrument to borrow long-term funds
(c) An instrument of capital market
(d) None of the above
Answer:
(a) An instrument to borrow short term funds

Question 13.
Policy formulation is the function of:
(a) top level managers
(b) middle level managers
(c) operational Management
(d) all of the above
Answer:
(a) top level managers

Question 14.
Consumer dispute settlement agencies are :
(a) District Forum
(b) State commission
(c) National commission
(d) All the above
Answer:
(d) All the above

Question 15.
There is no discipline in ___________ Organisation :
(a) formal
(b) divisional
(c) functional
(d) informal
Answer:
(d) informal

Question 16.
Goods may be purchased on the basis of:
(a) inspection
(b) pattern and sample
(c) description & brand
(d) all of the above
Answer:
(d) all of the above

Question 17.
The cheapest source of Finance is:
(a) debenture share
(b) equity share capital
(c) preference share
(d) retained earning
Answer:
(b) equity share capital

Question 18.
Supervisor is ___________ of the workers.
(a) friend
(b) guide
(c) philosopher
(d) all of these
Answer:
(b) guide

Question 19.
Budget refers to :
(a) Planned target of performance
(b) Use of handling future activities
(c) Systematic action and allocation of resources
(d) Statement of expected results expressed in numerical terms
Answer:
(d) Statement of expected results expressed in numerical terms

Question 20.
In which form of Management science is :
(a) Pure Science
(b) Soft Science
(c) Semi Science
(d) None of these
Answer:
(b) Soft Science

Question 21.
Recruitment in the life of Organisation is done :
(a) Once
(b) Twice
(c) Occasionally
(d) Continuosly
Answer:
(d) Continuosly

Question 22.
Marketing means:
(a) Transfer of ownership
(b) Formation of marketing policies
(c) Salesmanship and sales promotion
(d) All of the above
Answer:
(b) Formation of marketing policies

Question 23.
Which of the following is not a principle of Management given by Taylor ?
(a) Science, not rule of thumb
(b) Functional foremanship
(c) Co-operation, not individualism
(d) Harmony, not discord
Answer:
(b) Functional foremanship

Question 24.
Which of the following is not a controlling technique ?
(a) Break-even anaysis
(b) Cash flow statement
(c) Budget
(d) Managerial Audit
Answer:
(b) Cash flow statement

Question 25.
In India Entrepreneurial development programme is:
(a) Necessary
(b) Unnecessary
(c) Wastage of time
(d) wastage of money
Answer:
(a) Necessary

Question 26.
The disputes coming under Consumer Protection Act are:
(a) Dispute as to shares of company
(b) Dispute as to service
(c) Dispute as to sale of defective goods by the seller
(d) None of these
Answer:
(c) Dispute as to sale of defective goods by the seller

Question 27.
Stock exchange protects the interest of:
(a) Investors
(b) Company
(c) Government
(d) None of these
Answer:
(a) Investors

Question 28.
Which of the following is not an element of promotion mix ?
(a) Advertisement
(b) Personal selling
(c) Sales Promotion
(d) Product Development
Answer:
(d) Product Development

Question 29.
Co-ordination is:
(a) Voluntary
(b) Necessary
(c) Unnecessary
(d) Wastage of time
Answer:
(b) Necessary

Question 30.
Principle of Management are :
(a) dynamic
(b) flexible .
(c) Universal
(d) all of above
Answer:
(d) all of above

Question 31.
___________ refers to those general statement which are decided for the guidance of the employees while taking decision.
(a) objectives
(b) strategy
(c) policies
(d) All of the above
Answer:
(b) strategy

Question 32.
In the process of delegation, accountability cannot be:
(a) shared
(b) delegated
(c) neither (a) & nor
(b) (d) both (a) and (b)
Answer:
(b) (d) both (a) and (b)

Question 33.
Management itself expands :
(a) Through delegation
(b) Through centralisation
(c) Through decentralisation
(d) Through all
Answer:
(a) Through delegation

