Priyanshu

Bihar Board 12th Hindi Model Papers

Bihar Board 12th Hindi 100 Marks Model Question Paper 1

समय 3 घंटे 15 मिनट
पूर्णांक 100

परिक्षार्थियों के लिए निर्देश

1. परीक्षार्थी यथा संभव अपने शब्दों में ही उत्तर दें।
2. दाहिनी ओर हाशिये पर दिये हुए अंक पूर्णांक निर्दिष्ट करते हैं।
3. इस प्रश्न पत्र को पढ़ने के लिए 15 मिनट का अतिरिक्त समय दिया गया है।
4. यह प्रश्न पत्र दो खण्डों में है, खण्ड-अ एवं खण्ड-ब।
5. खण्ड-अ में 50 वस्तुनिष्ठ प्रश्न हैं, सभी प्रश्न अनिवार्य हैं। (प्रत्येक के लिए । अंक निर्धारित है) इनके उत्तर उपलब्ध कराये गये OMR शीट में दिये गये वृत्त को काले/नीले बॉल पेन से भरें। किसी भी प्रकार का व्हाइटनर/तरल पदार्थ/ब्लेड/नाखून आदि का उत्तर पत्रिका
6. में प्रयोग करना मना है, अथवा परीक्षा परिणाम अमान्य होगा।
7. खण्ड-ब में कुल 15 विषयनिष्ठ प्रश्न हैं। प्रत्येक प्रश्न के समक्ष अंक निर्धारित हैं।
8. किसी तरह के इलेक्ट्रॉनिक यंत्र का उपयोग वर्जित है।

खण्ड-अ

वस्तुनिष्ठ प्रश्न

प्रश्न संख्या 1 से 50 तक वस्तुनिष्ठ प्रश्न है जिसके साथ चा विकल्प दिए गए हैं, जिनमें से एक सही है । अपने द्वारा चुने गए सह विकल्प को OMR शीट पर चिह्नित करें। (50 x 1 = 50)

बहुविकल्पिक उत्तरों में से सही उत्तर दें।

प्रश्न 1.
‘बातचीत’ शीर्षक के चरनाकार हैं :
(a) जगदीश चन्द्र माथुर
(b) बालकृष्ण भट्ट
(c) रामचन्द्र शुक्ल
(d) शमशेर बहादुर सिंह
उत्तर:
(b) बालकृष्ण भट्ट

प्रश्न 2.
“उषा’ शीर्षक कविता के रचयिता है:
(a) सुभद्रा कुमारी चौहान
(b) ज्ञानेन्द्रपति
(c) जयशंकर प्रसाद
(d) शमशेर बहादुर सिंह
उत्तर:
(d) शमशेर बहादुर सिंह

प्रश्न 3.
‘अर्द्धनारीश्वर’ शीर्षक के रचनाकार हैं :
(a) रामचन्द्र शुक्ल
(b) जगदीश चन्द्र माथुर
(c) हजारी प्रसाद द्विवेदी
(d) रामधारी सिंह ‘दिनकर’
उत्तर:
(d) रामधारी सिंह ‘दिनकर’

प्रश्न 4.
‘प्रेम के पीर’ के कवि कौन हैं :
(a) जायसी
(b) नाभादास
(c) जयशंकर प्रसाद
(d) सुभद्रा कुमार चौहान
उत्तर:
(a) जायसी

प्रश्न 5.
‘रोज’ शीर्षक कहानी के लेखक कौन हैं :
(a) अज्ञेय
(b) मलयज
(c) रामधारी सिंह ‘दिनकर’
(d) नामवर सिंह
उत्तर:
(a) अज्ञेय

प्रश्न 6.
इनमें से कौन-सी रचना प्रसाद जी की नहीं हैं :
(a) देवदासी
(b) कामायनी
(c) झरना
(d) आँसू
उत्तर:
(c) झरना

प्रश्न 7.
पं0 चन्द्रधर शर्मा ‘गुलेरी’ की कहानी का नाम है :
(a) तिरिछ
(b) जूठन
(c) उसने कहा था
(d) इनमें से कोई नहीं
उत्तर:
(c) उसने कहा था

प्रश्न 8.
श्री कृष्ण ने किस पर आक्रमण किया था ?
(a) रावण पर
(b) कंस पर
(c) सहस्रबाहु पर
(d) इनमें से किसी पर नहीं
उत्तर:
(b) कंस पर

प्रश्न 9.
निम्नांकित में से कौन-से रचनाकार बिहार के हैं ?
(a) शमशेर बहादुर सिंह
(b) रामधारी सिंह दिनकर
(c) मोहन राकेश
(d) जगदीश चन्द्र माथुर .
उत्तर:
(b) रामधारी सिंह दिनकर

प्रश्न 10.
तुलसीदास अपना पेट कैसे भरते थे ?
(a) कविताएँ करके
(b) कथावाचन से
(c) रामकथा गाकर
(d) राम श्री राम का नाम लेकर
उत्तर:
(d) राम श्री राम का नाम लेकर

प्रश्न 11.
‘शिक्षा’ शीर्षक निबंध के निबंधाकार कौन हैं ?
(a) जे० कृष्णमूर्ति
(b) उदय प्रकाश
(c) मलयज
(d) मोहन राकेश
उत्तर:
(a) जे० कृष्णमूर्ति

प्रश्न 12.
‘गाँव का घर’ कविता के कवित हैं :
(a) ज्ञानेन्द्रपति
(b) जयशंकर प्रसाद
(c) रघुवीर सहाय
(d) इनमें से कोई नहीं
उत्तर:
(a) ज्ञानेन्द्रपति

प्रश्न 13.
ओ सदानीरा’ शीर्षक में किस महापुरुष की चर्चा है ?
(a) बाल गंगाधर तिलक
(b) महात्मा गांधी
(c) सदन मोहन मालवीय
(d) चन्द्रशेखर आजाद’
उत्तर:
(b) महात्मा गांधी

प्रश्न 14.
‘भगवान श्री कृष्ण’ किस कवि के पूज्य थे ?
(a) सूरदास
(b) तुलसीदास
(c) नाभादास
(d) कबीरदास
उत्तर:
(a) सूरदास

प्रश्न 15.
‘जूठन’ शीर्षक की विद्या क्या है?
(a) कहानी
(b) शब्द-चित्र
(c) आत्मकथा
(d) इनमें से कोई नहीं
उत्तर:
(a) कहानी

प्रश्न 16.
‘जयशंकर प्रसाद’ की श्रेष्ठ कृति है :
(a) कामायनी
(b) लहर
(c) आँसू
(d) चित्राधार
उत्तर:
(a) कामायनी

प्रश्न 17.
निम्नांकित में कौन अज्ञेय का उपन्यास नहीं है :
(a) अपने-अपने अजनबी
(b) नदी के द्वीप
(c) शेखर : एक जीवन
(d) त्रिवेणी
उत्तर:
(d) त्रिवेणी

प्रश्न 18.
‘मुक्तिबोध’ का जन्म हुआ था :
(a) रामगढ़ में
(b) भोपाल में
(c) श्योपुर में
(d) वाराणसी में
उत्तर:
(c) श्योपुर में

प्रश्न 19.
‘मालती’ किस शीर्षक की पात्रा है ?
(a) रोज की
(b) जूठन की
(c) ओ सदानीरा की
(d) तिरिछ की
उत्तर:
(a) रोज की

प्रश्न 20.
सुभद्रा कुमारी चौहान की मृत्यु का कारण था :
(a) महामारी
(b) कार दुर्घटना
(c) फाँसी
(d) गोली
उत्तर:
(b) कार दुर्घटना

प्रश्न 21.
‘रजनीश’ का संधि-विच्छेद है :
(a) रज + नीश
(b) रजनी + ईश
(c) रजणी + इश
(d) राज + ईश
उत्तर:
(b) रजनी + ईश

प्रश्न 22.
‘पावन’ का सन्धि-विच्छेद है :
(a) पा + वन
(b) पो + अन
(c) पौ + अन
(d) इनमें से कोई नहीं
उत्तर:
(c) पौ + अन

प्रश्न 23.
‘सत्कार’ का संधि-विच्छेद है :
(a) सत + कार
(b) सत् + कार
(c) सम् + कार
(d) स + आकार
उत्तर:
(b) सत् + कार

प्रश्न 24.
“विद्यालय का संधि-विच्छेद है :
(a) विद्या + आलय
(b) विद्या + लय
(c) विद्या + अलय
(d) इनमें से कोई नहीं
उत्तर:
(a) विद्या + आलय

प्रश्न 25.
‘दिनेश’ का संधि विच्छेद है :
(a) दिन + ईश
(b) दिन + इश
(c) दिन + नेश
(d) दीन + ईश
उत्तर:
(a) दिन + ईश

प्रश्न 26.
‘आगमन’ में कौन-सा उपसर्ग है?
(a) अ
(b) आ
(c) आग्
(d) इनमें से कोई नहीं
उत्तर:
(b) आ

प्रश्न 27.
‘पूर्णिमा’ के कौन-सा प्रत्यय है ?
(a) इमा
(b) ईमा
(c) एमा
(d) इनमें से कोई नहीं
उत्तर:
(a) इमा

प्रश्न 28.
‘जलज’ कौन-सा समास है ?
(a) तत्पुरुष
(b) अव्ययीभाव
(c) कर्मधारय
(d)द्वन्द्व
उत्तर:
(a) तत्पुरुष

प्रश्न 29.
‘देवालय’ कौन-सा समास है ?
(a) कर्मधारय
(b) अव्ययीभाव
(c) तत्पुरुष
(d) इनमें से कोई नहीं
उत्तर:
(c) तत्पुरुष

प्रश्न 30.
‘लम्बोदर’ कौन-सा समास है ?
(a) बहुव्रीहि
(b) तत्पुरुष
(c) कर्मधारय
(d) द्वन्द्व
उत्तर:
(a) बहुव्रीहि

प्रश्न 31.
‘रात-दिन’ कौन-सा समास है :
(a) द्विगु
(b) बहुव्रीहि
(c) द्वन्द्व
(d) इनमें से कोई नहीं
उत्तर:
(c) द्वन्द्व

प्रश्न 32.
‘प्रतिदिन’ कौन-सा समास है :
(a) अव्ययीभाव
(b) बहुव्रीहि
(c) द्वन्द्व
(d) इनमें से कोई नहीं
उत्तर:
(a) अव्ययीभाव

प्रश्न 33.
‘आग’ का पर्यायवाची शब्द है :
(a) व्योम
(b) पयोज
(c) अग्नि
(d) पीयूष
उत्तर:
(c) अग्नि

प्रश्न 34.
‘ईश्वर’ का पर्यायवाची शब्द है :
(a) आत्मा
(b) परमात्मा
(c) देवेन्द्र
(d) शंकर
उत्तर:
(b) परमात्मा

प्रश्न 35.
‘अन्धकार’ का विलोम है :
(a) प्रकाश
(b) दिन
(c) उजला
(d) सूर्य
उत्तर:
(a) प्रकाश

प्रश्न 36.
‘अदेह’ का विलोम है :
(a) विदेह
(b) सुदेह
(c) सदेह
(d) इनमें से कोई नहीं
उत्तर:
(c) सदेह

प्रश्न 37.
‘गोरा’ का विलोम है :
(a) गौर
(b) काला
(c) कुरूप
(d) श्यामला
उत्तर:
(b) काला

प्रश्न 38.
‘ठण्ढ़ा’ का विलोम है :
(a) अग्नि
(b) गर्म
(c) वाष्प
(d) चिनगारी
उत्तर:
(b) गर्म

प्रश्न 39.
“दिवाकार’ का विलोम है :
(a) निशाकर
(b) निशाचर
(c) रजनी
(d) तमस
उत्तर:
(a) निशाकर

प्रश्न 40.
‘साधारण’ का विपरीतार्थक शब्द है :
(a) असामान्य
(b) असाधारण
(c) अस्वाभाविक
(d) इनमें से कोई नहीं
उत्तर:
(b) असाधारण

प्रश्न 41.
‘जिसका आचरण अच्छा है’ के लिए एक शब्द है :
(a) दुराचारी
(b) सदाचारी
(c) सबल
(d) बलवान
उत्तर:
(b) सदाचारी

प्रश्न 42.
‘जिसके पास धन हो’ के लिए एक शब्द है :
(a) निर्धन
(b) निर्दयी
(c) कठोर
(d) जिज्ञासु
उत्तर:
(a) निर्धन

प्रश्न 43.
‘घोड़ा बेचकर सोना’ मुहावरा का अर्थ है :
(a) गहरी नींद में सोना
(b) निश्चिंत होना
(c) अधिक मुनाफा. कमाना ।
(d) व्यापार करना
उत्तर:
(b) निश्चिंत होना

प्रश्न 44.
‘चैन की बंशी बजाना’ मुहावरा का अर्थ है :
(a) मनोरंजन करना
(b) सुखी रहना
(c) समृद्ध होना
(d) आराम से रहना
उत्तर:
(b) सुखी रहना

प्रश्न 45.
‘राई का पहाड़ बनाना’ मुहावरा का अर्थ है :
(a) चुगली करना
(b) छोटी बात को बढ़ा चढ़ा कर कहना
(c) असंभव को संभव करना
(d) इनमें से कोई नहीं
उत्तर:
(b) छोटी बात को बढ़ा चढ़ा कर कहना

प्रश्न 46.
‘हाथ पाँव मारना’ मुहावरा का अर्थ है:
(a) प्रयास करना
(b) नदी में तैरना
(c) पिटाई करना
(d) इशारा करना
उत्तर:
(a) प्रयास करना

प्रश्न 47.
‘हवा में बातें करना’ महावरे का अर्थ है:
(a) धीरे चलना
(b) तेज दौड़ता
(c) बहुत तरक्की करना ।
(d) इनमें से कोई नहीं
उत्तर:
(c) बहुत तरक्की करना ।

प्रश्न 48.
‘धर्म’ का विशेषण है:
(a) धार्मिक
(b) धर्मज्ञ
(c) धर्मा
(d) इनमें से कोई नहीं
उत्तर:
(a) धार्मिक

प्रश्न 49.
‘राष्ट्र’ का विशेषण है :
(a) राष्ट्रीयता
(b) राष्ट्रीय
(c) राष्ट्रवाद
(d) राष्ट्रसंघ
उत्तर:
(b) राष्ट्रीय

प्रश्न 50.
‘चरित्र’ का विशेषण है :
(a) चारित्रिक
(b) चरित्रवान
(c) सुचरित्र
(d) इनमें से कोई नहीं
उत्तर:
(a) चारित्रिक

खण्ड-ब

विषयनिष्ठ प्रश्न

प्रश्न 1.
किसी एक पर निबंध लिखें (1 x 8 = 8)
विद्यार्थी जीवन में खेल कूद, होली, दहेज प्रथा, सामाजिक अभिशाप, आधुनिक भारतीय नारी, विज्ञान का चमत्कार।
उत्तर:
(क) विद्यार्थी जीवन और खेलकूद :
खेलों का जीवन में उतना ही महत्त्वपूर्ण स्थान है जितना अन्न, विद्या अथवा मनोरंजन का । प्राचीनकाल में खेलों की विविध प्रतियोगिताएँ, होती थीं। धीरे-धीरे प्रतियोगिताएँ जिला स्तर से प्रदेश और फिर प्रदेश से देश अथवा राष्ट्र-स्तर पर आ पहुँची। आज यह स्थिति है कि क्रिकेट, हॉकी, मुक्केबाजी, तीर-अंदाजी, बास्केटबॉल, फुटबॉल, मल्ल-युद्ध आदि का विश्व-खेलों में ऊँचा स्थान है। विश्व-खेलों के माध्यम से विश्व-भर के खिलाड़ी एक स्थान पर इकट्ठे होते हैं। विश्व-खेलों का आयोजन विश्व-एकता की दृष्टि से महत्त्वपूर्ण है । खेल मैत्री-भावना को बढ़ावा देते हैं । खेलों के आयोजन प्रतिभा के विकास में सहायक होते हैं । जीवन की नीरसता खेलों से टूटती है। प्रतिभाशाली खिलाड़ियों को आगे बढ़ने का मौका मिलता है। खेलों को जीवन में महत्त्व देते समय नैतिक आचरण करने की आदत डालनी चाहिए । जीवन में खेलों को महत्त्वपूर्ण स्थान न देने का मुख्य कारण खेलों के विषय में उचित प्रशिक्षण न देना है। योग्य खेल-विशेषज्ञों के सान्निध्य में खिलाडियों की प्रतिभा में निखार वैज्ञानिक परिवेश में होता है।

खेलों से हमारा शरीर हृष्ट-पुष्ट तथा सुगठित बनता है। आज के भोले-भाले बालकों को कल के भारत का महान युवा बनना है। इसीलिए स्वामी विवेकानंद ने कहा था, “मेरे बच्चो ! तुम्हें गीता नहीं, फुटबॉल चाहिए । मैं चाहता हूँ कि तुम्हारी मांसपेशियाँ लोहे की हों, नसें फौलाद की हों और मस्तिष्क उसी पदार्थ का बना हो, जिससे कि आकाश में कौंधने वाली बिजली बनी होती है।’
खेलों से हमारा भरपूर मनोरंजन होता है, हमारी कार्यक्षमता बढ़ती है। यदि मनुष्य नियमपूर्वक बराबर खेलता रहे तो वह आजीवन युक्त बना रहता है। खेलों से हममें सहनशीलता, संवेदनशीलता, संगठन, सहयोग, विश्वास, साहस, अनुशासन तथा आज्ञाकारिता की भावना जगती है।

आज का युग भौतिक युग है। आज के मशीनी युग में खेलों का महत्त्व और भी बढ़ जाता है। अच्छा स्वास्थ्य अच्छे मन का भी सूचक है-‘अच्छे तन अच्छा मन’ इसीलिए तो कहा गया है। खेलों को जीवन के
लिए वरदान कहा जा सकता है। स्पष्ट है कि स्वस्थ तन के अभाव में स्वस्थ मस्तिष्क का बनना संभव नहीं है। शरीर को ऐसा बनाने में खेलों का अपना महत्त्व है। खेल जीवन को सार्थक तथा रोचक बनाते हैं।

(ख) होती अथवा मेरा प्रिय त्योहार :
होली मेरा प्रिय त्योहार है। यह अपनी झोली में रंग और गुलाल लेकर आती है। यह उल्लास, आनंद और मस्ती का त्योहार है। होली चैत मास के कृष्णपक्ष की प्रतिपदा को मनाई जाती है । इसके एक दिन पहले (प्राय:) होलिकादहन होता है। होलिकादहन की पीछे होलिका (हिरण्यकश्यपु की बहन) हिरण्यकश्यपु और उसके विष्णुभक्त पुत्र प्रह्लाद की जो पौराणिक कथा है, वह सर्वविदित है। समाजशास्त्रियों को कथन है कि कृषि-प्रधान देश भारत के सारे पर्व फसल के साथ जुड़े हुए हैं। होली रबी फसल की आशा (की शुखी) में मनाई जाती है। अगजा’ के दिन ‘संवत’ में लोग गेहूँ की कच्ची बालियाँ भूनकर खाते हैं । ‘होली’ का अर्थ दुग्धपूर्ण अनाज का भूना हुआ रूप होता है। अगजा’ (होलिकादहन) के लिए गाँवों और शहरों में निश्चित स्थान पर होलिकादहन होता है। निश्चित समय पर लोग एकत्र होते हैं। बच्चों द्वारा एकत्र किए गए लकड़ी-गोयठे और घास-पात में आग लगाई जाती है। आग लगते ही लोग ढोल पर थाप दे-देकर होली गाने लगते हैं। अजीब आनंद का वातावरण छा जाता है। वहाँ हँसी-ठिठोली भी खूब होती है। कभी-कभी बच्चे और युवक अतिरिक्त उत्साह में किसी की चौकी या झोपड़ी ही ‘आगजा’ में डाल देते हैं। यह अशोभनीय है। इससे रंग में भंग होता है।

दूसरे दिन खूब धूमधाम से होली शुरू होती है। रंग, गुलाल, नए वस्त्र और रंग-अबीर से रंगे-पुते मुस्कुराते-हँसते चेहरे-यही है इस पर्व की पहचान । घर-घर तरह-तरह के पकवान पकते हैं। सभी एक-दूसरे से आनंदविह्वल होकर मिलते हैं। इस दिन कोई किसी का शत्रु नहीं होता । भाँग और शराब पीकर तथा लोगों पर रोड़े-भरी कीचड़ फेंककर इस त्योहार का मजा किरकिरा नहीं करना चाहिए । जीवन में रस का संचार करनेवाली होली का अभिनंदन तभी सार्थक होगा जब हम संप्रदाय, जाति, धर्म तथा ऊँच-नीच की भावना और विद्वेष से ऊपर उठकर सबको गले लगाने के लिए तैयार होंगे।

(ग) दहेज-प्रथा ….. सामाजिक अभिशाप :
विवाह के समय कन्या के माता-पिता वर पक्ष को जो वस्राभूषण, धन तथा समान देते हैं, उसे दहेज कहते हैं। प्राचीनकाल में इसे ‘यौतक’ या ‘स्रीधन’ कहा जाता था। ‘मनुस्मृति’ में कहा गया है, “मातुस्तु यौतक यत् स्यात् कुमारी भाग एवं सः।” प्राचीनकाल में ‘यौतक’ (दहेज) देने की प्रथा तो थी, पर उसमें किसी प्रकार का दबाव नहीं था। ऐसा नहीं था कि वरपक्ष के लोग कन्यापक्ष के लोगों से जबरदस्ती धन लेते हों। यह पूर्णत: कन्यापक्ष की समार्थ्य और श्रद्धा पर आधृत था।

