Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is(a) same as the same force law is involved in the two experiments. (b) less for the case of a positron, as the positron moves away more rapidly and the force on it weakens. (c) more for the case of a positron, as the positron moves away a larger distance. (d) same as the work done by charged particle on the stationary proton.

Answer»

(c) more for the case of a positron, as the positron moves away a larger distance. 

2.

Estimate the amount of energy released in the nuclear fusion reaction:21H + 21H → 32 He + n[21H: deuterium, 32He; Isotope of helium], Given that M [32He] = 3.0160 u, M[n] = 1.000 87 u and M[21H = 2.014 u, where 1u = 1.661 x 10-27 kg]. Express your answer in units of MeV.

Answer»

Mass of reactants = 2 x 2.0141 u = 4.0282 u

Mass of products = 3.0160 u + 1.0087 u = 4.02247 u

Mass defect = Δm = (4.0282 - 4.0247) u

= 3.5 x 10-3 u

= 3.5 x 10-3 x 1.661 x 10-27 kg

Energy released = (Loss of mass x c2) J

= 3.5 x 10-3 x 1.661 x 10-27 x (3 x 108)2

= {0.5232 x 10-12}/{1.6 x 10-13} = 3.27 MeV

3.

If a1, a2, ....., a50 are in G.P., then \(\frac{a_1-a_3+a_5-....+a_{49}}{a_2-a_4+a_5-....+a_{50}}\) is equal to(a) 0 (b) 1 (c) \(\frac{a_1}{a_2}\)(d) \(\frac{a_1}{a_{50}}\)

Answer»

(c) \(\frac{a_1}{a_2}\)

Let the first term of the G.P. be a and common ratio r. Then,

\(\frac{a_1-a_3+a_5-....+a_{49}}{a_2-a_4+a_5-....+a_{50}}\) = \(\frac{a-ar^2+ar^4-....+ar^{48}}{ar-ar^3+ar^5-....+ar^{49}}\)

= \(\frac{a(1-r^2+r^4-....+r^{48})}{ar(1-r^2+r^4-....+r^{48})}\) = \(\frac{a}{ar}\) = \(\frac{a_1}{a_2}\).

4.

f(x) = sin x - kx is decreasing for all x ∉ R, whenA. k < 1B. k ≤ 1C. k > 1D. k ≥ 1

Answer»

Answer is : D. k ≥ 1

f(x) = sin x - kx

f’(x) = cos x – k

∴ f decreases, if f’(x) ≤ 0

⇒ cos x – k ≤ 0

⇒ cos x ≤ k

So, for decreasing k ≥ 1.

5.

A. Say whether the following statements are True or False. Write ‘T’ for true and ‘F’ for false: 1. Environmental purity is needed for total health. 2. The purity of society brings about harmony and unity. 3. Drona never summoned the Pandavas and Kauravas for any test. 4. Yudhishthira found everyone to be pious and pure. 5. Purity has the power to transform even the villains and murderers. 6. Pavaharibaba offered the rest of the food also to the thief. 7. Proud Gautam was humbled by the purity of a simple house-wife and an ordinary man. 8. Nurturing can change the behaviour of human beings as well as animals.

Answer»

1. True 

2.True 

3. False 

4. True 

5. True 

6. True 

7. True 

8. True

6.

Write the importance of purity of the environment. पर्यावरण की पवित्रता का महत्व लिखिए।

Answer»

The purity of the environment is very essential for overall health. The environment is a quite wide system including air, water, food, society and everything that surrounds us. We need a pure environment for physical and mental health.

सम्पूर्ण स्वास्थ्य के लिए पर्यावरण की पवित्रता-शुद्धता अति आवश्यक है। वायु, जल, भोजन, समाज और हमें चारों ओर से आवृत्त किये हुए हर वस्तु को सम्मिलित कर पर्यावरण अति विस्तृत तंत्र है। शारीरिक और मानसिक स्वास्थ्य के लिए हमें पवित्र पर्यावरण की आवश्यकता है।

7.

What is the importance of pure atmosphere? पवित्र वातावरण का क्या महत्व है?