Question 34.
Control is the ___________ function of the Management:
(a) first
(b) last
(c) third
(d) second
Answer:
(b) last

Question 35.
The leader takes work from his subordinates :
(a) by tact
(b) by rod
(c) by threatening
(d) none of these
Answer:
(a) by tact

Question 36.
The foremost need of development in a country is of:
(a) Physical Resources
(b) Economic Resources
(c) Human Resources
(d) Efficient Management
Answer:
(b) Economic Resources

Question 37.
A good plan is :
(a) Rigid
(b) Expensive
(c) flexible
(d) Time consuming
Answer:
(b) Expensive

Question 38.
Which of the following is not a staffing function :
(a) Planning
(b) recruitment
(c) selection
(d) training
Answer:
(a) Planning

Question 39.
Effective controlling is :
(a) static
(b) determined
(c) dynamic
(d) all the above
Answer:
(c) dynamic

Question 40.
Liquidity is created by :
(a) Organised market
(b) Unorganised market
(c) Primary Market
(d) Secondary Market
Answer:
(d) Secondary Market

Question 41.
Which of the following is not the tool of sales promotion ?
(a) Samples
(b) Prize in packet
(c) Coupons
(d) Publicity
Answer:
(c) Coupons

Question 42.
Modern approach of financial Management is :
(a) procurement of funds
(b) utilisation of funds
(c) (a) and (b) both
(d) None of these
Answer:
(c) (a) and (b) both

Question 43.
The functions of Entreprener are :
(a) To imagine business idea
(b) To study project feasibility
(c) To set up enterprise
(d) All of above
Answer:
(c) To set up enterprise

Question 44.
Which of the following is function of packaging ?
(a) Protection
(b) convenience
(c) Identification
(d) All of the above
Answer:
(d) All of the above

Question 45.
Planning is not the remedy of all business evils, because:
(a) planning is generally biased & time consuming
(b) planning is goal oriented
(c) planning enables us to face future uncertainties
(d) planning improves competitive strength
Answer:
(c) planning enables us to face future uncertainties

Question 46.
Which of the following is a determinant of Capital structure ?
(a) Cash Flow Statement
(b) Interest Coverage Ratio
(c) Debt Service Coverage Ratio
(d) All of the above
Answer:
(b) Interest Coverage Ratio

Question 47.
Which of the followiwng is not a characteristic of Entrepreneurship ?
(a) Risk taking
(b) Innovation
(c) Creative activity
(d) Managerial training
Answer:
(d) Managerial training

Question 48.
Grapevine Communication is :
(a) informal
(b) formal
(c) written
(d) none of these
Answer:
(a) informal

Question 49.
The foremost stock exchange in the world was established in:
(a) Delhi.
(b) London
(c) America
(d) Japan
Answer:
(b) London

Question 50.
State Commission can settle consumer disputes :
(a) up to 5 lakh Rs.
(b) up to 10 lakh Rs.
(c) up to 20 lakh Rs.
(d) Above 20 lakh Rs.
Answer:
(d) Above 20 lakh Rs.

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.
Does mere planning ensure success ?
Answer:
Does mere planning ensure success ? yes planning ensure success merely if following features are consiist in planning.

1. Planning must be simple and understandable.
2. planning must be according to the employee.
3. Planning must be felxible
4. Planning must be consist element of selection.
5. Draft separate planning for excution of planning.

Question 2.
What is meant by lay-off ?
Answer:
A lay off is the temporary suspension of employment of an employee or more commonly, a group of employees for business reasons. Such as personnel management or down sizing an organisation.

Question 3.
What is meant by investment decision ?
Answer:
A determination made by direction and management as to how, when, where and how much capital will be spent on investment opportunities, is called investment decesion.

Question 4.
Why NSEI is known as Model Exchange ?
Answer:
National stock exchange is the first stock exchange in India. The security transaction in stock exchange of India is very transmitted and simple so it is called model exchange.