पर, समय के साथ ही सारी स्वस्थ परंपराएँ लुप्त होती गयीं और उनके स्थान पर रूढ़ियों ने अपना अधिकार जमा लिया। कन्या के विवाह के अवसर पर श्रद्धा से दी जानेवाली राशि अब अनिवार्यता हो गई यहीं से प्रारंभ होता है दहेज का क्रूर नाटक जिसने आज सम्पूर्ण भारतीय समाज को अपने खूनी पंजों के आघात से लहूलुहान कर दिया है। धन के अभाव में पिता अपनी पुत्रियों का विवाह योग्य वर से नहीं कर पाता । वह किसी तरह अपना कर्तव्य पूरा करना चाहता है। किशोरी कन्याओं का विवाह अधेड़ या कभी-कभी उनके पिता की उम्र के पुरुषों से कर दिया जाता है। आज भारतीय समाज में दहेज के कारण ही अविवाहित कन्याओं की संख्या दिन-प्रतिदिन बढ़ती जा रही है।

वह समाज की गिरावट का ही प्रमाण है कि आज कन्या की श्रेष्ठता, शील, सौंदर्य और गुणों से नहीं बल्कि उसके माँ-बाप के धन से आँकी जाती है। कन्या की कुरूपता दहेज की चमक-दमक में छिप जाती है। दहेज आधुनिक युग में घोर अभिशाप बन गया है । इस सामाजिक कलंक को दूर करने के लिए शिक्षित युवक-युवतियों को आगे आना होगा। सामाजिक संस्थाओं और सरकार को भी इस दशा में कारगर कदम उहाना चाहिए । दहेज प्रथा को दूर करने में महिलाओं की सक्रिय भूमिका अत्यंत महत्त्वपूर्ण है। उन्हें नारियों में जागरूकता, चेतना और दृढ़ इच्छाशक्ति भरनी होगी ताकि नारियाँ इस कुप्रथा के विरुद्ध संघर्ष कर समाज में उचित आदर प्राप्त कर सकें।

(घ) आधुनिक भारतीय नारी :
दुनिया के कुछ भागों में यह विश्वास प्रचलित है कि जब परमात्मा ने मानव को उत्पन्न किया तो मानव ने स्वयं को एकाकी पाया, मनुष्य ने परमात्मा से साथी माँगा, परमात्मा ने वायु से शक्ति, सूर्य से गर्मी, हिम से शीत, पारे से चंचलता, तिलियों से सौन्दर्य और मेघ-गर्जन से शोर लेकर स्त्री पुरुष की ‘शरीराद्ध’ और अर्धांगिनी मानी गयी तथा ‘श्री’ और ‘लक्ष्मी’ के रूप में वह मनुष्य के जीवन को सुख और समृद्धि से दीप्त और पुंजित करने वाली कही गयी, उसका आगमन पुरुष के लिए शुभ, सौरभमय और सम्मानजनक था।

हिन्दू समाज में कोई भी धार्मिक कार्य बिना पत्नी के सम्पन्न नहीं होता, इसीलिए वह ‘धर्मपत्नी’ अथवा सहधर्मिणी भी कही जाती है । ‘मनु’ के अनुसार केवल पुरुष कोई वस्तु नहीं, वह अपूर्ण है। स्री, स्वदेह तथा सन्तान ये तीनों ही मिलकर पुरुष (पूर्ण) होता है। गृह की शोभा और सम्पन्नता स्त्री के व्यक्तित्व का विकास एक दूसरे का पूरक है। नारी स्नेह और सौजन्य की प्रतिमा है, त्याग और समर्पण की मूर्ति है, दुष्ट मर्दन में चण्डी, संग्राम में कैकेयी, श्रद्धा में शबरी, सौन्दर्य में दमयन्ती, सुगृहिणी में सीता, अनुराग में राधा, विद्वता में गार्गेयी और राजनीति में लक्ष्मीबाई के तुल्य है। नारी का अपमान मानवता का सबसे बड़ा अपराध है। उसकी उपेक्षा मनुष्य के अस्तित्व को जर्जर, नीरस और व्यर्थ पर देती है।

शिक्षा के प्रसार के साथ-साथ नारी को भी स्वच्छन्द परिवेश में श्वाँस लेने का पूर्णसुखद अवसर सुलभ अवश्य हुआ है किन्तु आर्थिक असमानता, शिक्षा के अभाव में ग्रामीण नारियों का जीवन ‘चूल्हा चक्की’ से ऊपर नहीं उठ सका है और आज भी नारकीय यन्त्रणा ही उनकी हिस्से में है। ‘गृहलक्ष्मी’ तो ये अवश्य है किन्तु तिजोरी की चाभी पुरुष के पास ही रहती है, ‘अन्नूपर्णा’ अवश्य हैं वे किन्तु कौन-सी ‘सब्जी’ बनेगी, पति की ही बात चलती है। धनलोलुपों द्वारा नारी-शरीर का खुला क्रय-विक्रय आज भी सामयिक है। कुछ शहर मर्दो में चाहे वह भाई हो या पति, इस नरक से उबरने की इच्छा भी नहीं मानते । उनका तर्क है कि पेट भरा होने के बाद ही सूझता है कि कौन धंधा सही है, कौन गलत भारत में तमाम शहर ऐसे हैं जहाँ औरतों को आज भी जिन्दा माँस की तश्तरी से ज्यादा महत्त्व नहीं दिया जाता है। हर शहर में वेश्यालय सिनेमा घरों की तरह हाउस-फूल जा रहे हैं। ये वेश्यायें देह सुख के लिए ऐसा नहीं करतीं, अपितु आर्थिक असमानता एवं दुरावस्था से वे अभिशप्त हैं।

भारतीय संस्कृति का परित्याग कर, पश्चिमी अनुकरण कर नारी चैन से नहीं कर सकती है। समाज के साथ-साथ नारी का भी दायित्व है कि अपने प्रति, अपने कर्तव्यों के प्रति, अपने आदर्शों के प्रति सचेष्ट रहे। उसे शकुन्तला भी बनना होगा, सीता भी, राधा भी बनना होगा और लक्ष्मीबाई भी, कस्तूरबा भी, सरोजिनी, नायडू भी। भारतीय नारी का आदर्श महान।

(ङ) विज्ञान: वरदान का अभिशाप :
आज विज्ञान के महत्त्व को, उसको उपादेयता को नकारा नहीं जा सकता है। चाहे वह घर का रसोईघर हो या समर-भूमि; विज्ञान के चमत्कार तथा प्रभाव स्पष्ट रूप से परिलक्षित होते हैं। प्रकृति पर विज्ञान की विजय-यह एक किंवदंती नहीं, एक प्रत्यक्ष सत्य है । चन्द्रमा पर मनुष्य का अभियान, ट्यूब बेबी, रॉकेट, अणुबम आदि विज्ञान की उत्कृष्ट देन हैं। सैकड़ों-हजारों मील लम्बी दूरियाँ भी मनुष्य पैदल ही तय करता था । आज वायुमान के सहारे हम कुछ ही घंटों में भारत से लंदन पहुँच जाते हैं। कभी चन्द्रमा यात्रा की बात कोरी कल्पना समझी जाती थी, परन्तु जब बन्द मानव चन्द्रमा की सतह पर उतरे तो सम्पूर्ण विश्व दाँतों तले ऊँगलियाँ दबाकर रह गया । आज जीवन का कोई भी पक्ष ऐसा नहीं है जहाँ विज्ञान की किरणें नहीं पहुँची हों।

विज्ञान हमारे लिए वरदान सिद्ध हुआ है। इसकी उपयोगिता जीवन के हर क्षेत्र में सिद्ध है। क्षण-क्षण, पल-पल हम विज्ञान के चमत्कारों का नजारा देखते हैं, संबंधित कहानियाँ सुनते हैं। कुछ महत्त्वपूर्ण उपलब्धियों का संकेत करके हम उसके महत्त्व की उपादेयता का सहज अनुभव कर सकते हैं। विज्ञान के अद्भुत चमत्कारों ने एक नयी क्रांति पैदा कर दी है, एक नया अध्याय जोड़ दिया है।

आवागमन के क्षेत्र में विज्ञान की उपलब्धियाँ विशिष्ट एवं विलक्षण हैं। आज से सैकड़ों वर्ष पूर्व एक जगह से दूसरी जगह जाना गहन समस्या था। आज विज्ञान के कारण इस क्षेत्र में क्रान्तिकारी परिवर्तन हुए हैं। रेलगाड़ियाँ, मोटरकार, बसें, वायुयान आदि इतनी तेज सवारियाँ निकल आयी हैं कि बातों-ही-बातों में हम लम्बी-लम्बी दूरियाँ तय कर लेते हैं। तार, टेलीफोन, वायरलेस आदि यंत्रों के आविष्कार के कारण हम घर बैठे मुम्बई, कोलकाता, लंदन में रहनेवाले लोगों से बाते कर लेते हैं। नदी, समुद्र, पहाड़ आज हमारे आवागमन के मार्ग में किसी प्रकार को अवरोध उत्पन्न नहीं कर सकते।

चिकित्सा के क्षेत्र में विज्ञान की उपलब्धियों ने संजीवनी बूटी का काम किया है। पुराने जमाने में छोटी-छोटी बीमारी के कारण लोगों की मृत्यु हो जाती थी।

आज शायद ही ऐसा कई रोग है, जिसकी दवा सुलभ नहीं है, जिसका निदान संभव नहीं है। क्या यह विलक्षण चमत्कार नहीं है कि विश्व से चेचक, प्लेग, मलेरिया आदि रोगों का उन्मूलन हो गया। आज बड़े-बड़े असाध्य रोगों की भी अच्छी एवं प्रभावकारी औषधियाँ निकल रही हैं। दिन-प्रतिदिन नये-नये प्रयोग हो रहे हैं, नये-नये उपकरण एवं नयी-नयी जीवनरक्षक औषधियाँ निकल रही है। मनुष्य का हृदय विकृत या क्षतिग्रस्त हो जाने पर उसे बदल दिया जा सकता है और मनुष्य को नयी जिन्दगी दी जा सकती? अंधे को आँखों की रोशनी, विकलांगों के विकृत अंगों में सुधार, दिल और दिमाग में परिवर्तन वैज्ञानिक चमत्कारों की ही देन हैं।

आवागमन या चिकित्सा ही नहीं, प्रायः सभी क्षेत्रों में विज्ञान की बड़ी-बड़ी उपलब्धियाँ सामने आयी हैं । चन्द्रमा पर मानव की विजय से लेकर पाकशालाओं एवं शयनकक्षों में आराम एवं सुख-सुविधाओं की सारी चीजों की व्यवस्था विज्ञान के ही चमत्कार हैं। रेडियो, सिनेमा, टेलिविजन, वीडियो आदि सारी-की-सारी चीजें विज्ञान की ही देन हैं। कम्प्यूटर ने एक नये युग की शुरूआत की है।

प्रत्येक वस्तु के दो पक्ष होते हैं-श्वेत और श्याम । विज्ञान भी इसका अपवाद नहीं है। विज्ञान यदि वरदान है तो अभिशाप भी बना है। विज्ञान ने यदि हमारे अधरों पर मुस्कुराहट बिखेरी है तो इसने हमारी आँखों में अश्रुकरण भी संजोये हैं। विज्ञान ने परमाणु बम तथा अनेक गैसों, हथियारों एवं शस्त्रास्त्रों का आविष्कार किया है, जो मानव समुदाय का समूल विनाश करते हैं । हिरोशिमा और नागासाकी पर मानवता के ध्वंस का तांडव नृत्य क्या हम भूल पाये हैं ? स्वयं बमपर्षक जहाज के चालकों ने पश्चाताप किया है।

आज बड़े-बड़े देश परमाणु-शक्ति की खोज इसलिए नहीं कर रहे हैं कि उनका प्रयोग मनुष्य के कल्याण एवं शान्तिपूर्ण प्रयोजनों के लिए किया जायेगा, वरन् उनका प्रयोग मानवता को ध्वस्त करने के लिए किया जायेगा। संहार अस्त्र-शस्त्रों के निर्माण पर सभी देश अपनी बजट राशि में वृद्धि कर रहे हैं। बड़े-बड़े देश एवं महाशक्तियाँ इन्हीं संहारक हथियारों के बलबूते पर छोटे तथा कमजोर देश पर अपना आधिपत्य बनाये रखना चाहती है।

इन बमों के विस्फोट से निकली विषैली गैसों के कारण वातावरण दूषित हो गया है, अनेकानेक बीमारियाँ फैल रही हैं। विशेषज्ञों का कथन है कि यदि इसी प्रकार ये विषैली गैसें वातावरण को दूषित करती रही तो आनेवाले बच्चे शारीरिक एवं मानसिक रूप से विकृत होंगे। मशीन के अधिकाअधिक अविष्कार के कारण बेकारी की समस्या बढ़ती जा रही है। जहाँ मशीनों का अधिक उपयोग हो रहा है, वहाँ मनुष्य बेकार होते जा रहे हैं।

विज्ञान एक वरदान भी है और एक अभिशाप भी । विज्ञान अपने-आपमें न तो अभिशाप है और न वरदान । विज्ञान का वरदान होना या अभिशाप होना वैज्ञानिकों और राजनीतिज्ञों पर निर्भर करता है। सबसे मूल बात यह है कि हम इसका प्रयोग किस प्रकार तथा किसलिए करते हैं।

यदि हम विज्ञान का प्रयोग मानव-कल्याण के लिए करते हैं तो हमारे लिए सबसे बड़े वरदान है और यदि हम इसका प्रयोग नर-संहार के लिए करते हैं, तो यह मानव-जीवन का सबसे बड़ा अभिशाप है।

प्रश्न 2.
किन्हीं दो की सप्रसंग व्याख्या करें : (4 x 2 = 8)

(क) आत्महत्या एक घृणित अपराध है । यह पूर्णतः कायरता का कार्य है।
उत्तर:
प्रस्तुत पंक्तियाँ भगत सिंह लिखित कहानी एक लेख और एक पत्र से ली गई हैं। इन पंक्तियों में लेखक कहते हैं, कोई भी व्यक्ति जो आत्महत्या करेगा वह थोड़ा दुख, कष्ट सहने के चलते करेगा। वह अपना समस्त मूल्य एक ही क्षण में खो देगा । इस संदर्भ में उनका विचार है कि मेरे जैसे विश्वास और विचारों वाला व्यक्ति में मरना कदापि सहन नहीं कर सकता । हम तो अपने जीवन का अधिक से अधिक मूल्य प्राप्त करना चाहते हैं। हम मानवता की अधिक से अधिक सेवा करना चाहते हैं। संघर्ष में मरना एक आदर्श मृत्यु है । प्रयत्नशील होना एवं श्रेष्ठ और उत्कृष्ट आदर्श के लिए जीवन दे देना कदापि आत्महत्या नहीं कही जा सकती। आत्महत्या को कायरता’ इसलिए कहते हैं कि केवल कुछ दुखों से बचने के लिए अपने जीवन को समाप्त कर देते हैं । इस संदर्भ में वे एक विचार भी देते हैं कि विपत्तियाँ व्यक्ति को पूर्ण बनाने वाली होती हैं।

(ख) नारी और नर एक ही द्रव्य की ढ़ली दो प्रतिमाएँ हैं।
उत्तर:
प्रस्तुत पंक्ति रामधारी सिंह दिनकर के निबंध अर्द्धनारीश्वर से ली गई है। निबंधकार दिनकर का मानना है कि नर-नारी पूर्ण रूप से
समान हैं एवं उनमें एक के गुण दूसरे के दोष नहीं हो सकते । अर्थात् नरों  में नारियों के गुण आएँ तो इससे उनकी मर्यादा हीन नहीं होती बल्कि

उसकी पूर्णता में वृद्धि होती है । दिनकर को यह रूप कहीं देखने को नहीं मिलता है । इसलिए वे क्षुब्ध हैं। उनका मानना है कि संसार में सर्वत्र पुरुष हैं और स्री-स्री । वे कहते हैं कि नारी समझाती है कि पुरुष के गुण सीखने से उसके नारीत्व में बट्टा लगेगा। इसी प्रकार पुरुष समझता है कि त्रियोचित गुण अपनाकर वह ौण हो जायेगा। इस विभाजन से दिनकर दुखी है। यही नहीं भारतीय समाज को जानने वाले तीन बड़े चिंतकों रवीन्द्रनाथ, प्रेमचंद, प्रसाद के चिंतन से भी दुखी हैं । दिनकर मानते हैं कि यदि ईश्वर ने आपस में धूप और चाँदनी का बँटवारा नहीं किया तो हम कौन होते हैं आपसी गुणों को बाँटने वाले ।

(ग) पूरब पश्चिम से आते हैं।
नंगे बूचे नर-कंकाल
सिंहासन पर, बैठा, उनके
तमगे कौन लगाता है।
उत्तर:
प्रस्तुत पंक्तियाँ रघुवीर सहाय की कविता ‘अधिनायक’ से ली गई हैं। कवि भारतीय लोकतांत्रिक व्यवस्था पर साहसपूर्ण प्रतिक्रिया, इसके कथित परिवेश व्यंग्य करता है। भारतीय समाज में फैली अव्यवस्था, ऊँचा-नीच समानता-असमानता पर कलरा कुठाराघात करते हुए पूँजीवादी

जनतंत्र की आड़ में किये जा रहे शोषण, दमन और अन्याय के खिलाफ विद्रोह करता है।

कवि लोकतांत्रिक व्यवस्था पर चोट करते हुए, उस पर कटाक्ष करते हुए कहता है कि इस व्यवस्था में एक तरफ तो चारों दिशाओं से भूख की चीत्कार सुनाई दे रही है, बदन पर पहनने के लिए वस्त्र नहीं है, तो दूसरी ओर सत्ता पर कुंडली मारे लोग शोषण के चक्र चला रहे हैं।

कवि लोकतंत्र के मूल्यों के भ्रष्टीकरण से आहत है। इसीलिए कवि मनुष्य और मनुष्य के बीच समानता और सामाजिक न्याय की लड़ाई के प्रति अपने को प्रतिशत किए हुए है। वह हर ऐसे हर अमानवीय और क्रूर हरकत के खिलाफ आवाज उठाता है जिससे समानता और भाइचारे के जनवादी मूल्य खंडित होते हैं।

(घ) बड़ा कठिन है बेटा खोकर
माँ को अपना मन समझाना।
उत्तर:
प्रस्तुत पंक्तियाँ सुभद्रा कुमारी चौहान की कविता ‘शोक गीत पुत्र वियोग’ से ली गई हैं। इन पंक्तियों में कवयित्री की असीम पुत्र प्रेम की व्यंजना हुई है। कविता माँ का हृदय बड़ा कोमल होता है। वह एक पुत्र को पाने के लिए तरह-तरह की मिन्नतें माँगती हैं। पत्थर को देवता मानकर शीश नचवाती है। नौ माह तक कष्ट झेलती हुई अनेक तकलीफ सहती हुई उसे पाती है । उसे पाने के बाद उसे पढ़ाती-लिखाती, संस्कार देती है। इस तरह पुत्र उसके जीवन का अहम हिस्सा बन जाता है। वह रोता है तो मनाती है, चुप कराती है।

इस तरह पुत्र-प्रेम में वह बँध जाती है। परन्तु इसी बीच जब उसके पुत्र की असमय मृत्यु हो जाती है तो उसका जीवन सूना-सूना हो जाता है । वह पुत्र प्रेम के कारण बेचैन सी हो जाती है। उसे लगता है बिछुड़े हुए पुत्र से एक बार वह मिल लेती, पलभर के लिए प्यार कर लेती । परन्तु यह सब नहीं हो पाता। इसलिए वह मन को समझा नहीं पाती । बेटा खोकर एक माँ को अपने मन को . समझाना कठिन हो जाता है।

प्रश्न 3.
अपने कॉलेज के प्रधानाचार्य को एक आवेदन पत्र लिखें, जिसमें कॉलेज परिसर में हिन्दी-दिवस आयोजित करने की अनुमति की माँग हो। (1 x 5 = 5)

उत्तर:
सेवा में,
प्रधानाचार्य महोदय
पटना कॉलेजिएट स्कूल, पटना ।
श्रीमांगी,

सविनय निवेदन है कि अपने विद्यालय के सभी छात्रों की हारदीक इच्छा है कि विद्यालय परिसर में हिन्दी दिवस आयोजित की जाय । हिन्दी हमारी राष्ट्रभाषा है, हिन्दी की समृद्धि में ही देश की समृद्धि निहित है।

अतः आपसे आग्रह है कि विद्यालय परिसर में हिन्दी दिवस आयोजित करने की अनुमति प्रदान करने की कृपा करें। इसके लिए आपका सदा आभारी रहेंगे।

निवेदन
छात्रगण पटना कॉलेजिएट स्कूल,
पटना
दिनांक 10.02.2019

अथवा
अपने पिताजी को एक पत्र लिखें, जिसमें गर्म कपड़े खरीदने के लिए रुपये की मांग हो।

परीक्षा भवन
……. केन्द्र
10.02.2019

पूज्य पिता जी,
सादर प्रणाम ।

आशा है आप व परिवार के अन्य सभी सदस्य सकुशल और सानन्द होंगे। इस बार मैं आपको पत्र जल्दी न भेज सका क्योंकि मेरी परीक्षा हो रही है। उसी की तैयारी में लगा रहा । इस समय यहाँ भीषण ठंड पर रही है। मेरे पास गर्म कपड़े अपर्याप्त हैं।