Answer»

There is great importance of pure atmosphere in making a man physically and mentally pure. One who is brought up in pure atmosphere becomes pure. Impure atmosphere contaminates even a pure man.

व्यक्ति को शारीरिक और मानसिक रूप से शुद्ध-पवित्र-बनाने में पवित्र वातावरण का बहुत महत्व है। जिसका पालन-पोषण पवित्र वातावरण में होता है, वह पवित्र हो जाता है। अपवित्र वातावरण पवित्र मनुष्य को भी अपवित्र कर देता है।

8.

Why are Samskaras important in our life? संस्कार हमारे जीवन में महत्त्वपूर्ण क्यों होते हैं?

Answer»

Samskaras are important in our life because these wash off our impurities and bad habits and put the base on which a wall of virtues could be erected. There are some weaknesses present even in a very good boy or girl. Samskaras are in fact psychological and religious treatment to root out the weaknesses and to implant good thoughts and views. When a parrot if trained properly can imitate the human voice, then why can a human child not become more perfect and efficient through Samskaras? Therefore our forefathers have designed sixteen Samskaras to make a man a true man, a pure man. It is a fact that virtues enable a person to live a quality life. And qualities of life come through psychological and religious treatment. That’s why Samskaras are important in our life. 

संस्कार हमारे जीवन में महत्त्वपूर्ण हैं क्योंकि ये हमारी अपवित्रताओं और बुरी आदतों को धो डालते हैं और ऐसे आधार को रखते हैं जिस पर सद्गुणों की दीवार खड़ी की जा सके। एक बहुत अच्छे लड़के या लड़की में भी कुछ कमियाँ होती हैं। संस्कार यथार्थ में उन कमियों को दूर करने एवं अच्छे विचारों को स्थापित करने के मनोवैज्ञानिक एवं धार्मिक उपचार हैं। जब एक तोता यदि भली-भाँति प्रशिक्षित हो जाये तो एक मनुष्य की आवाज़ की नकल कर सकता है तो संस्कारित होकर एक मनुष्य का बालक और अधिक योग्य और सक्षम क्यों नहीं हो सकता? इसीलिए हमारे पूर्वजों ने मनुष्य को सच्चा मनुष्य, पवित्र मनुष्य बनाने के लिए सोलह संस्कारों की रूपरेखा बनाई है। यह एक तथ्य है कि सद्गुण ही मनुष्य को उत्कृष्ट जीवन जीने हेतु सक्षम बनाते हैं । और जीवन के गुण मनोवैज्ञानिक और धार्मिक उपचारों के माध्यम से ही पनपते हैं। यही कारण है कि संस्कार हमारे जीवन में अति महत्त्वपूर्ण हैं।

9.

Describe the significance of the crane episode. सारस वाली घटना के महत्व का वर्णन कीजिए।

Answer»

The crane episode is related to Gautam rishi who wanted to obtain certain powers through tapasya. He observed rigorous austerities for a long period. One day the rishi was having a holy dip in the river when the droppings of a crane, sitting among the branches of a tree, fell on his head. The rishi got angry and killed the bird with his angry gaze. This event created pride in Gautam. After this, he went to a nearby village to have alms. When the house lady got late to come out, Gautam became angry. At this, she said that she was not a crane. Hearing this Gautam got surprised and humbled. Then she sent him to a man who was also pure and simple. That lady and that pious man rooted out Gautam’s pride and since then Rishi Gautam became simple and gentle.

 सारस वाली घटना गौतम ऋषि से सम्बन्धित है जो तपस्या द्वारा कुछ शक्तियाँ प्राप्त करना चाहते थे। उन्होंने एक लम्बी अवधि तक कठोर संयम (सदाचार) का पालन किया। ऋषि एक दिन नदी में पवित्र स्नान कर रहे थे कि पेड़ की शाखाओं पर बैठे हुए एक सारस की बीट ऋषि के सिर पर गिर गई । ऋषि नाराज हो गए। और उन्होंने अपने क्रोधपूर्ण घूरने (एकटक दृष्टि) से पक्षी को मार डाला। इस घटना ने गौतम में घमण्ड पैदा कर दिया। इसके उपरान्त वह समीप के ग्राम में भिक्षा के लिए गये। जब गृहस्वामिनी को आने में देर हो गई तो गौतम नाराज हो गये। इस पर उसने कहा कि वह सारस नहीं है। यह सुनकर गौतम आश्चर्यचकित और अपमानित सा हो गये। तब उस स्त्री ने गौतम को एक व्यक्ति के पास भेजा जो पवित्र और साधारण था। उस स्त्री और उस पवित्र व्यक्ति ने गौतम के घमण्ड को नष्ट कर दिया और तब से ऋषि गौतम सरल और विनम्र हो गये।

10.