Question 5.
The word communication has been derived from Latin word ‘Communist.’ What does it mean ?
Answer:
The word communication is derived from the latin word communist meaning “common”.

Question 6.
“Management is a soft science.” How ?
Answer:
Management is a soft science because management have principles like science as they can applied anytime, any where but it is not exact science because principle are applied according to situations.

Question 7.
What is meant by Authority ?
Answer:
Authority is refers to the power to take decisions.

Question 8.
Why is it said that ‘Controlling is blind without planning ?
Answer:
Under the system of controlling actual work performance is compared with the standards. Hence, if the standards are not determined there is no justification left for control, and the standards are determined under planning. It is therefore, said that control is blind without planning or it is with out any base.

Question 9.
What is meant by Channels of Distribution ?
Answer:
A distribution channel refers to the path or route through which goods and services traval to get from the place of production or manufacture to the final users. It has at its center transportation and logistical considerations.

Question 10.
Why it is said that principles of Management are universal ?
Answer:
Management is an universal phenomenon in the same that it is common and essential element in all enterprises. Every group effort requires setting objectives, making plans, handling people, co – ordinating and controlling activities achieving goass and, evaluating performance directed towards organisational goals.

Question 11.
What is meant by the ‘Right to Choose’ to a consumer ?
Answer:
Following are the six rights of consumers.

1. Right to safety : Consumers have the right to protected against the marketing of goods and services which are hazardous to life and property.
2. Right to information : The consumer protection act lays down that every consumer has the right to be informed about the quality, quantity, potency, purity and standard of goods and services. ,
3. Right to choose : Every consumer has the right to choose the goods of his/her liking. Consumers have right to be assured, wherever possible access to a variety of goods and services at competitive prices.
4. Right to heared : In case a consumer has been exploited, he/she has the right to be heared and be assured that he/she interests would receive due consideration at appropriate forums.
5. Right to seek redressal : The consumers have the right to seek redressal against unfair trade practices or unsecruplous exploitation.
6. Right to consumer education : Consumer can seek information about the existing acts and agencies set up for their protection.

Question 12.
What is meant by ‘Leadership’ ?
Answer:
Leadership may be defined as the ability to exert interpersonal influence by means of communication towards the achievement of a goal.

Question 13.
State any two difference between Advertising and Personal Selling.
Answer:
Advertising :

1. one-way communication.
2. Pull strategy.
3. Mass Media.

Personal Selling :

1. Two-way communication.
2. Push-strategy
3. Sales personnel.

Question 14.
What is meant by-On-the job training ?
Answer:
On the job training : The training of operations is largely undertaken through on the job methods on the other hand managers are trained by taking new courses under both on the job and off the job method.

Question 15.
State two points of 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. Supervisor assumes responsibility for the accomplish ment of task. Undertaken and motivates his fellow workers.

Question 16.
What are the two components of Capital market ?
Answer:
Following are the two componants of capital market.

1. Organised capital market.
2. Unorganised capital market

Question 17.
What is Budgetary control ?
Answer:
Budgetary control refers to how well managers utilize budgets to monitor and control costs and operations in given accounting period. In other words, budgetary control is a process for managers to set financial and performance goals with budgets, compare the actual results, and adjust performance, as it is needed.

Question 18.
State any two features of Scientific Management.
Answer:
Following are the two features of scientific management.

1. Systematic Approach.
2. Brings complete mental change.

Question 19.
What do you mean by Entrepreneurship ?
Answer:
Enterpreneurship is an innovative function. It is a leadership rather than an ownership.

Question 20.
How “scale of operations” affect the requirement of fixed Capital ?
Answer:
The companies which are operating at large scale require mare fixed capital as they need more machineries and other assets where as small scale enterprise need less amount of fixed capital.

Question 21.
“Sales promotion makes advertising effective.” How ?
Answer:
Once the samples of a particular product reach to the consumers through sales promotion the advertisement of the same product gets more effective.