अतः गर्म कपड़ा खरीदने के लिए आप मुझे 500 रुपये भेज दें। मेरी ओर से पूज्यमाता जी को सादर चरण वंदना । अशोक और सीमा को प्यार । मेरे योग्य कोई सेवा हो तो अवश्य लिखें। पत्रोत्तर शीघ्र दें तथा रुपये भी जल्दी भिजवाएँ।

आपका सुपुत्र
शशांक सिन्हा

प्रश्न 4.
निम्नांकित प्रश्नों में से ‘किन्हीं पाँच के उत्तर दें। (2 x 5 = 10)

(i) भ्रष्टाचार की जड़ क्या है ? क्या आप जे0 पी0 के विचारों से सहमत हैं?
उत्तर:
भ्रष्टाचार की जड़ सरकार की गलत नीतियाँ है । इन गलत नीतियों के कारण भूख है, महँगाई है, भ्रष्टाचार हैं, कोई काम नहीं जनता का निकलता है बगैर रिश्वत दिए । सरकारी दफ्तरों में, बैंकों में, हर जगह, टिकट लेना है उसमें, जहाँ भी हो, रिश्वत के बगैर काम नहीं जनता का होता है। हर प्रकार के अन्याय के नीचे जनता दब रही है। शिक्षा-संस्थाएँ भ्रष्ट हो रही है। हमारे नौजवानों का भविष्य अंधेरे में पड़ा हुआ है । जीवन उनका नष्ट हो रहा है इस प्रकार चारो ओर भ्रष्टाचार व्याप्त है। इसे दूर करने के लिए समाजवादी तरीके से सरकार ऐसी नीतियों बनाएँ जो लोक कल्याणकारी हो।

(ii) अगर मनुष्य में वाशक्ति न होती तो क्या होता?
उत्तर:
हममें वाक्शक्ति न होती तो मनुष्य गूंगा होता, वह मूकबधिर होता। मनुष्य को सृष्टि की सबसे महत्वपूर्ण देन उसकी वाक्शक्ति है। इसी वाक्शक्ति के कारण वह समाज में वार्तालाप करता है। वह अपनी बातों को अभिव्यक्त करता है और उसकी यही अभिव्यक्त वाक्शक्ति भाषा कहलाती है। व्यक्ति समाज में रहता है। इसलिए अन्य व्यक्ति के साथ उसका पारस्परिक सम्बन्ध और कुछ जरूरतें होती हैं जिसके कारण वह वार्तालाप करता है। यह ईश्वर द्वारा दी हुई मनुष्य की अनमोल कृति है। इसी वाक्शक्ति के कारण वह मनुष्य है। यदि हममें इस वाक्शक्ति का अभाव होता तो मनुष्य जानवरों की भाँति ही होता । वह अपनी क्रियायों को अभिव्यक्त नहीं कर पाता । जो हम सुख-दुख इंद्रियों के कारण अनुभव करते हैं वह अवाक् रहने के कारण नहीं कर पाते।

(iii) लहना सिंह कौन है ?
उत्तर:
लहनासिंह एक सामान्य किसान परिवार का है । वह सिपाही की नौकरी करता है और अपने दायित्व के प्रति सजग रहता है।

(iv) मालती कौन थी?
उत्तर:
मालती रोज कहानी की एक पात्रा है। वह एक विवाहित नारी के अभावों में घुटते हुए पंगु बने व्यक्तित्व की प्रतिमूर्ति है।

(v) लहना सिंह के साथी का क्या नाम है ?
उत्तर:
लहना सिंह के साथी का नाम हजारा सिंह है।

(vi) राम का नाम सुनते ही तुलसीदास की बिगड़ी बात बन जाएगी, तुलसीदास के इस भरोसे का कारण स्पष्ट करें ?
उत्तर:
तुलसी कहते हैं कि हे प्रभु मैं अत्यन्त दीन सर्वसाधनों से हीन मनमलीन दुर्बल और पापी मनुष्य हूँ फिर भी आपका नाम लेकर अपना पेट भरता हूँ। तुलसी को यह विश्वास है कि उनके राम कृपालु हैं, दयानिधान हैं वे हर बात को अच्छी तरह समझकर उसका समाधान करते हैं यही उनके भरोसे का कारण है।

(vii) पुत्र के लिए उसकी माँ क्या-क्या करती है ?
उत्तर:
पुत्र के लिए माँ हर कदम पर सचेत होकर चलती है। उसे डर लगा रहता है कि कहीं उसे लू न लग जाए, कहीं उसे सर्दी न लग जाय, उस भय से उसे अपने गोद से भी नहीं उतारती । उसे अपने आँचल की ओट में छिपाये रहती है। जब पुत्र माँ कहकर पुकारता है तो माँ सभी काम छोड़कर दौड़ी चली आती है। पुत्र के न सोने पर उसे थपकी देती है, कभी लोरियाँ गाकर सुलाती है। उसकी आँखें अपने पुत्र के मुख पर मलिनता देखकर रात भर जाग जाती हैं। माँ पुत्र को पाने के लिए मिन्नतें माँगती हैं। कहीं दूध, बताशा, नारियल इत्यादि चढ़ावे के रूप में चढ़ाती हैं। पत्थर जैसे अमूर्त वस्तु को देवता मानकर पुत्र प्राप्ति की इच्छा के लिए मिन्नतें माँगती है। इस तरह पुत्र के लिए माँ का प्रेम असीम है।

(viii) ‘राख से लीपा हुआ चौका’ के बारे में कवि का क्या कहना है?
उत्तर:
कवि प्रातः नभ के सौन्दर्य से अभिभूत हो जाता है । उसे सुबह का आकाश मानो ‘राख से लीपा हुआ चौका’ के समान लगता है। आकाश जब सुबह में स्वच्छ रहता है तो ऐसा प्रतीत होता है मानो सारा आकाश राख से लीपे हुए गीले चौके के समान हो गया है।

(ix) ‘जन जन का चेहरा एक’ से कवि का क्या तात्पर्य है ?
उत्तर:
पीड़ितऔर संघर्षशील जनता का, जो अपने मानवोचित अधिकारों के लिए कर्मरत है। यह जनता दुनिया के तमाम देशों में संघर्षरत है और अपने कर्म और श्रम से न्याय, शांति और बंधुत्व की दिशा में प्रयासरत है। कवि इस जनता में एक अंतवर्ती एकता देखता है। इसलिए कवि ‘जन-जन का चेहरा एक’ कहता है।

(x) ‘पद्मावत’ के रचनाकार कौन हैं ?
उत्तर:
पद्मावत के रचनाकार जायसी है।

प्रश्न 5.
निम्नांकित प्रश्नों में से किन्हीं तीन के उत्तर दें : (3 x 5 = 15)

(i) विशनी केवल मानक की माँ नहीं है बल्कि हर सिपाही की माँ है, कैसे?
उत्तर:
एकांकी के दूसरे भाग में विशनी स्वप्न में जो घटना घटती है उसमें जो संवाद होता है उस संवाद से उसमें किसी भी सिपाही की माँ की हँढा तजा सकता है । जब सिपाही मानक को खदेड़ते हुए विशनी के पास ले आता है तो मानक को गले से लिपटी जाता है और सिपाही के पूछने पर कि इसकी तू क्या लगती है विशनी का जबाव आता है-मैं इसकी माँ हूँ। मैं तूझे इसे मारने नहीं दूंगी। तब सिपाही का जबाव आता है यह हजारों का दुश्मन है वे उसको खोज रहे हैं तब विशनी कहती हैं-तू भी तो आदमी है, तेरा भी घर-बार होगा। तेरी भी माँ होगी। तू माँ के दिल को नहीं समझता। मैं अपने बच्चे को अच्छी तरह से जानती हूँ। साथ ही जब मानक का पटलकर सिपाही पर होता है तब विशनी मानक को यह कहती है कि बेटा ! तू इसे नहीं मारेगा । तुझे तेरी माँ की सौगन्ध इसे नहीं मारेगा इन संवादों से पता चलता है कि विशनी मानक को जितना बचाना चाहती है उतना ही उस सिपाही को भी । उसका दिल दोनों के लिए एक है। अतः उसमें किसी भी सिपाही की माँ को ढूँढ़ा जा सकता है।

करते हैं। उनका साहित्य महज आक्रोश और प्रतिक्रिया से परे समता न्याय और मानवीयता पर टिकी नई पूर्णत्तर सामाजिक चेतना और संस्कृति बोध की आहट है। उनके लेखन में अनुभव की सच्चाई और वास्तव बोध से उपजी नवीन रचना संस्कृति की अभिव्यक्ति है । दलित जीवन के रोष और आक्रोष को वे अपने संवेदनात्मक रचनानभवों की भट्ठी में गलाकर रचना की एक नई इनारत पेश करते हैं। जिसका परिप्रेक्ष्य मानवीय है।

(iii) ओ सदानीरा’ का केन्द्रीय भाव लिखें।
उत्तर:
जगदीशचंद्र माथुर ‘ओ सदानीरा’ शीर्षक निबंध के माध्यम से गंडक नदी को निमित्त बनाकर उसके किनारे की संस्कृति और जीवन प्रवाह की अंतरंग झाँकी पेश करते हैं जो स्वयं गंडक नदी की तरह प्रवाहित दिखलाई पड़ता है। सर्वप्रथम चंपारन क्षेत्र की प्राकृतिक वातावरण का वर्णन करते हुए उसकी एक-एक अंग का मनोहारी अंकन करते है। जेसे छायवादी कविताओं में प्रकृति का मानवीकरण देखा जा सकता है उसी तरह निबंध में भी देखा जा सकता है।

एक अंश देखिए-“बिहार के उत्तर-पश्चिम कोण के चंपारण इस क्षेत्र की भूमि पुरानी भी और नवीन भी। हिमालय की तलहटी में जंगलों की गोदी से उतारकर मानव मानो शैशव-सुलभ अंगों और मुस्कान वाली धरती को ठुमक-ठुमककर चलना सिखा रहा है।” इसके साथ माथुर संस्कृति के गर्त में जाकर नदियों में बाढ़ आना उन्हें लगता है जैसे उन्मत्त यौवना वीरांगना हो जो प्रचंड नर्तन कर रही हो। उन्हें साठ-बासठ की बाढ़ रामचरितमानस के क्रोधरूपी कैकयी की तरह दिखलाई पड़ती है। वे बताते हैं नदियों में बाढ़ आना मनुष्यों के उच्छृखलता के कारण हैं। यदि महावन जो चंपारन से गंगा तट तक फैला हुआ था न कटता तो बाढ़ न आती ।

माथुर तर्क देते हैं कि वसुंधराभोगी मानव और धर्मोधमानव एक ही सिक्के के दो पहलू हैं। क्योंकि वसुंधरा भोगी मानव अपने भोग-विलास के लिए जंगलों की कटाई कर रहा है तो धर्मांध मानव पूजा-पाठ के सड़ी गली सामाग्री को गंगा नदी में प्रवाहित कर उसे दूषित कर रहा है। माथुर मध्ययुगीन समाज की सच्चाई भी बताते हैं कि आक्रमण के कारण या अपनी महत्वाकांक्षा की तृप्ति के लिए मुसलमान शासकों ने अंधाधुंध जंगलों की कटाई की । इसी तरह यहाँ अनेक संस्कृति आये और वहीं रच-बस गये। सभी ने उसका दोहन ही किया । इस मिली-जुली संस्कृति का परिणाम कीमियो प्रक्रिया है। चंपारन के प्रत्येक स्थल पर प्राचीन युग में लेकर आधुकिन युग में

है। चंपारन के प्रत्येक स्थल पर प्राचीन युग में लेकर आधुकिन युग में गाँधी के चंपारण आने तक के पूरा इतिहास को अपने लेखनी के माध्यम से अच्छे-बुरे प्रभाव को खंगालते हैं। इस परिचय के संदर्भ में कहीं भी कला संस्कृति उसकी भाषा उनकी आँखों से ओझल नहीं हो पाती। – अंत में गंडककी महिमा का बखान करते हुए कहते हैं कि ओ सदानीरा । ओ चक्रा ! ओ नारायणी । ओ महागंडक ! युगों से दीन-हीन जनता इन विविध नामों से तुझे संबोधित करती रही है। आ तेरे पूजन के लिए जिस मंदिर की प्रतिष्ठित हो रही है, उसकी नींव बहुत गाढ़ी हैं। इसे तू ठुकरा न पाएगी।

(iv) कविता की बिंब योजना’ पर टिप्पणी लिखें।
उत्तर:
कविता में शमशेर ने दो तरह के बिंब प्रस्तुत किए हैं जो एक जीवन से जुड़ती हैं जिसे मानवीय व्यापार करते हैं दूसरा प्रकृति से जुड़ता है जिसे प्राकृतिक व्यापार करते हैं। इस प्रकार दोनों को मिलाकर कवि ने प्रकृति का मानवीकरण कर दिया है। यह छायावाद की लक्षण है। शमशेर नयी कविता के कवि हैं और उनमें भी लक्षण दिखाई पड़ते हैं।

कविता का प्रथम वाक्य
प्रात नभ था बहुत नीला शंख जैसे
भोर का नभ।
प्रातः का नभ इतना नीला था कि नीला शंख लग रहा था । शंख जिप प्रकार ध्वनित होता है उसी प्रकार प्रात: में हवा चलने के कारण प्रातः भी ध्वनित होता है।

भोर का नभ-अर्थात् अब सुबह हो रही है सूर्य की लाली दिगन्त में छा गई है। प्रातः के बाद भोर शब्द का प्रयोग गाँव में दिन का शुरुआत के साथ जीवन के कार्य-व्यापार का बिंब खड़ा करता है।

राख से लीपा हआ चौका (अभी गीला पड़ा है

भोर होने के साथ ही गृहिणी पहले चौका लीपती है और उसके बाद कोई कार्य करती है। भोर का आकाश इतना नीला या स्याह है कि लगता है जैसे राख से लीप दिया गया हो । भोर का आकाश अभी गीला इसलिए है कि वह ओसपूर्ण है, उसमें आर्द्रता है।

बहुत काली सिल जरा से लाल केसर से कि जैसे घुल गई हो ।
सुबह चौका लीपने के बाद गृहिनी सिलवट पर मसाला पीसती है। . पीसने के बाद सिलवट धुल जाने पर भी थोड़ी देर के लिए केसर की लालिमा बनी रहती है। उसी प्रकार सूर्योदय होने के पूर्व भी इसी प्रकार आकाश लगता है।

स्लेट पर या लाल खड़िया चाक मल दी हो किसी ने ।
जब सब काम से गृहिणी निवृत्त हो लेती है तब उसका ध्यान बच्चों पर जाता है और बच्चों को वह स्लेट लेकर पढ़ने बैठाती है। बच्चे स्लेट पर खड़िया से लिखने के साथ खूब रगड़ भी देते हैं। प्रकृति के संदर्भ में विंब यह है कि सूर्य की लाली इस प्रकार छा गई है जैसे लाल खड़िया किसी ने मल दी हो।

नील जल में या किसी की गौर
झिलमिल देह जैसे हिल रही हो।
गृहिणी स्नान करती है तब उर्मिला लहरें गौर वर्ण से संयोग कर झिलमिलाती प्रतीत होती हैं। इसी प्रकार सूर्योदय होने पर जल में किरणें पड़ती हैं तो वह झिलमिलाता प्रतीत होता है।

(v) सुभद्रा कुमारी चौहान का जन्म कब और कहाँ हुआ था ?
उत्तर:
सुभद्रा कुमारी चौहान का जन्म सन् 16 अगस्त 1904 ई. को प्रयाग के निहालपुर मुहल्ले में हुआ था। उनका विद्यार्थी जीवन प्रयाग में ही बीता । कास्थवेट गर्ल्स कॉलेज से आपने शिक्षा प्राप्त करने के बाद नवलपुर के सुप्रसिद्ध वकील डॉ. लक्ष्मण सिंह के साथ आपका विवाह हो गया । आपकी रुचि साहित्य में बाल्यकाल से ही थी। प्रथम काव्य रचना

आपने 15 वर्ष की आयु में ही लिखीं थी। राष्ट्रीय आन्दोलन में बराबर सक्रिय भाग लेती रहीं। कई बार जेल गयी। काफी दिनों तक मध्यप्रांत असेम्बली की कांग्रेस सदस्या रहीं और साहित्य एवं राजनीतिक जीवन में समान रूप से भाग लेकर अन्त तक देश की एक जागरूक नारी के रूप में अपना कर्तव्य निभाती रहीं। 1948 ई. में अप्रैल में आपका स्वर्गवास हो गया।

(vi) ‘उषा’ कविता का केन्द्रीय भाव लिखें।
उत्तर:
उषा’ हिन्दी साहित्य के नयी कविता के कवि शमशेर बहादुर सिंह द्वारा रचित प्राकृतिक सौन्दर्यपरक कविता है । इस कविता में कवि ने सूर्यादय के पूर्व के उषाकालीन आकाशीय स्वरूप और सौन्दर्य का मोहक चित्रण किया है। कवि ने इसके चित्रण में भिन्न-भिन्न उपमानों की सहायता भी ली है।

सूर्योदय के पूर्व का काल उषाकाल कहलाता है । उस समय आकाश बिल्कुल नीला और स्वच्छ रहता है। उसकी नीलिमा के बीच आनेवाला उजाला हल्के रूप में झाँकता-सा नजर आता है । प्रातः काल की उस वेला में आकाश नीले राख-सा लगता है। हल्के अंधकार के आवरण में बँके रहने के कारण संपूर्ण आकाश राख से लीपे हुए गीले चौक के समान लगता है।

फिर, धीरे-धीरे सूर्य की हल्की लालिमा की झलक उभरने लगती है। तब उसका स्वरूप कुछ बदल-सा जाता है और उस समय आकाश को देखकर ऐसा लगता है कि आकाश वह काली सिल हो जो जरा-सा लाल केसर से धुली हुई हो या वैसा स्लेट ही जिसपर खड़ियां चाक मल दी गई हो । अंत में कवि ने उषाकालीन आकाश के प्राकृतिक सौन्दर्य को प्रभावपूर्ण रूप से प्रस्तुत करने के लिए अंतिम उपमान लगाकर चर्चा करते हुए कहा है कि उस समय आकाश के वक्ष पर उषा कालीन दृश्य ऐसा लगता है मानो नीले जल में झिलमिलाती गोरी कोई काया खड़ी हो ।

इसी परिवेश में सूर्योदय होता है। फिर सूर्य की किरणें विकीर्ण होने लगती हैं और आकाश की गोद में चल रहा उषा का यह जादू और उसका नजारा सब समाप्त हो जाता है।

प्रश्न 6.
संक्षेपण करें: (1 x 4 = 4)

दूसरों की निन्दा करने का एक प्रमुख कारण दूसरे के प्रति ईर्ष्या-द्वेष भी होता है। कुछ लोग ईर्ष्या-द्वेष से दूसरों की निंदा करते हैं । इस प्रकर की निंदा सरस होती है। उसमें आनंद नहीं आता । निंदा करने का जो आनंद समर्पित भाव से निंदा करने में आता है, वह ईर्ष्या-द्वेष रखकर निंदा करने में नहीं आता है। निन्दा करने वाला सदा दुखी और अशान्त रहता है। उससे दूसरों की उन्नति, प्रगति सुख, समृद्धि सहन नहीं होती । अपनी असमर्थता और हीनता के कारण उसमें ईर्ष्या-द्वेष उत्पन्न होता है। दूसरों की निन्दा करने पर उसे थोड़ी-सी शान्ति मिलती है। ऐसा निन्दक दया का पात्र होता है।
उत्तर:
शीर्षक-निन्दा ईर्ष्या-द्वेष से प्रेरित होकर दूसरी की निन्दा करते हैं जो सरल नहीं होती है। लेकिन समर्पित भाव से निन्दा करने में आनन्द आता है। निन्दक सदा दुःखी और अशांत रहता है। उससे दूसरे की अच्छाई सहन नहीं होती है।

Bihar Board 12th Physics Objective Questions and Answers

Bihar Board 12th Physics Objective Answers Chapter 12 Atoms

Question 1.
In Geiger-Marsden scattering experiment, the trajectory traced by an a-particle depends on
(a) number of collision
(b) number of scattered a-particles
(c) impact parameter
(d) none of these
Answer:
(c) impact parameter

Question 2.
In the Geiger-Marsden scattering experiment, in case of head-on collision the impact parameter should be
(a) maximum
(b) minimum
(c) infinite
(d) zero
Answer:
(b) minimum

Question 3.
Rutherford’s experiments suggested that the size of the nucleus is about
(a) 10^-14 m to 10^-12 m
(b) 10^-15 m to 10^-13 m
(c) 10^-15 m to 10^-14 m
(d) 10^-15 m to 10^-12 m
Answer:
(c) 10^-15 m to 10^-14 m

Question 4.
In an atom the ratio of radius of orbit of electron to the radius of nucleus is
(a) 10³
(b) 10⁴
(c) 10⁵
(d) 10⁶
Answer:
(c) 10⁵

Question 5.
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about
(a) 10¹
(b) 10⁵
(c) 10¹⁰
(d) 10¹⁵
Answer:
(d) 10¹⁵

Question 6.
The first spectral series was discovered by
(a) Balmer
(b) Lyman
(c) Paschen
(d) Pfund
Answer:
(a) Balmer

Question 7.
Which of the following spectral series falls within the visible range of electromagnetic radiation?
(a) Lyman series
(b) Balmer series
(c) Paschen series
(d) Pfund series
Answer:
(b) Balmer series

Question 8.
The shortest wavelength present in the Paschen series of spectral lines is
(a) 720 nm
(b) 790 nm
(c) 800 nm
(d) 820 nm
Answer:
(d) 820 nm

Question 9.
The shortest wavelength in the Balmer series is (R = 1.097 x 10⁷ m^-1)
(a) 200 nm
(b) 256.8 nm
(c) 300 nm
(d) 364.6 nm
Answer:
(d) 364.6 nm

Question 10.
The wavelength limit present in the Pfund series is (R = 1.097 x 10⁷ m s^-1)
(a) 1572 nm
(b) 1898 nm
(c) 2278 nm
(d) 2535 nm
Answer:
(c) 2278 nm

Question 11.
When an electron jumps from the fourth orbit to the second orbit, one gets the
(a) second line of Paschen series
(b) second line of Balmer series
(c) first line of Pfund series
(d) second line of Lyman series
Answer:
(b) second line of Balmer series

Question 12.
When an atomic gas or vapour is excited at low pressure, by passing an electric current through it then
(a) emission spectrum is observed
(b) absorption spectrum is observed
(c) band spectrum is observed
(d) both (b) and (c)
Answer:
(a) emission spectrum is observed

Question 13.
In Balmer series of emission spectrum of hydrogen, first four lines with different wavelength Ha, Hp, Hy and H5 are obtained. Which line has maxium frequency out of these?
(a) Hα
(b) Hβ
(c) Hγ
(d) Hδ
Answer:
(d) Hδ

Question 14.
Hydrogen atom emits light when it changes from n = 5 energy level to n =2 energy level. Which colour of light would the atom emit?
(a) red
(b) yellow
(c) green
(d) violet
Answer:
(d) violet

Question 15.
The wavelength of the first line of Lyman series is 1215 kA, the wavelength of first line of Balmer series will be
(a) 4545 A
(b) 5295 A
(c) 6561 A
(d) 6750 A
Answer:
(c) 6561 A

Question 16.
According to Bohr’s theory, the wave number of last line of Balmer series is (R = 1.1 x 10⁷ m^-1)
(a) 5.5 x 10⁵ m^-1
(b) 4.4 x 10⁷ m^-1
(c) 2.75 x 10⁶ m^-1
(d) 2.75 x 10⁸ m^-1
Answer:
(c) 2.75 x 10⁶ m^-1

Question 17.
What is the ratio of the shortest wavelength of the Balmer series to the shortest wavelength of the Lyman series?
(a) 4 : 1
(b) 4 : 3
(c) 4 : 9
(d) 5 : 9
Answer:
(a) 4 : 1

Question 18.
The Bohr model of atoms
(a) assumes that the angular momentum of electrons is quantized.
(b) uses Einstein’s photoelectric equation.
(c) predicts continuous emission spectra for atoms.
(d) predicts the same emission spectra for all types of atoms.
Answer:
(a) assumes that the angular momentum of electrons is quantized.