What is injurious to health and why? स्वास्थ्य के लिए क्या हानिकारक है और क्यों?

Answer»

Impurity is injurious to health. It is because impurity creates diseases and toxins inside the body and mind. Everyone hates impurity because complications arise from it and it gradually makes us weak physically and mentally.

अपवित्रता या अशुद्धि स्वास्थ्य के लिए हानिकारक है। ऐसा इसलिए है क्योंकि अपवित्रता हमारे शरीर और मन के अन्दर रोग और विषैले तत्व पैदा करती है। अपवित्रता से प्रत्येक व्यक्ति घृणा करता है क्योंकि इससे जटिलताएँ उत्पन्न होती हैं और यह हमें धीरे-धीरे शरीर और मन से कमजोर बनाती है।

11.

“The man was bright with purity”. How does the author bring this out? “वह आदमी पवित्रता से प्रकाशित था।” लेखक इस तथ्य को कैसे स्पष्ट करता है?

Answer»

The author says that the test of genuine purity is in its metamorphosing ability. The man seemed neither well educated nor a saint. But Rishi Gautam was completely transformed in his presence. So the man was bright with purity. 

लेखक कहता है कि यथार्थ पवित्रता की परीक्षा उसकी परिवर्तन करने की क्षमता से होती है। वह आदमी न तो सुशिक्षित प्रतीत होता था और न कोई सन्त! लेकिन उसकी उपस्थिति में ऋषि गौतम पूर्णतः बदल गए। इसलिए वह आदमी पवित्रता से प्रकाशित था।

12.

In which areas do we need purity? हमें किन क्षेत्रों में पवित्रता की आवश्यकता होती है?

Answer»

We need purity in all fields of life. Without purity, everything is useless and ugly. We need pure food, pure water, pure air, pure environment, pure love and heart, pure society, pure knowledge, pure thoughts, pure mind and pure speech.

हमें जीवन के हर क्षेत्र में पवित्रता की आवश्यकता होती है। पवित्रता से रहित हर वस्तु बेकार और कुरूप है। हमें पवित्र भोजन, पवित्र जल, पवित्र वायु, पवित्र वातावरण, पवित्र प्रेम और हृदय, पवित्र समाज, पवित्र ज्ञान, पवित्र विचार, पवित्र मन और पवित्र वाणी की आवश्यकता है।

13.

What are the merits of purity?पवित्रता के गुण क्या हैं?

Answer»

Purity is a divine gift for mankind on this earth. The purity of the body promotes our physical health. The purity of thought promotes our morality and purity of mind provides us with mental peace. The purity of heart promotes unselfish love for humanity. The purity of action develops a sincere and unselfish service. The purity of society develops the spirit of harmonious unity. The purity of the environment provides us with soul-elevating serenity. The purity of mind makes our vision, words and deeds pure. Purity makes a man so great and powerful that he can change a bad one into a good man. Purity provides us spiritual power and lightens our brain. Purity is the key to all success. It establishes harmony and unity in social life. Purity itself has the power to make people pure.