Question 22.
Give two advantages of functional Organisation.
Answer:
Following are the advantages of functional organisation.

1. Benefits of specification.
2. Co-ordination is established.

Question 23.
Give a definition of management.
Answer:
According to George R. Terry and Stephen G. Franklin, “Management is a distinct process, consisting of activities of planning, organizing, actuating and controlling performed to determine and accomplish stated objectives with the use of human beings and other resources.”

Question 24.
Differentiate between time study and motion study.
Answer:
The main points of differences between Time study and Motion study are as follow-

1. Motion study involves the study of motions on operation while the time study notes the time involved in carrying out of each element of operations
2. The main aim of motion study is to reduce wastage of time and material scraping the unnecessary movements whereas the time study aims at fixing the standard time of carrying out a job/work
3. Time study is not suitable for workers where quality is prime consideration. Motion study is suitable for all types of jobs/work.

Question 25.
What is functional organisation ? What are its characteristics ?
Answer:
Functional organisation is developed on the basis of important of functions of the organisation.
Following are the features/Advantages of functional organisations :

1. System in place of haphazardness
2. Effective and easy supervision
3. Better cordination
4. Economical
5. Human development

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.
“Training is beneficial both for the Organisation as well as for the employees”. Explain any two benefits of training towards the Organisation and any two towards the employees.
Answer:
Benefits of training : Training is necessary activity all organisation. It plays a large part in determining the efficiency of the organisation. Some of the major benefits of training and development are enumerated below :
(a) Benefits to the organisation :

1. Increases productivity : It helps to improve employee’s knowledge and skills, which in turn increases the quality and quantity of production. Higher productivity means higher profitability for the organisation.
2. Reduced supervision : Training gives employees greater confidence. Trained employees need less supervision. They require freedom to handle their jobs without close supervsion. With reduced supervision, a manager can widen his span of control and spend greater time on more non-routine issues of the department. Properly trained employees are more self- reliant because they are more confident about what do and how to do it. The employees need not learn by trial and error method.

(b) Benefits to the Employees :

1. Acqueisition of new skills : A trained employees acquires new attitude and skills, which enhance his market value. The acquisition of new knowledge increase his prospects within and outside the organisation for higher jobs.
2. Higher Earnings: Trained employees can perform better and thereby earn more.
3. Safety: Trained employees are less prove to accidents as they handle the machines carefully.
4. Self-confidence : Training enables the employee to approach and performs his job with enthusiasm.
5. Promotion : Through training, employees can develop himself and earn quick promotion.
6. Adoptability : Trained employees adopt to changes in work procedures and methods easily.

Question 27.
Every manager has to take three major decisions while performing the final function. Explain.
Answer:
The three main financial decisions which are generally taken by a finance manager are as under:

1. Investment Decision : It refers to the selection of assets in which funds will be invested by the business. Assets which are obtained by the business are of two types, i.e. Long term assets and short-term assets. On this basis, investment decision is also divided into two parts :
   • Long-term Investment decision
   • Short-term Investment decision.
2. Financial Decision: It refers to the determination as to how the total funds required by the sources. Long-term financial sources chiefly include equity share capital, preference share capital, retained earnings, debentures Long-term Loan etc. For taking financial decision, an analysis of the cost and benefits of all the sources is made.
3. Dividend Decision : It refers to the determination of how much part of the earning should be distributed among shareholders by the way of dividend and how much should be retained for meeting future needs as retained earnings.