Question 19.
The angular speed of the electron in the n^th orbit of Bohr’s hydrogen atom is
(a) directly proportional to n
(b) inversely proportional to \(\sqrt{n}\)
(c) inversely proportional to n²
(d) inversely proportional to. n³
Answer:
(d) inversely proportional to. n³

Question 20.
The moment of momentum for an electron in second orbit of hydrogen atom as per Bohr’s model is
\((a) \frac{h}{\pi}
(b) 2 \pi h
(c) \frac{2 h}{\pi}
(d) \frac{\pi}{h}\)
Answer:
\((a) \frac{h}{\pi}\)

Question 21.
According to second postulate of Bohr model, the angular momentum (L_n) of n^th possible orbit of hydrogen atom is given by
Answer:
(b)

Question 22.
The total energy (E_n) of the electron in the stationary states in the nth orbit of the hydrogen atom is

Answer:
(b)

Question 23.
The radius of nth orbit rn in terms of Bohr radius (a0) for a hydrogen atom is given by the relation
\((a) n a_{0}
(b) \sqrt{n} a_{0}
(c) n^{2} a_{0}
(d) n^{3} a_{0}\)
Answer:
\((c) n^{2} a_{0}\)

Question 24.
In the Bohr model of the hydrogen atom, the lowest orbit corresponds to
(a) infinite energy
(b) maximum energy
(c) minimum energy
(d) zero energy
Answer:
(c) minimum energy

Question 25.
The value of ionisation energy of the hydrogen atom is
(a) 3.4 eV
(b) 10.4eV
(c) 12.09 eV
(d) 13.6 eV
Answer:
(d) 13.6 eV

Question 26.
Energy is absorbed in the hydrogen atom giving absorption spectra when transition takes place from
(a) n = 1 → n’ where n >1
(b) n = 2 → 1
(c) n → n
(d) n → n’ = ∞
Answer:
(a) n = 1 → n’ where n >1

Question 27.
In which of the following systems will the radius of the first orbit (n –1) be minimum?
(a) doubly ionized lithium
(b) singly ionized helium
(c) deuterium atom
(d) hydrogen atom
Answer:
(a) doubly ionized lithium

Question 28.
When an electron falls from a higher energy to a lower energy level the difference in the energies appears in the form of
(a) electromagnetic radiation only
(b) thermal radiation only
(c) both electromagnetic and thermal radiations
(d) none of these
Answer:
(a) electromagnetic radiation only

Question 29.
From quantisation of angular momentum, one gets for hydrogen atom, the raius of the nth orbit as
\(r_{n}=\left(\frac{n^{2}}{m_{e}}\right)\left(\frac{h}{2 \pi}\right)^{2}\left(\frac{4 \pi^{2} \varepsilon_{0}}{e^{2}}\right)\)
For a hydrogen like atom of atomic number Z,
(a) the radius of the first orbit will be same
(b) r_n will be greater for larger Z values
(c) r_n will be smaller for larger Z values
(d) none of these
Answer:
(c) r_n will be smaller for larger Z values

Question 30.
If E is the energy of n^th orbit of hydrogen atom the energy of n^th orbit of He atom will be
(a) E
(b) 2E
(c) 3E
(d) 4E
Answer:
(d) 4E

Question 31.
In which of the following Bohr’s orbit (n) a hydrogen atom emits the photons of lowest frequency?
(a) n = 2 to n = 1
(b) n = 4 to n = 2
(c) n = 4 to n = 1
(d) n = 4 to n = 3
Answer:
(d) n = 4 to n = 3

Question 32.
If an electron is revolving in its Bohr orbit having Bohr radius of 0.529 A, then the radius of third orbit is
(a) 4234 nm
(b) 4496 A
(c) 4.761 A
(d) 5125nm
Answer:
(c) 4.761 A

Question 33.
The energy required to excite an electron in hydrogen atom to its first excited state is
(a) 8.5eV
(b) 10.2eV
(c) 12.7eV
(d) 13.6eV
Answer:
(b) 10.2eV

Question 34.
A triply ionized beryllium (Be³⁺) has the same orbital radius as the ground state of hydrogen. Then the quantum state n of Be³⁺ is
(a) n = 1
(b) n = 2
(c) n = 3
(d) n = 4
Answer:
(b) n = 2

Question 35.
The ground state energy of hydrogen atom is -13.6 e V. The kinetic of the electron in this state is
(a) 2.18 x I0^-14 J
(b) 2.18 x 10^-16 J
(c) 2.18 x 10^-18 J
(d) 2.18 x 10^-19 J
Answer:
(c) 2.18 x 10^-18 J

Question 36.
If the radius of inner most electronic orbit of a hydrogen atom is 5.3 x 10-11 m, then the radii of n = 2 orbit is
(a) 1.12 A
(b) 2.12 A
(c) 3.22 A
(d) 4.54 A
Answer:
(b) 2.12 A

Question 37.
A hydrogen atom initially in the ground level absorbs a photon and is excitied to n = 4 level then the wavelength of photon is
(a) 790 A
(b) 870 A
(c) 970A
(d) 1070 A
Answer:
(b) 870 A

Question 38.
If speed of electron in ground state energy level is 2.2 x 10⁶ m s^-1, then its speed in fourth excited state will be
(a) 6.8 x 10⁶ m s^-1
(b) 8.8 x 10⁶ m s^-1
(c) 5.5 x 10⁵ m s^-1
(d) 5.5 x 10⁶ m s^-1
Answer:
(c) 5.5 x 10⁵ m s^-1

Question 39.
An electron is revolving in the /Ith orbit of radius 4.2 A, then the value of n is (r₁ = 0.529 A)
(a) 4
(b) 5
(c) 6
(d) 3
Answer:
(d) 3

Question 40.
The ratio of the speed of the electron in the ground state of hydrogen atom to the speed of light in vacuum is
\((a) \frac{1}{2}
(b) \frac{2}{237}
(c) \frac{1}{137}
(d) \frac{1}{237}\)
Answer:
\((c) \frac{1}{137}\)

Question 41.
The binding energy of an electron in the ground state of He is equal to 24.6 eV. The energy required to remove both the electrons is
(a) 49.2 eV
(b) 54.4eV
(c) 79eV
(d) 108.8 eV
Answer:
(c) 79eV

Question 42.
The ionization energy of Li⁺⁺ is equal to
(a) 9 hcR
(b) 6 hcR
(c) 2 hcR
(d) hcR
Answer:
(a) 9 hcR

Question 43.
The de-Broglie wavelength of an electron in the first Bohr orbit is
(a) equal to one-fourth the circumference of the first orbit
(b) equal to half the circumference of first orbit
(c) equal to twice the circumference of first orbit
(d) equal to the circumference of the first orbit
Answer:
(d) equal to the circumference of the first orbit

Question 44.
The excitation energy of Lyman last line is
(a) the same as ionisation energy
(b) the same as the last absorption line in Lyman series
(c) both (a) and (b)
(d) different from (a) and (b)
Answer:
(c) both (a) and (b)

Question 45.
The number of de Broglie wavelengths contained in the second Bohr orbit of Hydrgen atom is
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2

Question 46.
If there are N atoms in a source of Laser light and each atom is emitting light with intensity I, then the total intensity produced by it is
(a) NI
(b) N²I
(C) N³I
(d) N⁴I
Answer:
(b) N²I

Question 47.
The acronym LASER stands for
(a) Light Amplification by Stimulated Emission of Radiation
(b) Light Amplitude by Stimulated Emission of Radiation
(c) Light Amplification by Strong Emission of Radiation
(d) Light Amplification by Stimulated Emission of Radiowave
Answer:
(a) Light Amplification by Stimulated Emission of Radiation

Question 48.
Two H atoms in the ground state collide inelastically. The maximum amount by which their combined kinetic energy is reduced is
(a) 10.2 eV
(b) 20.4eV
(c) 13.6eV
(d) 27.2eV
Answer:
(a) 10.2 eV

Hints & Explanations

Question 4.
(c) The radius of orbit of electrons = 10^-10 m radius of nucleus = 10^-15 m
Ratio = \(=\frac{10^{-10}}{10^{-15}}=10^{5}\)
Hence the radius of electron orbit is 105 times larger than the radius of nucleus.

Question 5.

Question 8.
(d) The wavelength for Paschen series,

Question 9.
(d) Wavelength for Balmer series is \(\frac{1}{\lambda}=R\left(\frac{1}{2^{2}}-\frac{1} at n = ∞, the limit of the series observed.

Question 10.
(c) The wavelength for Pfund series is given by

Question 15.
(c) Here, λ_L. = 1215 A, For the first line of Lyman series.

Question 20.
(a) According to Bohr’s second postulate Angular momentum, [latex]L=\frac{n h}{2 \pi}\)

Angular momentum is also called a moment of momentum.

For second orbit, n = 2 \(L=\frac{2 h}{2 \pi}=\frac{h}{\pi}\)

Question 23.
(c) The radius of n^th orbit r_n = n² \(\frac{\hbar^{2} 4 \pi \varepsilon_{0}}{m e^{2}}\) where \(\frac{\hbar^{2} 4 \pi \varepsilon_{0}}{m e^{2}}=a_{0}[/ltaex] (Bohr radius)
Hence, r_n = n² a_0.

Question 30.
(d) Since Bohr’s formula for energy in n^th orbit is

Question 31.
(d) The energy level diagram schematically looks like this. As we move to higher and higher levels, the energy increases, but the energy gap between any two levels decreases. Hence in the transition from n = 4 to n = 3, energy released will be E₄ – E₃.

And in the transition from n = 2 to n – 1, energy released is E₂ -E₁.
Now as E₄ – E₃ < E₂ – E₁

[latex]\Rightarrow h v_{43}<h v_{21} \Rightarrow h v_{43}<h v_{21}\)

Question 32.
(c) As r_n = n² a₀
Here, a₀ = 0.529 A and n = 3
.-. r_n=3 = (3)³ a₀ = 9 x 0.529A = 4.76lA

Question 33.
(b) Energy, \(E_{n}=-\frac{13.6}{n^{2}} \mathrm{eV}\)

Question 34.
(b) Radius of nlh orbit in hydrogen like atom is
\(r_{n}=\frac{a_{0} n^{2}}{Z}\)

where a₀ is the Bohr’s radius For hydrogen atom, Z= 1
∴ r₁ = a₀ (∵ n = 1 for ground state) 2
For \(\mathrm{Be}^{3+}, \mathrm{Z}=4 ∴ r_{n}=\frac{a_{0} n^{2}}{4}\)
According to given problem \(r_{1}=r_{n} \Rightarrow a_{0}=\frac{n^{2} a_{0}}{4}\)
⇒ n = 2

Question 35.
(c) Here the ground state energy, (E) = – 13.6 eV
Since, K.E. of the electron = -E = 13.6 eV
= 13.6 x 1.6 x 10^-19 J
= 21.76 x 10^-19 J
= 2.18 x 10^-18 J.

Question 36.

Question 37.
(c) Here, = 1, and n₂ = 4
Energy of photon absorbed, E = E₂ – E₁

Question 38.
(c) According to Bohr’s model \(v=\frac{2 \mathrm{Ke}^{2} \mathrm{Z}}{n h} \text { or } v \propto \frac{1}{n}\)

Question 39.

Question 40.
(c) Speed of the electron in the ground state of hydrogen atom is
\(v=\frac{2 \pi e^{2}}{4 \pi \varepsilon_{0} h}=\frac{c}{137}=c \alpha\)

where, c = speed of light in vacuum, \(\alpha=\frac{e^{2}}{2 \varepsilon_{0} h c}\) the fine structure constant. It is a pure number whose value is \(\frac{1}{137}\).

∴ \(\frac{v}{c}=\frac{1}{137}\)

Question 41.
(c) The energy needed to remove one electron from the ground state of He = 24.6 eV.
As the He+ is now hydrogen-like, ionisation energy
\(=|-13.6| \frac{2^{2}}{1^{2}} \mathrm{eV} \Rightarrow \mathrm{E}=54.4 \mathrm{eV}\)

∴ To remove both the electrons, energy needed = (54.4 + 24.6) eV = 79. eV

Question 48.
(a) In inelastic collision kinetic energy is not conserved so some part of K.E. is lost.

∴ Reduction in K.E. = K.E. before collision – K.E. after collision
Now, since initial K.E. of each of two hydrogen atoms in ground state = 13.6 eV
Total K.E. of both Hydrogen atom before collision = 2x 13.6 = 27.2 eV
If one H atom goes over to first excited state (n₁ = 2) and other remains in ground state (n₂ = 1) then their combined K.E. after collision is
\(=\frac{13.6}{(2)^{2}}+\frac{13.6}{(1)^{2}}=3.4+13.6=17 \mathrm{eV}\)
Hence reduction in K.E. = 27.2 – 17 = 10.2 eVA

Bihar Board 12th Chemistry Objective Questions and Answers

Bihar Board 12th Chemistry Objective Answers Chapter 6 General Principles and Processes of Isolation of Elements

Question 1.
Which of the following example is not correctly matched ?
(a) Two most abudant elements-Fe, Al
(b) Two metals which occur in native state-Au, Pt
(c) Two metals which can occur in combined and native state both-Zn,Fe.
(d) None of these
Answer:
(c) Two metals which can occur in combined and native state both-Zn,Fe.

Question 2.
Which of the following is not the correct name of the formula of the ore given with it ?
(a) MgSO₄.7H₂O – Epsom salt
(b) CuCO₃.Cu(OH)₂ – Malachite
(c) KAlSi₃O₈-Feldspar
(d) MgCl₂.6H₂O – Dolomite
Answer:
(d) MgCl₂.6H₂O – Dolomite

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

Question 4.
Pyrolusite is …..
(a) a suiphide ore of Mn
(b) an oxide ore of Mn
(c) a carbide ore of P
(d) a chloride ore of Zn
Answer:
(d) a chloride ore of Zn

Question 5.
The name of the metal which is extracted from the ore is given below. Mark the example which is not correct.
(a) Malachite – Cu
(b) Calamine – Zn
(c) Chromite – Cr
(d) Dolomite – Al
Answer:
(d) Dolomite – Al

Question 6.
Which of the followings is magnetite ?
(a) Fe₂CO₃
(b) Fe₂O₃
(c) Fe₃O₄
(d) Fe₂O₃.3H₂O
Answer:
(c) Fe₃O₄

Question 7.
Which of the following is not an ore of magnesium ?
(a) Camallite
(b) Magnesite
(c) Dolomite
(d) Gypsum
Answer:
(d) Gypsum

Question 8.
Which of the following is not an oxide ore ?
(a) Corundum
(b) Zincite
(c) Calamine
(d) Chromite
Answer:
(c) Calamine

Question 9.
Which one of the following is not a sulphide ore ?
(a) Galena
(b) Iron pyrites
(c) Magnetite
(d) Copper glance
Answer:
(c) Magnetite

Question 10.
Which of the following is a halide ore ?
(a) Cassiterite
(b) Anglesite
(c) Siderite
(d) Camallite
Answer:
(d) Camallite

Question 11.
Which of the following is not a carbonate ore ?
(a) Dolomite
(b) Calamine
(c) Siderite
(d) Zincite
Answer:
(d) Zincite

Question 12.
Find the incorrect match.
(a) Kaolinite – [Al₂(OH)₄ Si₂O₅]
(b) Siderite – Fe₂O₃
(c) Sphalerite – Zns
(d) Magnetite – Fe₃O₄
Answer:
(b) Siderite – Fe₂O₃

Question 13.
Which of the following ores cannot be concentrated by magnetic spearation ?
(a) Haematite
(b) Malachite
(c) Magnetite
(d) Siderite
Answer:
(b) Malachite

Question 14.
An ore of tin containing, FeCr0₄ is concentrated by
(a) gravity separation
(b) magnetic separation
(c) froth floatation
(d) leaching
Answer:
(b) magnetic separation

Question 15.
Sulphide ore of zinc/copper is concentrated by
(a) floatation process
(b) electromagnetic proess
(c) gravity separation
(d) distillation
Answer:
(a) floatation process

Question 16.
For which of the following ores froth floatation method is used for concentration ?
(a) Haematite
(b) Zinc blende
(c) Magnetite
(d) Camallite
Answer:
(b) Zinc blende

Question 17.
The oil used as frothing agent in froth floatation process is ………….
(a) coconut oil
(b) castor oil
(c) palmitic oil
(d) pine oil
Answer:
(d) pine oil

Question 18.
How do we separate two sulphide ores by froth floatation method ?
(a) By using excess of pine oil
(b) By adjusting proportion of oil to water or using depressant
(c) By using collectors and froth stabilisers like xanthates
(d) By using some solvent in which one of the sulphides is soluble
Answer:
(b) By adjusting proportion of oil to water or using depressant

Question 19.
Common impurities present in bauxite are
(a) CuO
(b) ZnO
(c) CaO
(d) SrO₂
Answer:
(d) SrO₂

Question 20.
Which of the following reactions does not take place during leaching for concentration of bauxite ?
(a) Al₂O₃ + 2NaOH + 3H₂O → 2Na[Al(OH)₄]
(b) 2Na[Al(OH)₄]+CO₂ → Al₂O₃.xH₂O + 2NaHCO₃

Answer:
(c) Al₂O₃.2H₂O → Al₂O₃ + 2H₂O

Question 21.
The significance of leaching in the extraction of aluminium is
(a) it helps removing the impurities like SiO₂, Fe₂O₃, etc from the bauxite ore
(b) it converts the ore into oxide
(c) it reduces melthing point of the ore
(d) it eliminates water from bauxite
Answer:
(a) it helps removing the impurities like SiO₂, Fe₂O₃, etc from the bauxite ore

Question 22.
Which of the following metals is not extracted by leaching ?
(a) Aluminium
(b) Mercury
(c) Silver
(d) Gold
Answer:
(b) Mercury

Question 23.
Heating pyrites to remove sulphur is called ……………….
(a) smelting
(b) calcination
(c) liquation
(d) roasting
Answer:
(d) roasting

Question 24.
Which of the following is not an example of roasting ?
(a) 2ZnS + 3O₂ → 2ZnO + 2SO₂
(b) 2PbS + 3O₂ → 2PbO + 2SO₂
(c) 2Cu → S + 3O₂ → 2Cu₂O + 2SO₂
(d) 2Cu₂O + Cu₂S → 6Cu + SO₂
Answer:
(d) 2Cu₂O + Cu₂S → 6Cu + SO₂

Question 25.
Which of the following metals is extracted using a silica lined convertor ?
(a) Mg
(b) Al
(c) Cu
(d) Zn
Answer:
(c) Cu

Question 26.
Which of the following reactions show the process of smelting ?
(a) 2PbO + PbS → 3Pb + SO₂
(b) 2Na[Au(CN)₂] + Zn → Na₂[Zn(CN)₄] + 2Au
(c) PbO + CPb + CO
(d) 2HgS + 3O₂ → 2HgO + 2SO₂
Answer:
(c) PbO + CPb + CO