पवित्रता इस पृथ्वी पर मानवता के लिए एक दैवी उपहार है। शरीर की पवित्रता हमारे शारीरिक स्वास्थ्य को बढ़ाती है। विचारों की पवित्रता हमारी नैतिकता को बढ़ाती है और मन की पवित्रता हमें मानसिक शान्ति प्रदान करती है। हृदय की पवित्रता मानवता के लिए निस्वार्थ प्रेम को बढ़ावा देती है। कार्य की पवित्रता सच्ची और निस्वार्थ सेवा का विकास करती है। समाज की पवित्रता सामंजस्यपूर्ण एकता की भावना का विकास करती है। पर्यावरण की पवित्रता हमें आत्मोत्थान हेतु शान्ति प्रदान करती है। मस्तिष्क की पवित्रता हमारी दृष्टि, वाणी तथा कार्यों को पवित्र बनाती है। पवित्रता किसी व्यक्ति को इतना महान और शक्तिशाली बना देती है कि वह एक बुरे आदमी को अच्छे आदमी में बदल सकता है। पवित्रता हमें आध्यात्मिक शक्ति प्रदान करती है और हमारे मस्तिष्क को प्रकाशित करती है। पवित्रता सभी सफलताओं की कुंजी है। यह सामाजिक जीवन में सामंजस्य एवं एकता स्थापित करती है। पवित्रता में स्वयं ही लोगों को पवित्र बनाने की शक्ति होती है।

14.

‘As is the mind so is the vision.’ Explain it with reference to the Mahabharata episode cited by the writer. ‘जिस प्रकार का मन होता है, वैसी ही दृष्टि हो जाती है।’ लेखक के द्वारा उधृत महाभारत की घटना के संदर्भ में इस कथन की व्याख्या कीजिए।

Answer»

Pandavas, Yudhishthira, was asked to fetch an evil man and similarly, the eldest of the Kauravas, Duryodhana, was asked to fetch a good man from the society of Hasthinapur. Yudhishthira being pure hearted, found everyone to be pious and pure and Duryodhana being impure minded, found everyone evil and impure. Therefore neither Yudhishthira could find out an evil man nor could Duryodhana find out a good man from the society of Hasthinapur. Both of them failed in their mission. The proverb, ‘as is the mind, so is the vision’ holds good in both the cases. All things are good to the good and all things are bad to the bad.

एक बार द्रोणाचार्य ने पाण्डवों और कौरवों को परीक्षा के लिए बुलाया। पाण्डवों में सबसे बड़े युधिष्ठिर को एक बुरे व्यक्ति को व कौरवों में सबसे बड़े दुर्योधन को एक अच्छे व्यक्ति को हस्तिनापुर के समाज में से ढूँढ़कर लाने को कहा गया। युधिष्ठिर ने शुद्ध-हृदय व्यक्ति होने के कारण सभी को पवित्र समझा। इसी तरह से दुर्योधन ने अपवित्र (बुरे) विचारों वाला व्यक्ति होने के कारण सबको खराब समझा। इसलिए न तो युधिष्ठिर हस्तिनापुर के समाज से एक बुरा आदमी खोज सका और न दुर्योधन एक अच्छा आदमी खोज सका। दोनों ही अपने-अपने लक्ष्य में असफल रहे। जिस प्रकार का मन होता है, वैसी ही दृष्टि हो जाती है, यह कहावत दोनों ही के मामलों में खरी उतरती है। अच्छों के लिए सभी चीजें अच्छी होती हैं और बुरों के लिए सब कुछ बुरा ही हुआ करता है।

15.

What do we want for good health? हम अच्छे स्वास्थ्य के लिए क्या चाहते हैं?

Answer»

For good health, we want pure food, pure water, pure air, pure surroundings and environment, pure love and care, and pure society. It is because purity promotes health and strengthens us. 

अच्छे स्वास्थ्य के लिए हम पवित्र भोजन, पवित्र जल, पवित्र वायु, पवित्र वातावरण, पवित्र प्रेम और देखभाल तथा पवित्र समाज चाहते हैं। ऐसा इसलिए है, क्योंकि पवित्रता स्वास्थ्य को बढ़ाने में मदद करती है और हमें मजबूत बनाती है।

16.