Question 28.
Explain briefly the factors determining the amount of fixed Capital.
Answer:
Factors affecting the requirement/need of fixed capital:-

1. Nature of Business It has been observed that trading concerns require less fixed capital in comparison to manufacturing enterprises. The reason is that manufacturing enterprises require more machines and tools , where as these may not be required by trading concerns.
2. Size of Business Size of business also determines the amount of fixed capital larger the size of the business, the heavier would be the requirement for fixed capital.
3. System of production Production can take place manually or mechanically. Mechanization requires more amount of fixed capital as compared to manual processes.
4. Owner ship of fixed capital If an enterprises wishes to have its own fixed assets, it will have to arrange a lot of money to buy them, on the other hand, if an enterprises, decline to have the fixed assets on hire, will not be required to arrange for heavy amount of fixed capital.
5. System of marketing An enterprises, doing direct marketing with out the intervention of whole sealers and retailers has to invest heavily on own retail outlets and on suitable supply of vehicles. Therefore, its need will be much more than those that depend on intermediaries for marketing purposes.
6. Range of production An enterprises producing all the parts of a product requires more amount of fixed capital than the one which produces vital parts and gets other parts produced from outside.

Question 29.
How functional structure differs from a divisional structure ?
Answer:
Function Structure :

1. Formation is based on functions.
2. Functional specialization.
3. Difficult to fix on a department
4. Difficult, as each functional manager has to report to the top management.
5. Functions are not duplicated hence economical.
6. Difficult for a multiproduct company.

Divisional structure :

1. Formation is based on product lines and is supported by functions.
2. Product specialization.
3. Easy to fix responsibility for performance.
4. Easier, autonomy as well as the change to perform multiple functions help in managerial development.
5. Duplication of resources in various departments hence costly.
6. Easy, because all functions related to a particular product are integrated in on department.

Question 30.
State the factors affecting the requirements of fixed capital.
Answer:
The factors affecting the requirements of fixed capital are as follows :

1. Nature of business : Some types of business need more capital and some less.Manufacturing industries need more fixed capital than trading concerns.
2. Size of business unit : Fixed capital or requirements depend on the size of business.If the size is big.it will need more fixed capital.For smaller organisation the need will be less.
3. Nature of goods manufactured : The amount of fixed capital also depends on articles to be manufactured. For manufacturing industrial goods or machines the need for capital will be more than the industries engaged in manufacture of consumer goods.
4. Amount of preliminary expenses : If the promoters have to spend more on preliminary expenses like commission on sale of shares or debentures or as underwriting commission etc.there will be more need of fixed capital.
5. Method of production and technology used : If the enterprise uses modern technology like fully automatic plant for production or uses imported , machinery ,the fixed capital needs will be high.
6. Mode of purchase of fixed assets : Fixed capital requirements will be more if fixed assets are purchased in cash and less if purchased on credit or on hire purchase or on installment payment system.

Question 31.
What is meant by ‘Monetary Incentives’ ? State any three types of monetary incentives which contribute to the performance of employees.
Answer:
Financial Motivation : Financial motivation are those which are accociated with money. They include wages and salaries, fringes benefits, bonus, retirement benefits, etc. However, such incentives may not always prove to be motivating. In many cases, management may have to increase the financial incentives to keep the workers with the organisation. This can be appreciated from the practice of making wages and salaires competitive between various enterprises so as to attract and maintain good work force.

Money is a real motivating factor when the physiological and security needs of the workers have not been fully satisfied. Money plays a significant role in satisfying these needs. Therefore, management can use financial incentives for motivation. Money also helps in satisfying the social needs of employees to some extent because money is often recognised as a symbol of status, respect and power.

Besides money is an important means of achieving a ‘minimum standard of living althought this ‘minimum’ has the tendency to go up as people become more affluent. But this should not lead one to conclude that money will always be a motivating factor to all people. To some people, importance of money may be reduced after a certain stage and non-financial rewards may become more important. They are motivated by money only up to the stage they are struggling for satisfying their physiological and security needs.

Money provides for the satisfaction of physiological and safety needs only, which have been called hygienic factors by Herzberg. Hygienic include wages and salaries and other fringe benefits. The presence of these factors at a satisfactory level prevents job dissatisfaction. They do not provide ‘on-the-job satisfaction’ to the employees and therefore, can not be considered as motivational factors. According to Herzberg, in order to motivate the employees, it is necessary to provide for the satisfaction of their ego, social and self-actualisation needs.