Question 27.
Which of the following sulphides when heated strongly in air gives the corresponding metal without undergoing separate reduction of oxide ?
(a) Cu₂S
(b) FeS
(c) HgS
(d)ZnS
Answer:
(c) HgS

Question 28.
Ellingham diagram represents change of
(a) ΔG With temperature
(b) ΔH with temperature
(c) ΔG with pressure
(d) (ΔG -TΔS) with temperature
Answer:
(a) ΔG With temperature

Question 29.
Which of the following reactions takes place at higher temperature range (900 K-1500 K) in blast furnace ?
(a) 3Fe₂O₃ + PCO → 2Fe₃+CO₂
(b) FeO + CO → Fe + CO₂
(c) Fe₃O₄ +4CO → 3Fe + 4CO₂
(d) Fe₂O₃ + CO → 2FeO + CO₂
Answer:
(a) 3Fe₂O₃ + PCO → 2Fe₃+CO₂

Question 30.
During the extraction of heematite, limestone is added which acts as
(a) flux
(b) slag
(c) reducing agent
(d) gangue
Answer:
(a) flux

Question 31.
Which of the following stage is produced during extraction of iron ?
(a) CaSiO₃
(b) FeSiO₃
(c) MgSiO₃
(d)ZnSiO₃
Answer:
(a) CaSiO₃

Question 32.
Wrought iron is manufactured from cast iron by heathing it with
(a) C
(b) CaCO₃
(c) Fe₂O₃
(d) SiO₂
Answer:
(c) Fe₂O₃

Question 33.
In blast furnace iron oxide is reduced by
(a) silica
(b) carbon monoxide
(c) carbon
(d) lime stone
Answer:
(b) carbon monoxide

Question 34.
Blister copper is …………..
(a) impure copper
(b) obtained in self-reduction process during bessemerisation
(c) Both are correct
(d) None is correct
Answer:
(c) Both are correct

Question 35.
From the Ellingham graph between Gibb’s energy and temperature, out of C and CO which is a better reducing agent for ZnO ?
(a) Carbon
(b) CO
(c) Both of these
(d) None of these
Answer:
(a) Carbon

Question 36.
In a thermite process………. is used as reducing agent.
(a) Zn
(b) Al
(c) Mn
(d) Fe
Answer:
(b) Al

Question 37.
In metallurgical process, aluminium acts as …………………
(a) an oxidising agent
(b) basic flux
(c) acidic flux
(d) basic flux
Answer:
(b) basic flux

Question 38.
Which of the following metals cannot be obtained by reduction of its metal oxide by aluminium ?
(a) Cr
(b) Mn
(c) Fe                   ’
(d) Mg
Answer:
(d) Mg

Question 39.
Which of the following metals is obtained by electrolytic reduction process ?
(a) Fe
(b) Cu
(c) Ag
(d) Al
Answer:
(d) Al

Question 40.
Cryolite and fluorspar are mixed with Al₂O₃ during ‘ electrolysis for extraction of aluminium to
(a) increases the mass of the reaction mixture
(b) get other products at anode like fluorine
(c) lower the melting point and increase the conductivity of the electrolyte
(d) reduce aluminium oxide by cryolite
Answer:
(c) lower the melting point and increase the conductivity of the electrolyte

Question 41.
Which of the following metals cannot be obtained by electrolysis ?
(a) Cr
(b) Na
(c) Ca
(d) Mg
Answer:
(a) Cr

Question 42.
Extraction of chlorine from brine is based on
(a) reduction
(b) displacement
(c) oxidation
(d) evaporation
Answer:
(c) oxidation

Question 43.
…. being highly reactive is used in the extraction of chromium and manganese.
(a) Al
(b) Zn
(c) Cu
(d) Mg
Answer:
(a) Al

Question 44.
Which of the following is not a method of refining of metals ?
(a) Electrolysis
(b) Semlting
(c) Poling
(d) Liquation
Answer:
(b) Semlting

Question 45.
Most electropositive metals are obtained from their ores by ………….
(a) autoreduction
(b) smelting with carbon
(c) electrolysis of fused salts
(d) thermal decomposition
Answer:
(c) electrolysis of fused salts

Question 46.
Which one of the following is true in electrolytic refining ?
(a) Impure metal is made cathode
(b) Impure metal is made anode
(c) Impure metal is made cathode and pure metal as anode
(d) Both electrodes must be of pure metal
Answer:
(b) Impure metal is made anode

Question 47.
Carnallite on electrolysis gives ………..
(a) Mg and CI₂
(b) Ca and Cl₂
(c) K and Cl₂
(d) Al and Cl₂
Answer:
(c) K and Cl₂

Question 48.
In electro-refining of copper, some gold is deposited as
(a) cathode mud
(b) electrolyte
(c) anode mud
(d) cathode
Answer:
(c) anode mud

Question 49.
During the process of electrolytic refining of copper, some metals present as impurity settle as ‘anode mud’. These are
(a) Sn and Ag
(b) Pb and Zn
(c) Ag and Au
(d) Fe and Ni
Answer:
(c) Ag and Au

Question 50.
Which of the following is used as a method of purification for silicon ?
(a) Electrolytic refining
(b) Liquation
(c) Zone refining
(d) Distillation
Answer:
(c) Zone refining

Question 51.
Impure

The above process of purification of the metal is known as
(a) van Arkel process
(b) pyrometallurgy
(c) Mond process
(d) zone refining
Answer:
(b) pyrometallurgy

Question 52.
Which process of purification is represented by the following reaction

(a) Zone refining
(b) Mond’s process
(c) Cupellation
(d) van Arkal process
Answer:
(c) Cupellation

Question 53.
Chromatography is a useful method for purification of elements which are
(a) very reactive
(b) available in minute quantities
(c) present in abundance
(d) highly electropositve
Answer:
(b) available in minute quantities

Question 54.
A number of elements are available in earth’s crust but most abundant elements are……………..
(a) Al and Fe
(b) Al and Cu
(c) Fe and Cu
(d) Cu and Ag
Answer:
(a) Al and Fe

Question 55.
In the extraction of copper from its sulphide ore, the mental is formed by the reduction of Cu₂O with………………….
(a)FeS
(b)CO
(c) Cu₂S
(d) SO₂
Answer:
(c) Cu₂S

Question 56.
Electrolytic refining is used to purify which of the following metals ?
(a) Cu and Zn
(b) Ge and Si
(c) Zr and Ti
(d) Zn and Hg
Answer:
(a) Cu and Zn

Question 57.
Below point ‘A’ FeO can_________
(a) be reduced by carbon monoxide only
(b) be redued by both carbon monoxide and carbon
(c) be reduced by carbon only
(d) not be reduced by both carbon and carbon monoxide
Answer:
(a) be reduced by carbon monoxide only

Bihar Board 12th Biology Objective Questions and Answers

Bihar Board 12th Biology Objective Answers Chapter 10 Microbes in Human Welfare

Question 1.
Microbes are present in
(a) soil
(b) thermal vents
(c) polluted water
(d) all of these
Answer:
(d) all of these

Question 2.
Which of the following microbes is a proteinacious infectious agent ?
(a) Fungi
(b) Prions
(c) Bacteria
(d) Protozoa
Answer:
(b) Prions

Question 3.
The nutritive medium for growing bacteria and many fungi in laboratory is called
(a) growth media
(b) suspension media
(c) culture media
(d) colonial media
Answer:
(c) culture media

Question 4.
The inoculum is added to the fresh milk in order to convert milk into curd, the term ‘inoculum’ here refers to
(a) a starter rich in vitami Bp
(b) a starter rich in proteins
(c) a starter containing milions of LAB
(d) an aerobic digester
Answer:
(c) a starter containing milions of LAB

Question 5.
Which of the following organisms is used in the production of beverages ?
(a) Penicillium notatum
(b) Saccharomyces cerevisiae
(c) Aspergilus niger
(d) Clostridium butylicum
Answer:
(b) Saccharomyces cerevisiae

Question 6.
Which of the following options contains the end products formed during anaerobic respiration in yeast ?
(a) H₂O, CO₂ and energy
(b) H₂S, C₆H₁₂O₆ and energy
(c) CO₂, C₂H₅OH and energy
(d) H₂O and CO₂
Answer:
(c) CO₂, C₂H₅OH and energy

Question 7.
The chemical substances produced by some microbes which can kill or retard the growth of other microbes are called
(a) antiseptics
(b) antacids
(c) antibiotics
(d) all of these
Answer:
(c) antibiotics

Question 8.
Antibiotics are obtained from
(a) bacteria
(b) fungi
(c) actinomycetes
(d) all of these
Answer:
(d) all of these

Question 9.
Which of the following antibiotics was extensively used to treat American soldiers wounded in World War 11 ?
(a) Neomycin
(b) Bacitracin
(c) Chloramphenicol
(d) Penicillin
Answer:
(d) Penicillin

Question 10.
Streptomycin is obtained from
(a) Streptomyces griseus
(b) S. cerevisiae
(c) S. venezuelae
(d) S. rimosus
Answer:
(a) Streptomyces griseus

Question 11.
Enzyme which has the fibrinolytic effect is
(a) protease
(b) amylase
(c) lipase
(d) streptokinase
Answer:
(d) streptokinase

Question 12.
Statins used for lowering blood cholesterol level are extracted from
(a) algae
(b) bacteria
(c) viruses
(d) yeast
Answer:
(d) yeast

Question 13.
Monascus purpureus is a yeast commercially used in the production of
(a) citric acid
(b) ethanol
(c) blood cholesterol lowering statins
(d) streptokinase for removing clots from blood vessels
Answer:
(c) blood cholesterol lowering statins

Question 14
is the first step of sewage treatment.
(a) Precipitation
(b) Chlorination
(c) Sedimentation
(d) Aeration
Answer:
(c) Sedimentation

Question 15.
During the primary treatment of sewage, solid particles that settle down are called
(a) floes
(b) primary sludge
(c) activated sludge
(d) anaerobic sludge
Answer:
(b) primary sludge

Question 16.
The purpose of biological treatment of waste water is to
(a) reduce BOD
(b) increase BOD
(c) reduce sedimentation
(d) increase sedimentation
Answer:
(a) reduce BOD

Question 17.
The masses of bacteria held together by slime and fungal filaments to form mesh-like structures are called as
(a) primary sludge
(b) floes
(c) activated sludge
(d) anaerobic sludge
Answer:
(b) floes

Question 18.
BOD is………..in polluted water and in potable water.
(a) more, less
(b) less, more
(c) less in both
(d) medium in both
Answer:
(a) more, less

Question 19.
In the sewage treatment, bacterial floes are allowed to sediment in a settling tank. This sediment is called as
(a) inactivated sludge
(b) activated sludge
(c) primary sludge
(d) secondary sluge
Answer:
(b) activated sludge

Question 20.
Which of the following steps is taken by the Ministry of Environment and Forests to protect rivers from water pollition ?
(a) Ganga Action Plan
(b) Narmada Action Plan
(c) Yamuna Action Plan
(d) Both (a) and (c)
Answer:
(d) Both (a) and (c)

Question 21.
Methanogens, growing anaerobically on cellulosic material produce
(a) methane
(b) methane and carbon dioxide
(c) methane and hydrogen
(d) methane, carbon dioxide and hydrogen
Answer:
(d) methane, carbon dioxide and hydrogen

Question 22.
Which of the following bacteria is present in the rumen of cattle ?
(a) Azotobacter
(b) Rhizobium
(c) Methanobacterium
(d) Azospirillum
Answer:
(c) Methanobacterium

Question 23.
Process of biogas production is
(a) aerobic process
(b) anaerobic process
(c) active process
(d) passive process
Answer:
(b) anaerobic process

Question 24.
Biogas is produced by
(a) aerobic breakdown of biomass
(b) anaerobic breakdown of biomass
(c) with the help of methanogenic bacteria
(d) both (b) and (c)
Answer:
(d) both (b) and (c)

Question 25.
Dragonflies are used to get rid of
(a) mosquitoes
(b) aphids
(c) butterfly caterpillars
(d) both (a) and (b)
Answer:
(a) mosquitoes

Question 26.
A microbial biocontrol agent that can be used to control butterfly caterpillars is
(a) Trichoderma polysporum
(b) Bacillus thuringiensis
(c) Streptococcus
(d) mycorrhiza
Answer:
(b) Bacillus thuringiensis

Question 27.
Bacillus thuringiensis is used to control
(a) bacterial pathogens
(b) fungal pathogens
(c) nematodes
(d) insect pests
Answer:
(d) insect pests

Question 28.
Bacillus thuringiensis (Bt) strains have been used for designing novel
(a) biofertilisers
(b) bio-metallurgical techniques
(c) bio-mineralisation process
(d) bio-insecticidal plants
Answer:
(d) bio-insecticidal plants

Question 29.
Trichoderma harzianum has proved to be a useful microorganism for
(a) gene transfer in higher plants
(b) biological control of soil-borne plant pathogens
(c) bioremediation of contaminated soils
(d) reclamation of wastelands
Answer:
(b) biological control of soil-borne plant pathogens

Question 30.
Baculoviruses (Nucleopolyhedrovirus) do not show
(a) host specificity
(b) narrow spectrum applications
(c) effects on non-target pathogens
(d) utility in IPM programme
Answer:
(c) effects on non-target pathogens

Question 31.
Integrated Pest Management (IPM) discourages the excessive used of
(a) biological methods
(b) chemical pesticides
(c) mechanical methods
(d) all of these
Answer:
(b) chemical pesticides

Question 32.
Which of the following is not used as a biopesticide ?
(a) Trichoderma harzianum
(b) Nucleopolyhedrovirus
(c) Xanthomonas campestris
(d) Bacillus thuringiensis
Answer:
(c) Xanthomonas campestris

Question 33.
Organic farming does not include
(a) green manures
(b) chemical fertilisers
(c) farmyard manures
(d) compost
Answer:
(b) chemical fertilisers

Question 34.
Organic farming includes
(a) use of fertilisers and pesticides of biological origin
(b) IPM (Integrated Pest Management)
(c) locally developed pest resistant varieties
(d) all of these
Answer:
(d) all of these

Question 35.
Living organisms used to enrich the nutrient quality of the soil are called as
(a) biocontrol agents
(b) biofertilisers
(c) synthetic fertilisers
(d) natural fertilisers
Answer:
(d) natural fertilisers

Question 36.
Biofertilisers are
(a) some bacteria and cyanobacteria
(b) fertilisers formed by ploughing in barseem
(c) fertilisers obtained by decay of dead organisms
(d) fertilisers prepared by mixing cattle dung with crop residues
Answer:
(a) some bacteria and cyanobacteria

Question 37.
Biofertilisers are the living organisms which
(a) bring about soil nutrient enrichment
(b) maximise the ecological benefits
(c) minimise the environmental hazards
(d) all of these
Answer:
(d) all of these

Question 38.
Which one of the following can be used as biofertiliser in cotton field ?
(a) Azolla-Anabaena
(b) Streptococcus
(c) Azospirillum
(d) Azotobacter chroococcum
Answer:
(d) Azotobacter chroococcum

Question 39.
The symbiotic association between fungi and roots of higher plants is referred to as
(a) lichen
(b) mycorrhiza
(c) biofertiliser
(d) biocontrol agent
Answer:
(b) mycorrhiza

Question 40.
Cyanobacteria are
(a) heterotrophs
(b) chemotrophs
(c) autotrophs
(d) organotrophs
Answer:
(c) autotrophs

Question 41.
A nitrogen fixing microbe associated with the fern Azolla in rice fields is
(a) Frankia
(b) Rhizobium
(c) Spirulina
(d) Anabaena
Answer:
(d) Anabaena

Question 42.
Azolla pinnata has been found to be an important biofertiliser for paddy crops. This quality is due to the presence of
(a) N₂ fixing bacteria
(b) N₂ fixing cyanobacteria
(c) mycorrhizae
(d) all of these
Answer:
(b) N₂ fixing cyanobacteria

Question 43.
Which of the following is widely used as a successful biofertiliser in Indian rice field ?
(a) Rhizobium
(b) Acacia arabica
(c) Acalypha indica
(d) Azolla pinnata
Answer:
(d) Azolla pinnata

Question 44.
Which of the following options incldes biofertilscrs ?
(a) cowdung manure and farmyard waste
(b) A quick growing crop ploughed back into the field
(c) Nostoc, Oscillatoria
(d) All of these
Answer:
(c) Nostoc, Oscillatoria

Question 45.
Which of the following is a non-symbiotic biofertiliser ?
(a) VAM
(b) Azotobacter
(c) Anabaena
(d) Rhizobium
Answer:
(b) Azotobacter

Question 46.
Nitrogen fixation in root nodules of Alnus is brought about by
(a) Frankia
(b) Azorhizobium
(c) Bradyrhizobium
(d) Clostridium
Answer:
(a) Frankia

Question 47.
The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is
(a) vitamin C
(b) vitamin D
(c) vitamin B₁₂
(d) vitamin E
Answer:
(c) vitamin B₁₂

Question 48.
Wastewater treatment generates a large quantity of sludge, which can be treated by
(a) anaerobic digesters
(b) floe
(c) chemicals
(d) oxidation pond
Answer:
(a) anaerobic digesters

Question 49.
Methanogenic bacteria are not found in
(a) rumen of cattle
(b) gobar gas plant
(c) bottom of water-logged paddy field
(d) activated sludge
Answer:
(d) activated sludge

Question 50.
The primary treatment of wastewater involves the removal of
(a) dissolved impurities
(b) stable particles
(c) toxic substances
(d) harmful bacteria
Answer:
(b) stable particles

Question 51.
BOD of wastewater is estimated by measuring the amount of
(a) total organic matter
(b) biodegradable organic matter
(c) oxygen evolution
(d) oxygen consumption
Answer:
(d) oxygen consumption

Question 52.
Which one of the following alcoholic drinks is produced without distillation ?
(a) Wine
(b) Whisky
(c) Rum
(d) Brandy
Answer:
(a) Wine

Question 53.
The free-living fungus Trichoderma can be used for
(a) killing insects
(b) biological control of plant diseases
(c) controlling butterfly caterpillars
(d) producing antibiotics
Answer:
(b) biological control of plant diseases

Question 54.
Mycorrhiza does not help the host plant in
(a) enhancing its phosphorus uptake capacity
(b) increasing its tolerance to drought
(c) enhancing its resistance to root pathogens
(d) increasing its resistance to insects
Answer:
(d) increasing its resistance to insects

Question 55.
Which one of the following is not a nitrogen-fixing organism ?
(a) Anabaena
(b) Nostoc
(c) Azotobacter
(d) Pseudomonas
Answer:
(d) Pseudomonas

Question 56.
The residue left after methane production from cattle dung is
(a) burnt
(b) burried in land fills
(c) used as manure
(d) used in civil construction
Answer:
(c) used as manure

Question 57.
Methanogens do not produce
(a) oxygen
(b) methane
(c) hydrogen sulphide
(d) carbon dioxide
Answer:
(a) oxygen

Bihar Board 12th Biology Objective Questions and Answers

Bihar Board 12th Biology Objective Answers Chapter 9 Strategies for Enhancement in Food Production

Question 1.
Which of the following is the “bird flu virus” ?
(a) H5N1
(b) Haemophilus influenzae
(c) HIV
(d) Rhino virus
Answer:
(a) H5N1

Question 2.
The infectious and contagious bacterial disease that affects cattle, buffaloes, horses, sheeps and goats is
(a) anthrax
(b) rinderpest
(c) tick fever
(d) necrosis
Answer:
(a) anthrax

Question 3.
Which of the following is an improved variety of chicken ?
(a) Jersey
(b) Leghorn
(c) Himgiri
(d) Kalyan Sona
Answer:
(b) Leghorn

Question 4.
Which of the following is a draught breed of Indian cattle ?
(a) Malvi
(b) Gir
(c) Sahiwal
(d) Deoni
Answer:
(a) Malvi

Question 5.
Holstein-Frisian, Brown Swiss and Jersey are all well known
(a) exotic breeds of cow
(b) exotic breeds of goat
(c) exotic breeds of poultry
(d) animal husbandry scientists
Answer:
(a) exotic breeds of cow

Question 6.
Which one of the following is a breed of cattle ?
(a) Ayrshire
(b) Ghagus
(c) Kadaknath
(d) Scampi
Answer:
(a) Ayrshire

Question 7.
Which one of the following poultry birds is not an English breed ?
(a) Sussex
(b) Australorp
(c) Orpington
(d) Minorca
Answer:
(b) Australorp

Question 8.
High milk yielding cross bred Frieswal cow is the product of
(a) Brown Swiss × Sahiwal
(b) Friesian × Sahiwal
(c) Holstein × Tharparkar
(d) Brown Swiss × Red sindhi
Answer:
(b) Friesian × Sahiwal

Question 9.
What strategy would you suggest if a person wants to evolve a pure line in an animal ?
(a) Cross-breeding
(b) Inbreeding
(c) Out-breeding
(d) artificia insemination
Answer:
(b) Inbreeding

Question 10.
Which of the following statements is not correct regarding inbreeding ?
(a) It is the breeding between animals of the same breed
(b) It decreases homozygosity
(c) It exposes harmful recessive genes
(d) It helps in accumulation os superior genes
Answer:
(b) It decreases homozygosity

Question 11.
The term “inbreeding depression” is related to
(a) increased fertility and productivity
(b) increased milk production
(c) reduced fertility & productivity
(d) reduced milk production
Answer:
(c) reduced fertility & productivity

Question 12.
Continued inbreeding, especially close inbreeding generally results in
(a) inbreeding depression
(b) inbreeding stimulation
(c) inbreeding hybridisation
(d) inbreeding mutation
Answer:
(a) inbreeding depression