How does bringing up make all the difference in shaping lives? Illustrate with the help of the parrots’ episode. पालन-पोषण किस प्रकार जीवन को आकृति देने में अन्तर पैदा कर देता है? तोतों वाली घटना की सहायता से स्पष्ट कीजिए।

Answer»

The method of bringing up and the atmosphere available around greatly influence the kid’s life. One who is brought up in a peaceful and civilized atmosphere becomes gentle and civilized while the other who is brought up in an uncivilized atmosphere becomes uncivilized. It can be well understood with the help of parrot episode. There were two parrots born together from the same mother. One of them was taken away by a hunter while the other one was taken by a scholar. One who was brought up by the hunter learnt the vulgar slang while the one brought up by the scholar learnt to speak with softness, refinement and culture. This was due to the way of bringing up and the atmosphere available around. It is a crystal clear fact that Samskaras and environment influence people very much. 

पालन-पोषण करने की विधि एवं आस-पास का वातावरण बच्चे के जीवन को बहुत अधिक प्रभावित करते हैं। वह जिसकी पालन-पोषण शान्त और सभ्य वातावरण में होता है, सभ्य और विनम्र बन जाता है जबकि कोई दूसरा जिसका पालन-पोषण असभ्य वातावरण में होता है, असभ्य बन जाता है। इसे तोतों वाली घटना से अच्छी प्रकार समझा जा सकता है। एक ही माँ से एक साथ जन्मे दो तोते थे। उनमें से एक को एक शिकारी ले गया जबकि दूसरे को एक विद्वान व्यक्ति ले गया। वह जिसका पालन-पोषण शिकारी ने किया, गन्दी और असभ्य भाषा बोलना सीख गया जबकि दूसरा जिसका पालन विद्वान के यहाँ हुआ, कोमलता, शिष्टता और सभ्यता के साथ बोलना सीख गया। यह सब उनके पालन-पोषण करने की विधि और आस-पास उपलब्ध वातावरण के कारण था। यह बात बिल्कुल स्पष्ट है कि व्यक्ति के ऊपर उसके संस्कारों और आस-पास के वातावरण का बहुत ही ज्यादा प्रभाव पड़ता है।

17.

How does ‘purity’ help a man?‘पवित्रता’ मनुष्य की किस प्रकार सहायता करती है?

Answer»

Purity is a divine gift for mankind. It can purify an impure person. Evils run away in the presence of purity as darkness disappears in the presence of the sunlight. Fools, villains and criminals become wise, gentle and obedient before a pure man.

पवित्रता मानवता के लिए एक दैवी उपहार है। यह एक अपवित्र मानव को पवित्र कर सकती है। जैसे सूर्य के प्रकाश में अंधकार गायब हो जाता है उसी प्रकार पवित्रता के सामने बुराइयाँ भाग जाती हैं। मूर्ख, दुष्ट व अपराधी प्रवृत्ति के लोग पवित्र आत्मा वाले व्यक्ति के सम्मुख बुद्धिमान, अच्छे और आज्ञाकारी व्यक्ति बन जाते है।

18.

Describe purity in different areas and their merits. विभिन्न क्षेत्रों में पवित्रता एवं उसके गुणों का वर्णन कीजिये।

Answer»

Purity is a divine gift for mankind on this earth. The purity of the body promotes our physical health. The purity of thought promotes our morality and purity of mind provides us with mental peace. The purity of heart promotes unselfish love for humanity. The purity of action develops a sincere and unselfish service. The purity of society develops the spirit of harmonious unity. The purity of the environment provides us with soul-elevating serenity. The purity of mind makes our vision, words and deeds pure. Purity makes a man so great and powerful that he can change a bad one into a good man. Purity provides us spiritual power and lightens our brain. Purity is the key to all success. It establishes harmony and unity in social life. Purity itself has the power to make people pure.