But these needs are present, generally, in employees in the higher positions, who get higher monetary rewards and are not motivated by increased monetary benefits. In case of employees at the operative levels, money certainly plays a significant role in motivating them because their survival and safety depends on it.

Following are included in financial incentives :

1. Salaries and wages
2. Bonus (out of firm’s Profit)
3. Premium (share in economics due to increase in production).

Question 32.
Which qualities of a good leader will you like to have as a Manager ?
Answer:
The qualities of good leader are as follows :

1. Physical features : Physical features like height, weight health, appearance determine the physical personality of an individual health and endurance help a leader to work hard which inspires others to work with same tempo.
2. Knowledge : A good leader should have required knowledge and competence. Only such person can instruct subordinates correctly and influence them.
3. Integrity : A leader should posses high level of integrity and honesty. He should be a role model to others regarding the ethics and values.
4. Initiative : A leader should have courage and initiative. He should not wait, for opportunities come to his way, rather he should grab the opportunity and use it to the advantage of organisation.
5. Communication skills : A leader should be a good communicator. He should have the capacity to clearly explain his ideas and make the people to understand his ideas.
6. Motivation skills : A leader should be an effective motivator. He should understand the needs of people and motivate them through satisfying their needs.
7. Self confidence : A leader should have high level of self confidence. He should not loose his confidence even in most difficult times.
8. Decisiveness : Leader should be decisive in managing the work. Once he is convinced about a fact, he should be firm and should not change opinions frequently.
9. Social skills : A leader should be sociable and friendly with his colleagues and followers. He should understand people and maintain good human relations with them.

Question 33.
What is planning ? Which steps are taken by management in the process of planning ?
Answer:
Meaning of Planning – Planning is the selection of the best course of action out of the available alternatives and deciding to achieve the objective through the best course so chosen.

Definition – According to Alfred and Beatty, “Planning is the thinking process, the organised foresight, the vision based on facts and experience that is required for intelligence action.”

Following steps are taken by management in planning :

1. Setting objectives – The first step in planning exercises is setting the objectives, providing the rationale for undertaking various activities as well as indicating the direction of efforts. Moreover, objectives point to the end-result of planning activity. The objectives provide guidelines for many vital decisions relating to resources allocation, schedule of work, nature of actions, etc.

2. Establishing the planning premises – Once goals have been set, the second step involves establishing the planning premises or assumptions. It consists of forecasting future conditions and events which are likely to have bearing on the pursuit of goals like market demand for goods, cost of raw materials, state of technology, intensity of competition, government policies,interest rates, tax rates, etc.

3. Identifying alternative courses of action – When the forecasts are available and premises are established, a number of alternative courses of action have to be considered.

4. Evaluating alternative course – Planning requires that each alternative should be evaluated taking into account the relevant facts and the pros and cons of each alternative. The merits and demerits as well as consequences of each alternative course of action must be examined before a choice is made.

5. Selecting an alternative – After evaluation of various available alternative courses, the time comes for selecting the best plan and to implement it practically. The plan will be justified best in terms of feasibility, profitability and with least adverse outcomes. Sometimes a firm may also go for combination of plans instead of selecting one best course.

6. Formulation of derivative plans – Having decided upon the course of action, it is necessary that detailed plans and programmers should be drawn up including specific plans for different type of activities.These are known as derivative plans.

7. Implement of plan/Securing co-operation – Planning is essentially goal-oriented. Hence,the plans formulated must be implemented effectively. For this purpose, co-operation of all the members of the organisation is required. Accordingly, plans must be of what is proposed to be done and why. Many a time useful suggestions and ideas are received when plans are communicated to the concerned workers. Employees are motivated to execute the plan to the best of their ability.

8. Follow up – As planning is a continuous process, existing plans are received at intervals to ensure their relevance and effectiveness. As the plans are implemented, certain facts often come to light which were not even thought of earlier.