Question 13.
The breeding carried out between animals of different breeds is called
(a) out-crossing
(b) cross-breeding
(c) inbreeding
(d) both (a) and (b)
Answer:
(b) cross-breeding

Question 14.
Which of the following is an example of a cross-breed ?
(a) Mule
(b) Hilsa
(c) Hisardale
(d) Sahiwal
Answer:
(c) Hisardale

Question 15.
Hisardale is a new breed of sheep developed in Punjab by crossing
(a) Merino ram and Bikaneri ewe
(b) Assel ram and White leghorn ewe
(c) Rhode Island ram and White leghorn ewe
(d) Cochin ram and Ghagus ewe
Answer:
(a) Merino ram and Bikaneri ewe

Question 16.
Crossing of individuals of two different species to produce a hybrid is called
(a) interspecific hybridisation
(b) intervarietal hybridisation
(c) intergeneric hybridisation
(d) intravarietal hybrididisation
Answer:
(a) interspecific hybridisation

Question 17.
Artificial insemination involves
(a) super ovulation
(b) semen collection
(c) egg collection
(d) embryo collection
Answer:
(b) semen collection

Question 18.
Artificial breeding of cattle is brough about by
(a) artiticial insemination
(b) super ovulation and embryo transplantation
(c) MOET
(d) all of these
Answer:
(d) all of these

Question 19.
MOET stands for
(a) Multiple Ovulation and Egg transfer Technology
(b) Multiple Ovary and Embryo Transfer Technology
(c) Multiple Ovulation Embryo Transfer Technology
(d) Method of Egg Transfer Technology
Answer:
(c) Multiple Ovulation Embryo Transfer Technology

Question 20.
Multiple ovulation embryo transfer technology is related to
(a) transfer of super embryo
(b) transfer of super eggs
(c) super ovulation and embryo transfer
(d) both (a) and (b)
Answer:
(c) super ovulation and embryo transfer

Question 21.
‘Lean meat’ is cosidered to be of high quality because it has
(a) lesser but easily digestible protein
(b) lesser lipid content
(c) more fat that makes the meqt softer
(d) longer table life due to lesser chances of infection
Answer:
(b) lesser lipid content

Question 22.
In livestock breeding experiments, which of the following stages is transferred to surrogate mothers ?
(a) Unfertilised eggs
(b) Fertilised eggs
(c) 8 to 32 celled embryo
(d) Frozen semen
Answer:
(c) 8 to 32 celled embryo

Question 23.
The term ‘apiculture’ refers to
(a) tissue culture
(b) pisciculture
(c) bee-keeping
(d) animal-keeping
Answer:
(c) bee-keeping

Question 24.
Which of the following plays a role in indigenous system of medicine ?
(a) Plant breeding
(b) Fisheries
(c) Apiculture
(d) MOET
Answer:
(c) Apiculture

Question 25.
In honey, the main constituent is
(a) calcium
(b) sugar
(c) protein
(d) water
Answer:
(b) sugar

Question 26.
Beewax is the secretion of badominal glands of
(a) drones
(b) worker bees
(c) queen bees
(d) works and queen bees
Answer:
(b) worker bees

Question 27.
Apis dorsata is
(a) little bee
(b) rock bee
(c) European bee
(d) Indian bee
Answer:
(b) rock bee

Question 28.
The use of honeybee is
(a) to help in pollination
(b) production of bees wax
(c) production of honey
(d) all of these
Answer:
(d) all of these

Question 29.
Keeping beehives in crop fields during flowering period increases
(a) crop yield
(b) honey yield
(c) weeds yield
(d) both (a) and (b)
Answer:
(d) both (a) and (b)

Question 30.
Which of the following is not a freshwater fish ?
(a) Salmon
(b) Mrigal
(c) Catla
(d) Rohu
Answer:
(a) Salmon

Question 31.
Which of the following are common freshwater fishes ?
(a) Mackerel and rohu
(b) Rohu, common carp and Catla
(c) Hilsa and sardine
(d) None of these
Answer:
(b) Rohu, common carp and Catla

Question 32.
Which one of the following is a marine fish ?
(a) Rohu
(b) Hilsa
(c) Catla
(d) Common carp
Answer:
(b) Hilsa

Question 33.
Which one of the following is an exotic carp species ?
(a) Labeo rohita
(b) Crprinus carpio
(c) Labeo bata
(d) Cirrhinus mrigals
Answer:
(b) Crprinus carpio

Question 34.
Aquaculture is the rearing and management of
(a) molluscs and crustaceans
(b) only freshwater fishes
(c) economically useful aquatic plants and animals
(d) only aquatic plants
Answer:
(c) economically useful aquatic plants and animals

Question 35.
Aquaculture does not include
(a) prawns
(b) fishes
(c) silkworms
(d) shell fishery
Answer:
(c) silkworms

Question 36.
Which of the following is correctly matched ?
(a) Sericulture – Fish
(b) Aquaculture – Mosquito
(c) Apiculture – Honeybee
(d) Pisciculture – Silkmoth
Answer:
(c) Apiculture – Honeybee

Question 37.
Germplasm collection is the collection of
(a) germ cells
(b) semens
(c) plants/seeds with all the diverse alleles for all genes
(d) egg cells
Answer:
(c) plants/seeds with all the diverse alleles for all genes

Question 38.
Major percentage of India’s Gross Domestic Product is constituted by
(a) industry
(b) agriculture
(c) export
(d) small scale cottage industry
Answer:
(b) agriculture

Question 39.
The Noble Laureate, who developed semi-dwarf wheat varieties in Mexioc was
(a) Norman E. Borlaug
(b) herbert Boyer
(c) William Harvey
(d) Typhoid Mary
Answer:
(a) Norman E. Borlaug

Question 40.
Jaya and Ratna are the semi-dwarf varieties of
(a) wheat
(b) rice
(c) cowpea
(d) mustard
Answer:
(b) rice

Question 41.
Turnip mosaic disease is caused by
(a) bacteria
(b) viruses
(c) nematodes
(d) fungi
Answer:
(b) viruses

Question 42.
Which of the following dieases is caused by virus ?
(a) Tobacco mosaic
(b) Late blight of potato
(c) Turnip mosaic
(d) Both (a) and (c)
Answer:
(d) Both (a) and (c)

Question 43.
Which of the following is incorrectly matched ?
Disease Causative organism
(a) Black rot of crucifers Bacteria
(b) Brown rust of wheat Fungi
(c) Late blight of potato Virus
(d) Red rot of sugarcane Fungi
Answer:
(c) Late blight of potato Virus

Question 44.
Which of the following dieases is caused by bacteria ?
(a) Tobacco mosaic
(b) Black rot of crucifers
(c) Red rot of sugarcane
(d) Lata blight of potato
Answer:
(b) Black rot of crucifers

Question 45.
Black rust of wheat is caused by
(a) Puccinia
(b) Albugo
(c) Ustilagp
(d) Cystopus
Answer:
(a) Puccinia

Question 46.
Which of the following is incorrectly paired ?
(a) What – Himgiri
(b) Milch breed – Sahiwal
(c) Rice – Ratna
(d) Pusa Komal – Brassica
Answer:
(d) Pusa Komal – Brassica

Question 47.
Yellow mosaic virus resistant variety “Parbhani Kranti” belongs to
(a) bhindi
(b) barley
(c) chilli
(d) cauliflower
Answer:
(a) bhindi

Question 48.
Hairy leaves of many plants are asociated with
(a) resistance to insect pests
(b) resistance to viruses
(c) resistance to fungi
(d) resistance to bacteria
Answer:
(a) resistance to insect pests

Question 49.
Resistance to jassids in cotton plants and to cereal leaf beetle in wheat plants is due to
(a) biochemical characters
(b) physiological characters
(c) morphological characters
(d) none of these
Answer:
(c) morphological characters

Question 50.
Maize generates resistance against stem borers by having
(a) low aspartic acid, high nitrogen and sugar content
(b) low aspartic acid and sugar but high nitrogen content
(c) high aspartic acid and nitrogen but low sugar content
(d) high aspartic acid, low nitrogen and sugar content
Answer:
(d) high aspartic acid, low nitrogen and sugar content

Question 51.
Biofortification refers to the development of crop plants which are
(a) resistant to disease
(b) resistant to insect pests
(c) having improved nutritional quality
(d) having improved iron content
Answer:
(c) having improved nutritional quality

Question 52.
A wheat variety, Atlas 66, which has been used as a donor for improving cultivated wheat is rich in
(a) iron
(b) carbohydrates
(c) proteins
(d) vitamins
Answer:
(c) proteins

Question 53.
Shakti, Ratten and Protina (varieties of maize) are rich in
(a) lysine
(b) glycine
(c) fats
(d) carbohydrates
Answer:
(a) lysine

Question 54.
Which of the following can be used for cultivation of SCP ?
(a) Animal manure
(b) Straw
(c) Molasses
(d) All of these
Answer:
(d) All of these

Question 55.
250 g of Methylophilus methy lotrophus can be expected
to produce tonnes of proteins.
(a) 15
(b) 25
(c) 40
(d) 50
Answer:
(b) 25

Question 56.
Single cell protein can be obtained from
(a) bacteria
(b) algae
(c) fungi
(d) all of these
Answer:
(d) all of these

Question 57.
Which of the following should be used as an explant to generate a disease free plant ?
(a) Anther
(b) Ovary cell
(c) Shoot tip
(d) Young embryo
Answer:
(c) Shoot tip

Question 58.
Hormone responsible for growth of the root in micropropagation is
(a) auxin
(b) gibberellin
(c) cytokinin
(d) abscisic acid
Answer:
(b) gibberellin

Question 59.
somaclones are
(a) somatic hybrids
(b) genetically identical to the original plant
(c) used to recover disease free plants
(d) sterile plants
Answer:
(d) sterile plants

Question 60.
Meristem culture is used
(a) to produce disease free plants
(b) in germplasm conservation
(c) in rapid clonal multiplication
(d) all of these
Answer:
(d) all of these

Question 61.
Meristem culture is the cultue of
(a) axillary or apical shoot meristems
(b) anthers
(c) plant seeds
(d) young embryos
Answer:
(a) axillary or apical shoot meristems

Question 62.
A plant cell without cell wall is called
(a) proplast
(b) protoplast
(c) nucleoplasm
(d) explant
Answer:
(b) protoplast

Question 63.
A somatic hybird between potato and tomato is named as
(a) bomato
(b) mopato
(c) pomato
(d) topamo
Answer:
(c) pomato

Question 64.
The enzymes required to obtain protoplast from a plant cell are
(a) cellulase
(b) chitinase
(c) pectinase
(d) both (a) and (c)
Answer:
(d) both (a) and (c)

Question 65.
The chances of contracting bird flu from a properly cooked (above 100°C) chicken and egg are
(a) very high
(b) high
(c) moderate
(d) none
Answer:
(d) none

Question 66.
A group of animals which are related by descent and share many similarities are referred to as
(a) breed
(b) race
(c) variety
(d) species
Answer:
(a) breed

Question 67.
Inbreeding is carried out in animal husbandry because it
(a) increases vigour
(b) improves the breed
(c) increases heterozygosity
(d) increases homozygosity
Answer:
(d) increases homozygosity

Question 68.
Sonalikea and Kalyan Sona are varieties of
(a) wheat
(b) rice
(c) millet
(d) tobacco
Answer:
(a) wheat

Question 69.
Which one of the following is not a fungal disease ?
(a) Rust of wheat
(b) Smut of Bajra
(c) Black rot of crucifers
(d) Red rot of sugarcane
Answer:
(c) Black rot of crucifers

Question 70.
Fungicides and antibiotics are chemicals that
(a) enhance yield and disease resistance
(b) kill pathogenic fungi and bacteria, respectively
(c) kill all pathogenic microbes
(d) kill pathogenic bacteria and fungi respectively
Answer:
(b) kill pathogenic fungi and bacteria, respectively

Question 71.
Use of certain chemicals and radiation to change the base sequences of genes of crop plants is termed
(a) recombinant DNA technology
(b) transgenic mechanism
(c) mutation breeding
(d) gene therapy
Answer:
(c) mutation breeding

Question 72.
The scientific process by which crop plants are enriched with certain desirable nutrients is called
(a) crop protection
(b) breeding
(c) bio-fortification
(d) bio-remediation
Answer:
(c) bio-fortification

Question 73.
The term ‘totipotency’ refers to the capacity of a
(a) cell to generate whole plant
(b) bud to generate whole plant
(c) seed to germinate
(d) cell to enlarge in size
Answer:
(a) cell to generate whole plant

Question 74.
An explant is
(a) dead plant
(b) part of the plant
(c) part of the plant used in tissue culture
(d) part of the plant that expresses a specific gene
Answer:
(c) part of the plant used in tissue culture

Question 75.
The biggest constraint of plant breeding is
(a) availability of desirable gene in the crop and its wild relatives
(b) infrastructure
(c) trained manpower
(d) transfer of genes from unrelated sources
Answer:
(a) availability of desirable gene in the crop and its wild relatives

Question 76.
Lysine and tryptophan are
(a) proteins
(b) non-essential amino acids
(c) essential amino acids
(d) aromatic amino acids
Answer:
(c) essential amino acids

Question 77.
Micropropagation is
(a) propagation oif microbes in vitro
(b) propagation of plants in vitro
(c) propagation of cells in vitro
(d) growing plants on smaller scale
Answer:
(b) propagation of plants in vitro

Question 78.
Protoplast is
(a) another name for protoplasm
(b) an animal cell
(c) a plant cell without a cell wall
(d) a plant cell
Answer:
(c) a plant cell without a cell wall

Question 79.
To isolate protoplast, one needs
(a) pectiriase
(b) cellulase
(c) both pectinase and cellulase
(d) chitinase
Answer:
(c) both pectinase and cellulase

Question 80.
Which one of the following is a marine fish ?
(a) Rohu
(b) Hilsa
(c) Catla
(d) Common Carp
Answer:
(b) Hilsa

Question 81.
Which one of the following products of apiculture is used in cosmetics and polishes ?
(a) Honey
(b) Oil
(c) Wax
(d) Royal jelly
Answer:
(c) Wax

Question 82.
More than 70 percent of livestock population is in
(a) Denmark
(b) India
(c) China
(d) India and China
Answer:
(d) India and China

Question 83.
The agriculture sector of India employs about
(a) 50 percent of the population
(b) 70 percent of the population
(c) 30 percent of the population
(d) 60 percent of the population
Answer:
(d) 60 percent of the population

Question 84.
33 percent of India’s (Gross Domestic Product) comes from
(a) industry
(b) agriculture
(c) export
(d) small-scale cottage industries
Answer:
(b) agriculture

Question 85.
A collection of all the alleles of all the genes of a crop plant is called
(a) germplasm collection
(b) protoplasm collection
(c) herbarium
(d) somaclonal collection
Answer:
(a) germplasm collection

Bihar Board 12th Chemistry Objective Questions and Answers

Bihar Board 12th Chemistry Objective Answers Chapter 9 Coordination Compounds

Question 1.
Copper sulphate dissolves in ammonia due to the formation of
(a) Cu₂O
(b) [Cu(NH₃)₄]SO₄
(c) [Cu(NH₃)₄]OH
(d) [Cu(H₂O)₄]SO₄
Answer:
(b) [Cu(NH₃)₄]SO₄

Question 2.
The number of ions given by [Pt(NH₃)₆]Cl₄ inaqueous solution will be
(a) two
(b) three
(c) five
(d) eleven
Answer:
(c) five

Question 3.
When one mole of each of the following complexes is treated with excess of AgNO₃, which will give maximum amount of AgCl ?
(a) [Co(NH₃)₆]Cl₃
(b)[Co(NH₃)₅CI]Cl₂
(c) [Co(NH₃)₄Cl₂]Cl
(d) [Co(NH₃)₃Cl₃]
Answer:
(a) [Co(NH₃)₆]Cl₃

Question 4.
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 5.
Which of the following primary and secondary valencies are not correctly marked against the compounds ?
(a) [Cr(NH₃)₆]Cl₃, p = 3,s = 6
(b) K₂[Pt(Cl₄], p = 2, s = 4
(c) [Pt(NH₃)₂CI₂], p = 2, s = 4
(d) [Cu(NH₃)₄]SO₄ , p = 4, s = 4
Answer:
(d) [Cu(NH₃)₄]SO₄ , p = 4, s = 4

Question 6.
The ligand N(CH₂CH₂NH₂)₃ is
(a) bidentate
(b) tridentate
(c) tetradentate
(d) pentadentate
Answer:
(c) tetradentate

Question 7.
Which of the following is a tridentate ligand ?
(a)EDTA^4-
(b) (COO)₂^–
(c) dien
(d) NO₂
Answer:
(c) dien

Question 8.
Among the following, which are ambidentate ligands ?
(i)SCN^–
(ii) NO
(iii) NO;
(iv) C₂O_4^–
(a) (i) and (iii)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Answer:
(a) (i) and (iii)

Question 9.
Which of the following ligands form a chelate ?
(a) Acetate
(b) Oxalate
(c) Cyanide
(d) Ammonia
Answer:
(b) Oxalate

Question 10.
Which of the following is not a neutral ligand ?
(a) H₂O
(b) NH₃
(c) ONO
(d) CO
Answer:
(c) ONO

Question 11.
Which of the following ligands will not show chelation ?
(a) EDTA
(b) DMG
(c) Ethane – 1, 2-diamine
(d) SCN^–
Answer:
(d) SCN^–

Question 12.
The coordination number and the oxidation state of the  element E in the complex [E(en)₂(C₂O₄)]NO₂ (where (en) is ethylenediamine) are, respectively
(a) 6 and 3
(b) 6 and 2
(c) 4 and 2
(d) 4 and 3
Answer:
(a) 6 and 3

Question 13.
The correct IUPAC name of the coordination compound K₃[Fe(CN)₅NO] is
(a) potassium pentacyanonitrosylferrate (II)
(b) potassium pentacyanonitroferrate(III)
(c) potassium nitritopentacyanoeferrate (IV)
(d) potassium nitritepentacyanoiron (II)
Answer:
(a) potassium pentacyanonitrosylferrate (II)

Question 14.
Correct formula of tetraamminechloronitroplatinum (IV) sulphate can be written as
(a) [ Pt(NH₃ )₄ (ONO)Cl ]SO₄
(b) [Pt(NH₃)₄Cl₂NO₂]₂SO₄
(c) [Pt(NH₃)₄(NO₂)Cl]SO₄
(d) [PtCl (ONO) NH₃(SO₄)]
Answer:
(c) [Pt(NH₃)₄(NO₂)Cl]SO₄

Question 15.
Which among the following will be named as dibromidobis (ethylenediamine) chromium (III) bromide ?
(a) [Cr(en)₂Br₂]Br
(b) [Cr(en)Br₄ ]^–
(c) [Cr(en)Br₂]Br
(d) [Cr(en)₃]Br₃
Answer:
(a) [Cr(en)₂Br₂]Br

Question 16.
The name of the compound [Co(NH₃)5NO₂]Cl₂ will be
(a) pentaamminonitrocobalt (II) chloride
(b) pentaamminenitrochloridecobaltate (III)
(c) pentaamminenitrocobalt (III) chloride
(d) pentanitrosoamminechlorocobaltate (III)
Answer:
(c) pentaamminenitrocobalt (III) chloride

Question 17.
How many geometrical isomers are there for [Co(NH₃)₂Cl₄]^– (octahedral) and [AuCl₂Br₂] (square planar) ?
(a) Two cis and trans, no geometrical isomers
(b) Two cis and trans, two cis and trans
(c) No geometrical isomers, two cis and trans
(d) No geometrical isomers, no geometrical isomers
Answer:
(b) Two cis and trans, two cis and trans

Question 18.
Which of the following will not show geometrical isomerism ?
(a) [Cr(NH₃)₄Cl₂]Cl
(b) [Co(en)₂Cl₂]CI
(c) [Co(NH₃)₅NO₂]Cl₂
(d) [Pt(NH₃)₂Cl₂]
Answer:
(c) [Co(NH₃)₅NO₂]Cl₂

Question 19.
Which of the following shows maximum number of isomers ?
(a) [Co(NH₃)₄Cl₂]
(b) [Ni(en)(NH₃)₄]²⁺
(c) [Ni(C₂O₄)(en)₂]^2-
(d) [Cr(SCN)₂(NH₃)₄]⁺
Answer:
(d) [Cr(SCN)₂(NH₃)₄]⁺

Question 20.
Which of the following complexes exists as pair of enantiomers ?
(a) [Co(NH₃)₄Cl₂]⁺
(b) [Cr(en)₃]³⁺
(c) [Co(P(C₂H₅)₃)₂ClBr]
(d) trans- [Co(en)₂Cl₂ ]⁺
Answer:
(b) [Cr(en)₃]³⁺

Question 21.
Two isomers of a compound Co(NH₃)₃Cl₃(MA₃B₃type) are shown in the figures.