पवित्रता इस पृथ्वी पर मानवता के लिए एक दैवी उपहार है। शरीर की पवित्रता हमारे शारीरिक स्वास्थ्य को बढ़ाती है। विचारों की पवित्रता हमारी नैतिकता को बढ़ाती है और मन की पवित्रता हमें मानसिक शान्ति प्रदान करती है। हृदय की पवित्रता मानवता के लिए निस्वार्थ प्रेम को बढ़ावा देती है। कार्य की पवित्रता सच्ची और निस्वार्थ सेवा का विकास करती है। समाज की पवित्रता सामंजस्यपूर्ण एकता की भावना का विकास करती है। पर्यावरण की पवित्रता हमें आत्मोत्थान हेतु शान्ति प्रदान करती है। मस्तिष्क की पवित्रता हमारी दृष्टि, वाणी तथा कार्यों को पवित्र बनाती है। पवित्रता किसी व्यक्ति को इतना महान और शक्तिशाली बना देती है कि वह एक बुरे आदमी को अच्छे आदमी में बदल सकता है। पवित्रता हमें आध्यात्मिक शक्ति प्रदान करती है और हमारे मस्तिष्क को प्रकाशित करती है। पवित्रता सभी सफलताओं की कुंजी है। यह सामाजिक जीवन में सामंजस्य एवं एकता स्थापित करती है। पवित्रता में स्वयं ही लोगों को पवित्र बनाने की शक्ति होती है।

19.

Justify the title of the lesson, ‘Purity is Power’. ‘पवित्रता ही शक्ति है’ पाठ के शीर्षक की सार्थकता सिद्ध कीजिए।

Answer»

‘Purity is Power’ is a quite appropriate title of this lesson. The total theme of the lesson moves around the kinds and importance of purity. In the beginning, the lesson explains the types of purity. The purity of body, purity of thoughts, purity of words, purity of mind, purity of environment etc. are different kinds of purities. Along with the types of purity, the effects of these different purities have been mentioned. Apart from this, it has been illustrated with examples from epics that what happens when a person becomes pure in mind, words and deeds. A pure person becomes so powerful that he can transform a bad man into a good one. All these things signify that the title of this lesson ‘Purity is Power’ is quite appropriate. Purity strengthens soul and body. 

‘पवित्रता ही शक्ति है’ पाठ का यह शीर्षक बिल्कुल उचित है। पाठ की सम्पूर्ण कथावस्तु पवित्रता के प्रकार और महत्व के आस-पास घूमती है। सर्वप्रथम यह बताया गया है कि पवित्रता कितने प्रकार की होती है। शरीर की पवित्रता, विचारों की पवित्रता, वाणी की पवित्रता, मन की पवित्रता, पर्यावरण की पवित्रता आदि अनेक प्रकार पवित्रताएँ हैं। पवित्रता के प्रकारों के साथ-साथ इन विभिन्न प्रकार की पवित्रताओं के प्रभावों या परिणामों को बताया गया है। इसके अलावा, महाकाव्यों से उदाहरण लेकर यह स्पष्ट किया गया है कि जब कोई व्यक्ति मन, वाणी और कर्म से पवित्र हो जाता है तो क्या होता है। एक पवित्र व्यक्ति इतना शक्तिशाली हो जाता है कि वह एक बुरे व्यक्ति को अच्छे व्यक्ति में बदल सकता है। ये सभी चीजें यह स्पष्ट करती हैं कि इस पाठ का शीर्षक ‘पवित्रता ही शक्ति है’ बिल्कुल उचित है। पवित्रता आत्मा और शरीर दोनों को शक्तिशाली बनाती है।

20.

I have seen her footprints going up the hill.

Answer»

This sentence was said by Abbu Miyan to Govinda.

21.

“Hey Abbu Miyan! Looking sad ? Why are you sitting alone today? Where is your darling Kalua ?” Govinda was worried. “Perhaps, I have lost her. I have seen her footprints going up the hill. That devil must have killed her.”1. Why was Govinda worried ?2. Where did Kalua go ?3. ‘I have lost her.’ Why did Abbu Miyan say this ?

Answer»

1. Govinda was worried because Abbu Miyan was sitting alone and looking sad.

2. Kalua went up the hill.

3. Abbu Miyan said this because he saw Kalua’s footprints going up the hill and so the devil there must have killed her.

22.

After some days Abbu Miyan bought another goat. This new one was pretty, white as snow, had two little horns and a pair of lovely bright red eyes. “I will call you Chandani,” caressing her soft fur he said.1. Describe the new goat bought by Abbu Miyan.2. What did Abbu Khan call the goat ?

Answer»

1. The new goat was pretty, white as snow, had two little horns and a pair of lovely bright red eyes.

2. Abbu Khan called the goat Chandani.

23.