The isomers can be classified as
(a) (i) fac-isomers (ii) mer-isomer
(b) (i) optical-isomer (ii) trans-isomer
(c) (i) mer-isomer (ii) fac-isomer
(d) (i) trans-isomer (ii) cis-isomer
Answer:
(a) (i) fac-isomers (ii) mer-isomer

Question 22.
Which of the following compounds exhibits linkage isomerism ?
(a) [Co(en)₃]Cl₃
(b) [Co(NH₃)₆][Cr(en)₃]
(c) [Co(en)₂ (NO₂)Cl]Br
(d) [Co(NH₃)₅Cl]Br₂
Answer:
(c) [Co(en)₂ (NO₂)Cl]Br

Question 23.
[Pt(NH3)₄][CuCl₄] and tCu(NH₃)₄][PtCl₄] are known is
(a) ionisation isomers
(b) coordination isomers
(c) linkage isomers
(d) polymerisation isomers
Answer:
(b) coordination isomers

Question 24.
Which of the following isomers will give white precipitate with BaCl₂ solution ?
(a) [Co(NH₃)₅SO₄]Br
(b) [Co(NH₃)₅ Br]SO₄
(c) [Co(NH₃)₄(SO₄)₂]Br
(d) [Co(NH₃)₄ Br(SO₄)]
Answer:
(b) [Co(NH₃)₅ Br]SO₄

Question 25.
CrCl₃.6H₂O exists in different isomeric forms which show different colours like violet and green. This is due to
(a) ionisation isomerism
(b) coordination isomerism
(c) optical isomerism
(d) hydrate isomerism
Answer:
(d) hydrate isomerism

Question 26.
The hybridisation involved in [Co(C₂O₄)₃]^3- is
(a) sp³d²
(b) sp³d³
(c) dsp³
(d) d²sp³
Answer:
(d) d²sp³

Question 27.
Which of the following complexes will have tetrahedral shape ?
(a) [PdCl₄]^2-
(b) [Pd(CN)₄]^2-
(c) [Ni(CN)₄l^2-
(d) [NiCl₄]^2-
Answer:
(d) [NiCl₄]^2-

Question 28.
The complex ion which has no d-electrons in the central metal atom is
(a) [MnO₄]^–
(b) [Co(NH₃)₆]³⁺
(c) [Fe(CN)₆]^3-
(d) [Cr(H₂O)₆]⁺
Answer:
(a) [MnO₄]^–

Question 29.
The lowest value paramagnetism is shown by
(a) [Co(CN)₆]^3-
(b) [Fe(CN)₆]^3-
(c) [Cr(CN)₆]^3-
(d) [Mn(CN)₆]^3-
Answer:
(a) [Co(CN)₆]^3-

Question 30.
[CoF₆]^3- is
(a) paramagnetic and undergoes sp³d² hybridisation
(b) diamagnetic and undergoes d²sp³ hybridisation
(c) paramagnetic and undergoes sp³d hybridisation
(d) diamagnetic and undergoes sp³ hybridisation
Answer:
(a) paramagnetic and undergoes sp³d² hybridisation

Question 31.
The magnitude of magnetic moment (spin only) of [NiCl₄]^2- will be
(a) 2.82B.M.
(b) 3.25B.M.
(c) 1.23 B.M.
(d) 5.64 B.M.
Answer:
(a) 2.82B.M.

Question 32.
Which of the following has largest paramagnetism ?
(a) [Cr(H₂O)₆]³⁺
(b) [Fe(H₂O)₆]²⁺
(c) [Cu(H₂O)₆]²⁺
(d) [Zn(H₂O)₂]²⁺
Answer:
(b) [Fe(H₂O)₆]²⁺

Question 33.
Which of the following descriptions about [FeCl₆ ]^4- is correct about the complex ion ?
(a) sp³ d, inner orbital complex, diamagnetic
(b) sp³ d², outer orbital complex, paramagnetic
(c) d²sp³, inner orbital complex, paramagnetic
(d) d²sp³, outer orbital complex, diamagnetic
Answer:
(b) sp³ d², outer orbital complex, paramagnetic

Question 34.
When excess of ammonia is added to copper sulphate solution, the deep blue coloured complex is formed. The complex is
(a) tetrahedral and paramagnetic
(b) tetrahedral and diamagnetic
(c) square planar and diamagnetic
(d) square planar and paramagnetic
Answer:
(d) square planar and paramagnetic

Question 35.
Among the following compounds which is both paramagnetic and coloured ?
(a) K₂Cr₂O₇
(b) [Co(SO₄)]
(c) (NH₄)₂[TiCl₆]
(d) K₃[Cu(CN)₄]
Answer:
(b) [Co(SO₄)]

Question 36.
The spin only magnetic moment value of Cr(CO)₆ is
(a) 2.84 B.M.
(b) 4.90 B.M.
(c) 5.92 B.M.
(d) O.B.M.
Answer:
(d) O.B.M.

Question 37.
Which of the following complexes will show maximum paramagnetism ?
(a) 3d⁴
(b) 3d⁵
(c) 3d⁶
(d) 3d⁷
Answer:
(b) 3d⁵

Question 38.
Electronic configuration of [Cu(NH₃)₆]²⁺ on the basis of crystal field splitting theory is

Answer:
(b)

Question 39.
Which of the following shall form an octahedral complex ?
(a) d⁴ (low spin)
(b) d⁸ (high spin)
(c) d⁶ (low spin)
(d) None of these
Answer:
(c) d⁶ (low spin)

Question 40.
The value of the ‘spin only’ magnetic moment for one of the following configuration is 2.84 BM. The correct one is
(a) d⁴(in strong ligand field)
(b) d⁴ (in weak ligand field)
(c) d³ (in weak as well as in strong fields)
(d) d⁵ (in strong ligand field)
Answer:
(a) d⁴(in strong ligand field)

Question 41.
CuSO₄.5H₂O is blue in colour while CuSO₄ is colourless due to
(a) presence of strong field ligand in CuSO₄.5H₂O
(b) due to absence of water (ligand), d-d transitions are not possible in CuSO₄
(c) anhydrous CuSO₄ undergoes d-d transitions due to crystal field splitting
(d) colour is lost due to loss of unpaired electrons
Answer:
(b) due to absence of water (ligand), d-d transitions are not possible in CuSO₄

Question 42.
[Fe(CN)₆]^4- and [Fe(H₂O)₆]²⁺ show different colours in dilute solution because
(a) CN^– is a strong field ligand and H₂O is a weak field ligand hence magnitude of CFSE is different
(b) both CN^– and H₂O absorb same wavelength of energy
(c) complexes of weak field ligands are generally colourless
(d) the sizes of CN^– and H₂O are different hence their colours are also different
Answer:
(d) the sizes of CN^– and H₂O are different hence their colours are also different

Question 43.
The terminal and bridged CO ligands in the compound [Co₂(CO)₈] are respectively
(a) 0, 2
(b) 6, 1
(c) 5,2
(d) 6, 2
Answer:
(b) 6, 1

Question 44.
The geometry possessed by [Ni(CO)₄] is
(a) tetrahedral
(b) square planar
(c) linear
(d) octahedral
Answer:
(a) tetrahedral

Question 45.
Cr-C bond in the compound [Cr(CO)₆] shows 71- character due to
(a) covalent bonding
(b) coordinate bonding
(c) synergic bonding
(d) ionic bonding
Answer:
(c) synergic bonding

Question 46.
The overall complex dissociation equilibrium constant for the complex [Cu(NH₃)₄]²⁺ ion will be (P₄ for this complex is 2.1 x 10¹³)
(a) 7 x 10^-14
(b) 2.1 x 10¹³
(c) 11.9 x 10^-2
(d) 2.1 x 10^–3
Answer:
(a) 7 x 10^-14

Question 47.
Mark the incorrect match
(a) Insulin – Zinc
(b) Haemoglobin – Iron
(c) Vitamin Bp –  Cobalt
(d) Chlorophyll – Chromium
Answer:
(d) Chlorophyll – Chromium

Question 48.
The correct IUPAC name of [Pt(NH₃)₂Cl₂] is ……………….
(a) diamminedichloridoplatinum (II)
(b) diamminedichloridoplatinum (IV)
(c) diamminedichloridoplatinum (0)
(d) dichloridodiammineplatinum (IV)
Answer:
(a) diamminedichloridoplatinum (II)

Question 49.
The stabilisation of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species ?
(a) [Fe(CO)₅]
(b) [Fe(CN)₆]-
(c) [Fe(C₂O₄)₃]^3-
(d) [Fe(H₂O)₆]³⁺
Answer:
(c) [Fe(C₂O₄)₃]^3-

Question 50.
Indicate the complex ion which shows geometrical isomerism.
(a) [Cr(H₂O)₄Cl₂]⁺
(b) [Pt(NH₃)₃Cl]
(c) [Co(NH₃)₆]³⁺
(d) [Co(CN)₅(NC)]^3-
Answer:
(a) [Cr(H₂O)₄Cl₂]⁺

Question 51.
The CFSE for octa hedral [CoCl₆]^4- is 18,000 cm^-1. The CFSE for tetrahedral [CoCl₄ ]² will be
(a) 18,0000 cm^-1
(b) 16,000 cm^-1
(c) 8,000 cm^-1
(d) 20,000 cm^-1
Answer:
(c) 8,000 cm^-1

Question 52.
The compounds [Co(SO₄)(NH₃)_s] Br and [Co(SO₄)(NH₃)₅]Cl represent
(a) linkage isomerism
(b) ionisation isomerism
(c) coordination isomerism
(d) no isomerism
Answer:
(d) no isomerism

Question 53.
A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent ?
(a) Thiosulphato
(b) Oxalato
(c) Glycinato
(d) Ethane-1. 2-diamine
Answer:
(a) Thiosulphato

Question 54.
Which of the following species is not expected to be a ligand ?
(a) NO
(b) NH₄
(c) NH₂CH₂CH₂NH₂
(d) CO
Answer:
(b) NH₄

 

 

Bihar Board 12th Biology Objective Questions and Answers

Bihar Board 12th Biology Objective Answers Chapter 11 Biotechnology: Principles and Processes

Question 1.
Who is the father of genetic engineering ?
(a) Steward Linn
(b) Stanley Cohen
(c) Paul Berg
(d) Kary Mullis
Answer:
(c) Paul Berg

Question 2.
Plasmid used to construct the first recombinant DNA was isolated from which bacterium species ?
(a) Escherichia coli
(b) Salmonelia typhimurium
(c) Agrobacterium tumefaciens
(d) Thermus aquaticus
Answer:
(b) Salmonelia typhimurium

Question 3.
The term ‘molecular scissors’ refers to
(a) recombinant DNA
(b) restriction enzymes
(c) Taq polymerase
(d) palindromic nucleotide sequences.
Answer:
(b) restriction enzymes

Question 4.
The term ’chemical knife’ refers to
(a) polymerases
(b) endonucleases
(c) ribonucleases
(d) cellulases.
Answer:
(b) endonucleases

Question 5.
One of the key factors, which makes the plasmid the vector in genetic engineering is
(a) its resistance to antibiotics
(b) its resistance to restriction enzymes
(c) its ability to carry a foreign gene
(d) its ability to cause infection in the host.
Answer:
(c) its ability to carry a foreign gene

Question 6.
The term ’recombinant DNA’ refers to
(a) DNA of the host cell
(b) DNA with a piece of foreign DNA
(c) DNA with selectable marker
(d) DNA with more than one recognition sites.
Answer:
(b) DNA with a piece of foreign DNA

Question 7.
The term ’chimeric DNA’ refers to
(a) DNA with overhanging stretches
(b) DNA with palindromic sequence
(c) a recombinant DNA
(d) molecular scissors.
Answer:
(c) a recombinant DNA

Question 8.
Which of the following is not a tool of genetic engineering ?
(a) Cloning vector
(b) Restriction enzyme
(c) Foreign DNA
(d) GMO
Answer:
(d) GMO

Question 9.
The first restriction endonuclease isolated was
(a) EcoRI
(b) BamHI
(c) Sail
(d) Hindll
Answer:
(d) Hindll

Question 10.
The letter ’R’ in EcoRI is derived from
(a) the name of genus
(b) the name of strain
(c) the name of species
(d) the term ‘restriction1.
Answer:
(b) the name of strain

Question 11.
The source of the restriction enzyme Hindlll is
(a) Escherichia coli RY 13
(b) Haemophilus influenzae Rd
(c) Bacillus amyloliquefaciens H
(d) Streptomyces albus.
Answer:
(d) Streptomyces albus.

Question 12.
The sticky ends of a fragmented DNA molecule are made of
(a) calcium salts
(b) endonuclease enzyme
(c) unpaired bases
(d) methyl groups.
Answer:
(c) unpaired bases

Question 13.
Identify the palindromic sequence in the following.
(a) \(\frac{\text { GAATTC }}{\text { CTTUUG }}\)
(b) \(\frac{\mathrm{GGATCC}}{\mathrm{CCTAGG}}\)
(C) \(\frac{\mathrm{GGATCC}}{\mathrm{CCTAGG}}\)
(d) \(\frac{\text { GGATA }}{\text { GCTAA }}\)
Answer:
(b) \(\frac{\mathrm{GGATCC}}{\mathrm{CCTAGG}}\)

Question 14.
Which of the following statements is not correct regarding EcoRI restriction endonuclease enzyme ?
(a) It is isolated from Escherichia coli RY 13.
(b) Its recognition sequence is 5′-GAATTC-3′ 3′- CTTAAG-5′.
(c) It produces complementary blunt ends.
(d) None of these
Answer:
(c) It produces complementary blunt ends.

Question 15.
If a plasmid vector is digested with EcoRI at a single site, then
(a) one sticky end will be produced
(b) two sticky ends will be produced
(c) four sticky ends will be produced
(d) six sticky ends will be produced.
Answer:
(b) two sticky ends will be produced

Question 16.
Which of the following tools of recombinant DNA technology is incorrectly paired with its use ?
(a) EcoRI – Production of sticky ends
(b) DNA ligase – Multiplication of rDNA molecules
(c) ori – copy number
(d) Selectable marker – Identification of transformants
Answer:
(b) DNA ligase – Multiplication of rDNA molecules

Question Question 17.
Which one of the following characteristic is generally not preferred for a cloning vector ?
(a) An origin of replication
(b) An antibiotic resistance marker
(c) Multiple restriction sites
(d) A high copy number
Answer:
(c) Multiple restriction sites

Question 18.
Which of the following is not a cloning vector ?
(a) Cosmid
(b) pBR322
(c) Sail
(d) Phagemid
Answer:
(c) Sail

Question 19.
pBR322 was the first artificial cloning vector to be constructed. What does “BR” stands for ?
(a) Bacteriophage and Recombinant
(b) Boliver and Rodriguez
(c) Boyer and Replicative
(d) None of these
Answer:
(b) Boliver and Rodriguez

Question 20.
ce gene (tetR) has recognition site for which of the following res
In pBR322, tetracycline resistantriction endonuclease ?
(a) Hind III
(b) BamHI
(c) EcoRI
(d) PstI
Answer:
(d) PstI

Question 21.
What will be the effect if pBR322, a cloning vector does not carry ‘ori’ site ?
(a) Sticky ends will not produce
(b) Transformation will not takes place.
(c) The cell will transform into a tumour cell.
(d) Replication will not takes place.
Answer:
(d) Replication will not takes place.

Question 22.
An advantage of using yeasts rather than bacteria as recipient cells for the recombinant DNA of eukaryotes is that yeasts can
(a) produce restriction enzymes
(b) excise introns from the RNA transcript
(c) remove methyl groups
(d) reproduce more rapidly.
Answer:
(b) excise introns from the RNA transcript

Question 23.
Which of the following bacteria is used as a vector for plant genetic engineering ?
(a) Agrobacterium tumefacines
(b) Bacteriophages
(c) Thermus aquaticus
(d) Pyrococcus furiosus
Answer:
(a) Agrobacterium tumefacines

Question 24.
a crown gall bacterium, is called as ‘natural genetic engineer’ of plants.
(a) Escherichia coli
(b) Streptomyces albus
(c) Agrobacterium tumefaciens
(d) Azotobacter
Answer:
(c) Agrobacterium tumefaciens

Question 25.
The term “competent” refers to
(a) increasing the competition between cells
(b) making cells impermeable for DNA
(c) Increasing the efficiency with which DNA enters the bacterium through pores in its cell wall
(d) making cells permeable for divalent cations.
Answer:
(c) Increasing the efficiency with which DNA enters the bacterium through pores in its cell wall

Question 26.
Micro-injection is a method used to
(a) produce sticky ends of DNA
(b) provide protection against pathogen
(c) purify the DNA
(d) inject recombinant DNA into the nucleus of an animal cell.
Answer:
(d) inject recombinant DNA into the nucleus of an animal cell.

Question 27.
Which of the following is required for micro-injection method of gene transfer ?
(a) Micro-particles
(b) Micro-pipettes
(c) Divalent cations
(d) UV radiations
Answer:
(b) Micro-pipettes

Question 28.
In biolistic method of gene transfer, the microparticles coated with foreign DNA are bombarded into target cells at a very high velocity. These microparticles are made up of
(a) silver or tungsten
(b) arsenic or silver
(c) gold or tungsten
(d) none of these.
Answer:
(c) gold or tungsten

Question 29.
During isolation of genetic material, the chemical used to precipitate out the purified DNA is
(a) bromophenol blue
(b) Chilled ethanol
(c) ethidium bromide
(d) both (a) and (c).
Answer:
(b) Chilled ethanol

Question 30.
The polymerase chain reaction is a technique used for
(a) amplification of DNA
(b) amplification of enzymes
(c) amplification of proteins
(d) all of these.
Answer:
(a) amplification of DNA

Question 31.
Process used for amplification or multiplication of DNA in DNA fingerprinting is
(a) polymerase chain reaction
(b) southern blotting
(c) northern blotting
(d) none of these.
Answer:
(a) polymerase chain reaction

Question 32.
Enzyme ‘Taq polymerase’ used in PCR, has been isolated from bacterium
(a) Agrobacterium tumefaciens
(b) Thermus aquaticus
(c) Streptomyces albus
(d) Escherichia coli
Answer:
(b) Thermus aquaticus

Question 33.
Which one of the following is not a correct match ?
(a) Tumour inducing – Ti plasmid
(b) DNA probe – Identifies the desired DNA
(c) PCR – DNA staining
(d) Agarose – Seaweeds
Answer:
(c) PCR – DNA staining

Question 34.
The correct sequence of different steps of polymerase chain reaction is
(a) annealing → denaturation → extension
(b) denaturation → extension → annealing
(c) denaturation → annealing → extension
(d) extension → denaturation → annealing.
Answer:
(c) denaturation → annealing → extension

Question 35.
Which of the following is required to perform polymerase chain reaction ?
(a) Primers, dNTPs and DNA polymerase
(b) DNA, CaCl₂ and nuclease
(c) Mg + 2, DNA
(d) Both (a) and (c)
Answer:
(d) Both (a) and (c)

Question 36.
Which of the following is not used to transfer the recombinant DNA into the host ?
(a) Micro-injection method
(b) Gene gun method
(c) Bioreactors
(d) Disarmed pathogen vectors
Answer:
(c) Bioreactors

Question 37.
A device in which large volume of living cells are
cultured in order to get a specific product is called
(a) PCR
(b) agitator
(c) bioreactor
(d) assimilator.
Answer:
(c) bioreactor

Question 38.
Rising of dough is due to
(a) multiplication of yeast
(b) production of CO₂
(c) emulsification
(d) hydrolysis of wheat flour starch into sugars.
Answer:
(b) production of CO₂

Question 39.
An enzyme catalysing the removal of nucleotides from the ends of DNA is
(a) endonuclease
(b) exonuclease
(c) DNA ligase
(d) Hind II.
Answer:
(b) exonuclease

Question 40.
The transfer of genetic material from one bacterium to another through the mediation of a vector like virus is termed as
(a) transduction
(b) conjugation
(c) transformation
(d) translation.
Answer:
(a) transduction

Question 41.
Which of the following is not required in the preparation of a recombinant DNA molecule ?
(a) Restriction endonuclease
(b) DNA ligase
(c) DNA fragments
(d) E. coli
Answer:
(d) E. coli

Question 42.
In agarose gel electrophoresis, DNA molecules are
separated on the basis of their
(a) charge only
(b) size only
(c) charge to size ratio
(d) all of the above.
Answer:
(b) size only

Question 43.
While isolating DNA from bacteria, which of the following enzymes is not used ?
(a) Lysozyme
(b) Ribonuclease
(c) Deoxyribonuclease
(d) Protease
Answer:
(c) Deoxyribonuclease

Question 44.
Which of the following has popularised the PCR (polymerase chain reactions) ?
(a) Easy availability of DNA template
(b) Availability of synthetic primers
(c) Availability of cheap deoxyribonucleotides
(d) Availability of ‘thermostable’ DNA polymerase
Answer:
(d) Availability of ‘thermostable’ DNA polymerase

Question 45.
An antibiotic resistance gene in a vector usually helps in the selection of
(a) competent cells
(b) transformed cells
(c) recombinant cells
(d) none of the above.
Answer:
(b) transformed cells

Question 46.
Significance of ‘heat shock’ method in bacterial transformation is to facilitate
(a) binding of DNA to the cell wall
(b) uptake of DNA through membrane transport proteins
(c) uptake of DNA through transient pores in the bacterial cell wall
(d) expression of antibiotic resistance gene.
Answer:
(c) uptake of DNA through transient pores in the bacterial cell wall

Question 47.
Which of the following is not a source of restriction endonuclease ?
(a) Haemophilus influenzae
(b) Escherichia coli
(c) Entamoeba coli
(d) Bacillus amyloliquifaciens
Answer:
(c) Entamoeba coli

Question 48.
Which of the following steps are catalysed by Taq polymerase in a PCR reaction ?
(a) Denaturation of template DNA
(b) Annealing of primers to template DNA
(c) Extension of primer end on the template DNA
(d) All of the above
Answer:
(c) Extension of primer end on the template DNA

Question 49.
Who among the following was awarded the Nobel Prize for the development of PCR technique ?
(a) Herbert Boyer
(b) Hargovind Khurana
(c) Kary Mullis
(d) Arthur Komberg
Answer:
(c) Kary Mullis

Question 50.
Which of the following statements does not hold true for restriction enzyme ?
(a) It recognises a palindromic nucleotide sequence.
(b) It is an endonuclease.
(c) It is isolated from viruses.
(d) It produces the same kind of sticky ends in different DNA molecules.
Answer:
(c) It is isolated from viruses.

Bihar Board 12th Maths Model Papers

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

Time : 3 Hours 15 Min
Full Marks: 100

Instructions for the candidates :

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

Objective Type Questions

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Question 20.
The function f(x) = e^2x is
(a) strictly increasing
(b) strictly decreasing
(c) neither incrasing nor decreasing
(d) None of these
Answer:
(a) strictly increasing

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

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

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

Question 24.
The antiderivative of (ax + b)² is

Answer:
\(\frac{1}{3 a}(a x+b)^{3}+C\)

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

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

Question 27.
If f(a + b – x) = f(x) then \(\int_{a}^{b} x f(x) d x\) is equal to

Answer:
\(\frac{a+b}{2} \int_{a}^{b} f(x) d x\)

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

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

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

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

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

Question 33.
The integrating factor at the diff eqⁿ (1 – y²) \(\frac{d x}{d y}\) + yx = ay (-1 < y < -1) is

Answer:
(d) \(\frac{1}{\sqrt{1-y^{2}}}\)

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

Question 35.
The generval solution of diff. eqⁿ e^xdy + (ye^x + 2x)dx = 0 is
(a) xe^x + x² = C
(b) xe^y + y² = C
(c) ye^x + x² = C
(d) ye^x + x² = C
Answer:
(c) ye^x + x² = C

Question 36.
If the adjacent side of parallelogram are \(\vec{a}\) and \(\vec{b}\) then its area is

Answer:
(a) \(|\vec{a} \times \vec{b}|\)

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

Question 38.
If \(\vec{a}\) and \(\vec{b}\) are two vectors then \((\vec{a}+\vec{b}) \cdot(\vec{a}-\vec{b})\) is equal to

Answer:
(d) \(2(a \times b)\)

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

Question 40.
If θ be the angle between the vectors \(\vec{a}\) and \(\vec{b}\) then sin θ is

Answer:
(a) \(\frac{\vec{a} \cdot \vec{b}}{|\vec{a} \| \vec{b}|}\)

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

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

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

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

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

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

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

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

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

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

Non – Objective Type Questions

Short Answer Type Questions

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

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

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

Question 3.
Prove that the binary opeation * on the set N such that a * b = \(\frac{a+b}{2}\) ∀ a,b,∈ N is commutative but not associative.
Answer:

Thus the binary operation * is commutative but not associative

Question 4.
Find the value of cot [tan^-1 a + cot^-1 a]
Answer:

Question 5.
Prove that \(\sin ^{-1} \frac{2 \sqrt{2}}{3}+\sin ^{-1} \frac{1}{3}=\frac{\pi}{2}\)
Answer:

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

Question 7.
If A = \(\left[\begin{array}{lll}
3 & \sqrt{3} & 2 \\
4 & 2 & 0
\end{array}\right]\) then prove that (A’)’ = A
Answer:

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

Question 9.
Find the value of x and y if \(\left|\begin{array}{ll}
2 & 3 \\
y & x
\end{array}\right|=4\) and \(\left|\begin{array}{ll}
x & y \\
2 & 1
\end{array}\right|=\frac{7}{2}\)
Answer:

⇒ y = -3
Multiplying (2) by 2 and subtract (1), we get Putting the value of y in (2), we get

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

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

Question 12.
If x = at², y = 2at. then find that dy/dx
Answer:

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

Question 14.
Evaluate: \(\int_{0}^{1} x(1-x)^{23} d x\)
Answer:
Let z = 1 – x, then dz = -dx and x = 1 – z
when x = 0, z = 1 and when x = 1, z = 0

Question 15.
Evaluate: \(\int_{a}^{b} \frac{\log x}{x} d x\)
Answer:

Question 16.
Find the differential equation of the curve y = Ae^x + Be^-x; where A and B are constant.
Answer:
y = Ae^x + Be^-x
Differentiating both side w.r.t. x, we get
\(\frac{d y}{d x}\) = Ae^x + Be^-x
Again, differentiating w.r.t we get

or, \(\frac{d^{2} y}{d x^{2}}-y=0\) which is required, differential equation.

Question 17.
Find the particular solution of the differential equation \(\frac{d y}{d x}\) = ytanx when y = 1 if x = 0
Answer:

⇒ logy = -logcos x+ logC
⇒ log y + logcosx = log C
⇒ log (ycosx) = logC ⇒ ycosx = C …….(1)
Now, putting y= I and x = 0 in (1), we get
cos 0 = C ⇒ C = 1 ∴ y cos x = 1
y = \(\frac{1}{\cos x}\) ⇒ y = sec x

Question 18.
Find the unit vector in the direction of the vector \(\overrightarrow{\mathrm{a}}=2 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}+\hat{\mathrm{k}}\)
Answer:

Question 19.
If \(\overrightarrow{\mathrm{a}}=2 \hat{\mathrm{i}}+\hat{\mathrm{j}}+3 \hat{\mathrm{k}}\) and \(\overrightarrow{\mathbf{b}}=3 \hat{\mathbf{i}}+5 \hat{\mathbf{j}}-2 \hat{\mathbf{k}}\) then find the \(|\overrightarrow{\mathrm{a}} \times \overrightarrow{\mathrm{b}}|\)
Answer:

Question 20.
Find the equation of the planes parallel to the plane dr -3y + 2z + 9 = 0 and at distance 5 from the origin.
Answer:
Let the plane 6x – 3y + 2z + k = 0 is the parallel, to the plane 6x – 3y + 2z + 9 = 0. Now, the distance of plane 6x – 3y + 2z + 9 = 0 from the origin is

Thus the plane is 6x – 3y + 2k ± 35 = 0

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

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

Question 23.
Verify the continuity of the function f(x) = 2x² – 1 at x = 3.
Answer:

Question 24.
The radius of a circle is increasing at the rate of 0.7 cm/s. What is the rate of increase of its circumference when r = 4.9 cm ?
Answer:
Let c and r be the circumference and radius of circle. Then

Question 25.
Find the slope of the tangent to the curvey = x³ – x + 1 at the point whose x-co-ordinate is 2.
Answer:
Given the curve y = x³ – x + 1

Long Answer Type Questions

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

Question 26.
Prove that of all the rectangles inseribed in a given circle the square has the maximum area.
Answer:
Let ABCD be a rectangle inscribed in a given circle of centre O and radius r.
Let AB = 2x and BC = 2y,
∴∆ AOAM be a right angled triangle. Then
OA² = AM² + OM²
or, a² = x² + y²



Hence area is maximum when x = y
or, 2x = 2y Thus the rectangle is square.

Question 27.
Verify Lagrange’s mean value theorem when the function f(x) = (x – 1) (x – 2) (x – 3) in the interval [0,4].
Answer:
The given function, f(x) = (x – 1)(x – 2)(x – 3) in interval [0,4]
⇒ f(x) = (x² -x -2x + 2) (x – 3)
⇒ f(x) = (x² – 3x + 2) (x – 3) = x³ – 3x² + 2x – 3x² + 9x – 6
⇒ f(x) = x³ -6x² + 11x – 6
Since f(x) is a polynomial function and polynomial function is continuous, i.e. f(x) is continuous in [0, 4]
Also, f'(x) = 3x² – 2x +11, exists in interval ]0, 4[.
So, f(x) is differentiable in ]0,4[. Thus Lagrange’s theorem are satisfied
∴ c ∈] 0,4 [ exist.

Clearly, the both value of c lie between ] 0, 4 [. Thus theorem is verified.

Question 28.
Find area enclosed by the ellipse \(\frac{x^{2}}{9}+\frac{y^{2}}{4}=1\)
Answer:
We have, The equation of ellipse

Putting x = 3sinθ ⇒ dx = 3cosθ. Also,
when x = 0, then θ = 0 and when A = 3 then θ = π/2
∴ Required area of the ellipse

Question 29.
Evaluate: \(\int_{0}^{\pi / 2} \log \sin x d x\)
Answer:

Question 30.
Prove that
\(\overrightarrow{[a} \times \vec{b}, \vec{b} \times \vec{c}, \vec{c} \times \vec{a}]=[\vec{a}, \vec{b}, \vec{c}]^{2}\)
Answer:

Question 31.
Find the co-ordinates of the foot of the perpendicular drawn from the origin to the plane 2r – 3y + 4z – 6 = 0.
Answer:
Let the co-ordinates of the foot of the perpendicular P from the origin to the plane is P (x₁, y₁, z₁).
Then the direction ratios of the line OP are x₁y₁, z₁.
Now the direction ratio of the plane is 2, – 3, 4. So direction cosines are

Now, since the direction cosines and direction ratios of the line are proportional. Then



Thus the co-ordinates of foot of perpendicular is

Question 32.
Solve the LPP: Minimize Z = – 3x + 4x
under the constraints x + 2y ≤ 8, 3x + 2y ≤ 12, x ≥ 0, y ≥ 0.
Answer:
Minimize Z = -3x + 4. under the costraints
A + 2y ≤ 8 ⇒ x + 2y = 8 …..(1)
3x + 2y ≤ 12 ⇒ 3x + 2y = 12 …(2)
x ≥ 0, y ≥ 0 ⇒ x = 0, y = 0 …(3)

First of all draw the graph of the equations (1) to (3) corresponds to the inequations. It is clear from figure, that (1) and (2) are intersect each other at the point (2,3). So, we get a feasible region OABC, which is bounded. The co-ordinates of the corner points of the feasible region are 0(0, 0) A(4,0), B(2, 3) and C (0, 4). Lastly, applying corner point method to find the value of the objective function Z are as follows :

It is clear from the above table that the minimum value of Z at the point (4,0) is – 12. Thus the minimum value of Z is -12

Question 33.
A furniture dealer deals in only two items tables and chairs. He has Rs. 5000/- to invest and a space to store at most 60 pices. A table costs him Rs. 250 and a chair Rs. 50. He can sell a table at a profit to Rs. 50 and a chair at a profit of Rs. 15. Assuming that he can sell all the items that he buys how should he invest his money in order that he may maximize his profit.
Answer:
Let x and y represents tables and chairs respectively. Now, by question costs of x tables = 250 x and the chair = 50y ∴ Total costs (250x + 50y)
Since the dealer has invest Rs. 5000
∴ 250x + 50v ≤ 5000 =>5y + y ≤ 100
Again, the dealer has a space to store at most 60, so
x + y ≤ 60
Also, non-negative constraints : x ≥ 0, y ≥ 0.
Further, profit from x table = 50.v and y chair = 15y
Objective Function Z = 50x + 15y
So. the mathematical form of the problem are as follows
Maximize Z = 50x + 15y
Subject to constraints 5x + y ≤ 100 ⇒ 5x + y = 100 .. .(1)
v + y ≤ 60 ⇒ x + y = 60 .. .(2)
x ≥ 0, y ≥ 0 ⇒  x = 0, y = 0 …(3)
First of all draw the graph of equations (1) to (3) corresponds to inequations. On joining the points (20, 0),

(0,100) and (60,0), (0,60) we get two straight line, which intersects at the point (10, 50). The point of intersection (10, 50) can be obtained from solving equations (1) and (2). It is clear from figure OABC be the feasible region, which is bounded. Lastly, by the using comer points of feasible region 0(0, 0), A(20,0), B(10,50) and C(0, 60) to find the maximum values of Z :

It is clear from the table that the maximum value of Z is Rs. 1250. Thus the maximum profit to the dealer for buying 10 tables and 50 chairs.

Bihar Board 12th Chemistry Model Papers

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

Time : 3 Hours 15 Min
Full Marks: 70

Instructions for the candidates

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

Objective Type Questions

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

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

Question 2.
Study the figure of a solid given below depicting the arrangement of particles. Which is the most appropriate term used for the figure ?

(a) Isotropy
(b) Anisotropy
(c) Irregular
(d) Amorphous nature
Answer:
(b) Anisotropy

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

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

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

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

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

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

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

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

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

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

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

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

Question 15.
Which of the following is not the correct name of the formula of the ore given with it ?
(a) MgSO₄.7H₂O – Epsom salt
(b) CuCO₃.Cu(OH)₂ – Malachite
(c) KAlSi₃O_g– Feldspar
(d) MgCl₂.6H₂O – Dolomite
Answer:
(d) MgCl₂.6H₂O – Dolomite

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

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

Question 18.
General electronic configuration of transition metals is ………………….
(a) (n-1)d^1_10ns²
(b) nd^wns²
(c) (n-1)d¹⁰ns²
(d) (n-1)d1⁵ns²
Answer:
(a) (n-1)d^1_10ns²

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

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

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

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

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

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

Question 25.
IUPAC name of

(a) 3-propylbutan-1-o1
(b) 2-ethylpentan-1-o1
(c) 3-methyl hydroxyhexane
(d) 2-ethyl-2-propyl ethanol
Answer:
(b) 2-ethylpentan-1-o1

Question 26.
Which of the following structures is not correctly matched ?

Answer:
(c)

Question 27.
Which of the following carbonyl compounds is most , polar ?

Answer:
(d)

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

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

Question 30.
The general formula of carbohydrates is……………….
(a) C_nH_2n+10
(b) C_nH_2nO
(c) C_n(H₂O)_n
(d)C_n(H₂O)_2n
Answer:
(c) C_n(H₂O)_n

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

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

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

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

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

Non-Objective Type Questions

Short Answer Type Questions

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

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

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

Lyophilic Colloids :

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

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

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

Question 4.
How would you convert
(a) aniline to bromobenzene
(b) ethanal to methanamine ?
Answer:
(a) Aniline to Bromobenzene :

(b) Ethanol to methanamine :

Question 5.
Given reasons for the following :
(a) Formic acid is stronger than acetic acid.
(b) Aniline is less basic than methylamine.
Answer:
(a) Formic acid is stronger than acetic acid – In every acid its acidity depends upon donation of proton from the solution .

If the value of Ka is maximum, the acidity will be max^m-
HCOOH → Ka – 1.77 x 10⁵
CH₃COOH → Ka- 1.75 x 10⁵
So, by the above equations it is clear that formic acid is more acidic than acetic acid.

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

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

(b) Phenol is more acidic than alcohol-Phenol is generally a weak acid, but it has acidic property because it gives phenoscide ion in the solution.

In the above reaction the negative charge gives stability to the phenoscide ion.

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

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

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

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

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

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

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

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

Absortion :

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

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

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

Frenkel defect:

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

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

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

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

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

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

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

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

• CuFe S₂
• Cu₂ O

Long Answer Type Questions

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

Question 19.
(a) A first order reaction is 75% completed in 60 min. Find the half-life period of the reaction.
(b) Given one example each of zero order and first order reactions.
Answer:
(a) We know that half life period \(t_{1 / 2}=\frac{0.693}{K}\)
Also, the first order expression is 2.303

Now, by putting the values of K in above equation.

(b) Examples of Zero-order reaction

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

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

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

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

(ii) The oxoanions of metals have co-valent mature in which oxygen is involved in the multiple bonding with the metal atom. This is responsible for the high oxidation state of the metal in oxoamine. For example-The elements Mn exibibits +7 oxidation state in permaganate ion (MnO₄^_)

Question 21.
Write IUPAC names of the following :
(i) CH₃CONH₂
(ii) (CH₃)₂CHCH₂COCl
(iii) CH₃ – O – C₂H₅
(iv) Ch₃CH₂CN

Answer:
(i) CH₃ CONH₂ → Ethanamide
(ii) (CH₃)₂ CHCH₂ CoCl -3-Methyl butanoil Chloride.
(iii) CH₃ – O – C₂H₅ – Methoxy ethane.
(iv) CH₃CH₂CN — Ethyl isocyanide

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

There are following two types of polarization.

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

(b) Condensation Polymerization- Condensation Polymers are formed by repeated condensation reaction between two bifunctional or trifunctional monomer units usually with the elimination of small molecules like water, alcohol, ammonia, Carbondioxide, hydrogen chloride, etc. and process by which condensation Polymers are formed is called condensation polymerization.

Question 23.
A element A (atomic mass = 100) having 100 structure has unit cell edge length of 400 pm. Calculate the density of A and number of unit cells in 10 cm of A.
Answer:
a (edge length) = 400 pm
N_a = 6.02 x 10²³
M = 100 gm / mole.

Question 24.
Write the following giving chemical equations :
(i) Carbylamine reaction
(ii) Wurtz reaction.
(iii) Nitration of benzene
Answer:
(i) Carbylamine reaction – Chloroform when heated with primary amine in presence of alcoholic KOH. forms a derivative called isocyanide.

(ii) Wurtz reaction – When two moles of alkyl halide is heated with Na in the presence of ether goes higher alkane.

(iii) In the presence of concentration H₂SO₄ benzenes reacts with cone HNO₃ and it is found into benzene.

Bihar Board 12th Chemistry Model Papers

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

Time : 3 Hours 15 Min
Full Marks: 70

Instructions for the candidates

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

Objective Type Questions

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

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

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

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

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

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

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

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

Question 8.
In a cell reaction,

If the concentration of Cu²⁺ ions is doubled then Ep_ell will be
(a) doubled
(b) halved
(c) increased by four times
(d) unchanged
Answer:
(d) unchanged

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

Question 10.
In a reaction 2X → Y, the concentration of X decreases from 3.0 moles/litre to 2.0 moles/litre in 5 minutes. The rate of reaction is …………
(a) 0.1 mol L^-1 min ¹
(b) 5 mol L^-1 min^-1
(c) 1 mol L^_1 min^-1
(d) 0.5 mol L^-1 min^-1
Answer:
(a) 0.1 mol L^-1 min ¹

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

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

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

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

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

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

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

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

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

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

Question 21.
Which of the following is a tridentate ligand ?
(a) EDTA^4-
(b) (COO)₂^2-
(c) dien
(d)  NO^–₂
Answer:
(c) dien

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

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

Answer:
(c)

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

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

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

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

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

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

Question 30.

(a) 2-Iodoheptane
(b) Heptane-2-ol
(c) 2-lodohexane
(d) Heptanoic acid
Answer:
(d) Heptanoic acid

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

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

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

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

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

Short Answer Type Questions

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

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

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

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

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

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

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

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

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

Question 8.
How will you convert Aniline into Benzoic acid ?
Answer:

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

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

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

Question 12.
(a) Write the IUPAC name of the following compound :
Answer:

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

Question 13.
If 20 g of calcium carbonate is added to a solution containing 20 g of HCl. What substances will be present when the reaction is over and what quantity of each of them will be present there?
Answer:

Thus, HCl will be present when the reaction is over. Rest amount of HCl = 20 – 14.8 = 0.56 g.

Question 14.
Write chemical reaction to obtain the following :
(i) Methane to chloroform
(ii) Chloroform to ethyne.
Answer:

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

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

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

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

Question 18.
Give I.U.P.A.C. names of the following :

Answer:
(a) Butane-1,4 dioic acid
(b) 2-hydroxy propan-1- oic acid.

Long Answer Type Questions

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

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

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

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

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

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

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

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

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

• sea weeds
• chile salt puter
• Natural brine.

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

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

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

Iodine obtained by this method contains CI₂ and Br₂ as impurifies. It is treted with KI to obtained pure Iodine

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

(ii) Sulphur trioxide is dissolved in 98% sulphuric acid, forms oleum.

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

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

(b)

• KCI, Br₂
• HIOj, HCl
• NaCl, NaClO₃

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

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

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

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

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

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

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

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

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

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

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

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

(iii) Reduction: ZnO thus formed as a result of roasting or calcination is reduced by carbon. As a result at reduction Zn metal in molten state is formed.

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

Bihar Board 12th Economics Model Papers

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

Time : 3 Hour 15 Min
Full Marks : 100

Instructions

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

Objective Type Questions

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Non-Objective Type Questions

Short Answer Type Questions

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

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

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

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

Percentage incress in all factors

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

Question 3.
Where is the equilibrium price determined ?
Answer:
Commodity Price : Demand-Supply Equilibrium : Buyer wants to give the least price while the seller wants to take the maximum price of the commodity. Bargaining takes price between both the parties and at last, the price of the commodity is determined at the price where both demand for and supply of the commodity become equal. This price is called equilibrium price.

In following Fig. price determined of the commodity by demand and supply forces has been shown. Demand curve DD and supply curve is cuts each other at point E where price OP is determined. This price OP (or EQ) shows the equilibrium price.

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

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

Macro Economics :

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Commercial Bank :

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

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

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

Question 15.
What is the shape of demand curve of a firm in perfect competition ?
Answer:

When a demand schedule is graphically represented, we get a demand curve. It shows the inverse relationship between price and quantity demanded. Due to this inverse relationship, demand curve slopes downward from left to right. It shows that higher the price, lower will be the quantity demanded and vice versa.

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

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

Balance of payments :

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

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

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

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

Question 19.
By which percentage method elasticity of demand is measured ?
Answer:
Percentage method :

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

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

1. Extention of supply
2. Contraction supply.

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

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

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

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

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

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

Long Answer Type Questions

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Planned Economy :

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

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

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

It can be measured as follow :

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

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

Definitions :

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

Following are the causes of supply of commodity :

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

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

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

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

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

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

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

Thrid Step : Calculation of Net Factor Income from Abroad : The third and final step in the estimation of national income is to estimate the net factor income earned from abroad and add it to the net domestic product at factor cost. This gives us the national income.
In shot, NNP_FC = NDP_FC + NFIA

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

(I) Other Functions :

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

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

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