Abbu Miyan said this because he saw Kalua’s footprints going up the hill and so the devil there must have killed her.1. Why was Abbu Khan in tears ?2. What did Abbu Khan give Kalua to eat ?

Answer»

1. Abbu Khan was in tears because Kalua had broken the string and disappeared in the night.

2. Abbu Khan gave Kalua green, juicy grass and tasty grains to eat.

24.

A metal piece of 50 g specific heat 0.6 cal/gºC initially at 120ºC is dropped in 1.6 kg of water at 25ºC. Find the final temperature or mixture.

Answer»

m1c1 (θ1 – θ) = m2c2 (θ – θ2) 

∴ c2 = 1 cal/gmºC 

∴ 50 × 0.6 × (120 – θ) 

= 1.6 × 103 × 1 × (θ – 25) 

θ = 26.8ºC

25.

The coolant used in chemical or in a nuclear plant should have high specific heat. Why ?

Answer»

So, that it absorbs more heat with comparatively small change in temperature and extracts large amount of heat.

26.

A gas is free to expand what will be its specific heat ?

Answer»

Specific heat : Infinity

27.

Why ends of a glass tube become rounded on heating ?

Answer»

When glass is heated, it melts. The surface of this liquid tends to have a minimum area. For a given volume, the surface area is minimum for a sphere. This is why the ends of a glass tube become rounded on heating.

28.

Name a substance that contracts on heating.

Answer»

Ice a substance that contracts on heating.

29.

What, according to the poet, would motivate the billion souls?(a) The dream(b) The song.(c) The vision(d) The speech

Answer»

(c) The vision

30.

“The Song of Youth” has..(a) an inspirational note(b) a personal note(c) a melancholic note(d) a satirical note

Answer»

(a) an inspirational note

31.

The Appalachians appear as low hills today.The Appalachians appear as low hills today.

Answer»

The Appalachians are old fold mountains and the glaciers and rivers have eroded them over millions of years. So they appear as low hills today.

32.

Give geographical reasons whyThe 49° N latitude and the 100°W longitude are important for North America.

Answer»

The 49° N latitude marks the boundary between Canada and United States whereas 100°W longitude passes through the centre of North America. So both are important.

33.

Fill in the blanks 1. A narrow stretch of land that joins North America to South America and separates the Atlantic Ocean from the Pacific Ocean : ......................2. The tropical islands, called the West Indies, are located in this sea : ...................... 3. Aphysical division of North America around the Hudson Bay which has the oldest known hard rocks of the world :.................4. A river that flows northwards and drains into the Hudson Bay : ....................

Answer»

1. A narrow stretch of land that joins North America to South America and separates the Atlantic Ocean from the Pacific Ocean : The Isthmus of Panama. 

2. The tropical islands, called the West Indies, are located in this sea : Caribbean Sea. 

3. Aphysical division of North America around the Hudson Bay which has the oldest known hard rocks of the world : The Canadian Shield. 

4. A river that flows northwards and drains into the Hudson Bay : River Meckenzie and River Nelson.

34.

Give geographical reasons whyThe Western Cordilleras form part of the ‘Pacific Ring of Fire’.

Answer»

The Western Cordilleras i.e. the western part of North America from Alaska to the Isthmus of Panama consists of young fold mountain ranges which contain very active volcanoes and lie close to the pacific ocean thus forming a part of the ‘ Pacific Ring of Fire’.

35.

List the four major physical divisions of North America. Describe any one of them briefly.

Answer»

The four major physical divisions of North America are the Canadian or Laurentian shield, the Western Mountain System or Western Cordilleras, the eastern highlands or Appalachians Mountains and the central lowlands or Great Central Plains. The Central lowlands extend from Hindsom Bay in the north to the Gulf of Mexico in the South covering distance of more than 6000 km and about 2000 km in width. They are also called the Great Central Plains. The plains are higher in West and slope northward in Canada. The main rivers which flow in these plains include Mackenzie, Mississippi—Missouri.

36.

Write about the largest river system of North America.

Answer»

The largest river system of America includes River Mackenzie falling into the Arctic Ocean. St. Lawrence, Hudson connecting all the Great Lakes draining into the North Atlantic Ocean, Yukon, Columbia falling into Pacific Ocean and Mississippi and Missouri rivers falling into Gulf of Mexico.

37.

Define Normal stress. Give its types.

Answer»

Here the force is applied normal to the surface is called Normal stress.

It is again of two types : Longitudinal and Bulk or volume stress. 

(i) Longitudinal stress 

(a) Deforming force is applied parallel to the length and causes increase in length.

(b) Area taken for calculation of stress is area of cross section. 

(c) Longitudinal stress produced due to increase in length of a body under a deforming force is called tensile stress. 

(d) Longitudinal stress produced due to decrease in length of a body under a deforming force is called compressional stress. 

(ii) Bulk or Volume stress 

(a) It occurs in solids, liquids or gases. 

(b) Deforming force is applied normal to surface at all points. 

(c) It is equal to change in pressure because change in pressure is responsible for change in volume.

38.

Define the Shear or tangential stress.

Answer»

It comes in picture when successive layers of solid move on each other i.e., when there is a relative displacement between various layers of solid. 

(i) Here deforming force is applied tangential to one of the faces. 

(ii) Area for calculation is the area of the face on which force is applied. 

(iii) It produces change in shape, volume remaining the same.

39.

How does the heat energy from the sun reach earth?

Answer»

By radiation.

40.

What attitude of the people is reflected in the refrain, ‘The answer is blowin’ in the wind’?

Answer»

It is the indifference of the people that is reflected in the refrain.

41.

How is the question about the mountain related to the other two questions in stanza 2?

Answer»

They all are unanswerable and thus they are related.

42.

Do these questions demand a specific answer? What do you call such questions?

Answer»

No, they don’t need. They are called rhetorical questions.

43.

Why does the writer say that the answer is blowing in the wind?

Answer»

The writer says that the answer is blowing in the wind because nobody knows the answer. Everybody tries to get it, but it slips away from our hold.

44.

Given below is a diagrammatic representation of a defect of the human eye:(i) Identify the defect.(ii) Mention two reasons for the above defect.(iii) State how the defect can be rectified.(iv) Name the part of the eye responsible for maintaining the shape of the eyeball.

Answer»

(i) Hypermetropia (Far-sightedness) because image is behind the retina.

(ii) Reasons for hypermetropia are:

1. Shortening of eyeball from front to back.

2. Lens becomes too flat.

(iii) It can be rectified by using convex lenses of appropriate power (focal Iength).

(iv) Sclerotic (or sclera).

45.

Given below is a diagram depicting a defect of the human eye. Study the same and then answer the questions that follows:(i) Name the defect shown in the diagram.(ii) Give two possible reasons for this defect of the eye in human beings.(iii) Name the parts labeled 1 to 4.(iv) Name the type of lens used to correct this eye defect.

Answer»

(i) Myopia, Short-sightedness.

(ii) The possible reasons for this defect may be:

(1) The eyeball is lengthened from front to back.

(2) The lens is too curved.

(iii) (1) Vitreous chamber.

(2) Fovea centralis (yellow spot)

(3) Lens

(4) Pupil .

(iv) This defect can be corrected by suitable concave lens.

46.

Study the following diagram carefully and then answer the questions that follow. The diagram is depicting a defect of the human eye :(i) Identify the defect shown in the diagram.(ii) Give two possible reasons for the above defect.

Answer»

(i) Farsightedness or hypermetropia.

(ii) (a) Lens is flattened or less convex,

(b) Eyeball is short.

47.

Name an old age eye defect. Why is it caused ?

Answer»

Hypermetropia. It is caused due to flattening of eye lens (Also presbyopia in which lens loses flexibility).

48.

Fluid present in the posterior chamber of the eye. Name it.

Answer»

Fluid present in the posterior chamber of the eye is Vitreous humour.

49.

The path which responsible for protecting the eye from sweat.

Answer»

Eye brows responsible for protecting the eye from sweat.

50.

The part of the eye responsible for change in the size of the pupil. Name it.

Answer»

The part of the eye responsible for change in the size of the pupil is Iris.