UPSC CS Pre 2010 Physics Answer key SET C

Hi,

Disclaimers:
1. There are bound to be discrepancies in the key. I'm just providing a starting point to initiate the process of discussions and debates so that we can ultimately arrive at the legitimate solution.
2. I have left few questions unanswered( which ofcourse I don't know) by simply putting * in place of answer.
3. The answers for which I wasn't sure about carry ** before question number.


SET C Answers:

Answer SetC
1.A-----flux density in emw
2.C---antiferro
3.A—reading of Galvanomtr
4.C---slope=planks const
5.*--compton
6.C--j=1/2
7.A---energy=5mc^2/3
8.B---U235
9.A—form of wave function
10.B---carnot relation betwn y and x
11.*---2nd order transition
12.B---harmonic osccil min energy etc
13.B--- newton ring in a liq
**14.D--- diff function of numbr of lines
15.A---coin’ll appear shiny
16.C---SHM ellipse
**17. C----distnce betwn 2 dark
18.C--- 1.44
19.D—centre of mass v=0
20.C—emitter is fwd biased…
21.A…zero electric field at centre
22.D….BI along y
23.D….currnt in j direction
24.A….5ohm
25.C…problity current
26.A…1/a27.C….leptons forces
28.B..plank
29.D….kinetic energy equalfor both H and N
30.A…escape vel non of above
31.* projection of circular motion
32.D…work done by chain
33.D….zero earth sun
34.D…escape vel 4R
35.B…m=13
**36.C…will be virtual
37.B…population inversion in Ne
38.C…both mirage n plane mirror image
**39.B…van de graff
40.A….cyclotron
41.D…q/2 q/2
**42.B….B=mu*H di ferro para
43.C….particle at rest decay
44.C….flywheel
45.A…..range max height
46.A….phase diff b/w SHM
47.C….speed of masses in G
48.B…exponentially decresing
49.A….kinetic energy of planet
**50D….both E and P conserved
51.B…new terminal vel
52.D…observer ‘ll hear 1 beat
53.C….MI of disc
54.D = 0.65
55.A…122.4ev
56.D…transmission prob
**57.B…stern gerlach
**58.B…Zeeman
59.A…p-q/pq
60.*
61.C….0.79ev
62.C…e-2
63.B…wave function continuos
64.A…X ray l alpha k alpha
65.B…gamma mixture=1.5
66.C…entropy increase
67.D….heat capacity
68.D..weins displcmnt law
69.B….1.5J
70.C…drift n diffusion
71.D…acquire negtve chrge
72.C…exponential way
73.B…thin film appears black
74.B…velocity vector
75.A…R-1 escape vel
76.C….square root of temp
77.B….20ma
78.D….independnt of r
**79.A…dopant concentration
80.B…r1v1/r2
81.D…speed=1
82.D…hysteresis
83.C…Huygens eyepiece
84.D….interfrnce beam coherent etc.
85.A…50000
86.D…60 cm
87.B…30degree
88.A…=1time period ratio alpha and proton
89.B….-3E/5
90.A…2/3V
91.C…L>2f
**92.D HE-Ne grating---will remain same
**93.C microscope telescope
**94.A…0.6mm(ooptions were in nm)
95.A…parabolic mirror
96.C…harmonic oscill resonance
97.C…moving clock
98.B….capillary h to h/3
99.D…Be++
100.D…electricflux zero
101.A….YDSE Stmt 1 2 type(101-105)
**102.C
103.C….particle barrie
**104.C…streamline
105.D…relativity
106.A…soft iron
107.A…van der wall work
108.D….chnge in entropy
**109.B…D and eta unchanged
110.A….logic gates
111.B…zener 250ohm
112.D….p/n impurity band gap unchnged
113.* opacity
**114.B…astigmatism
115.B….ratio of intensity 1/3
116.D….plane polarized light 1,2,3
117.A…=vel of light
118.B….Q factor
119.B…45 degree phase diff
120.D….By Bx Bz

1….2……3-Go………..

Free flow of information and communication is a fundamental pillar of socio economic development of a society. World Bank and other international organizations use it as one of their criteria for evaluating ‘good governance’ among nations. The world has always dreamt of living in an age where every human is connected to one another. In 1980s with the invention of mobile telephony this long dream of humankind seemed to be materialized. Since then we have come a long way.
The cut-throat competition in the telecom sector on the one hand has relieved the users from paying hefty bills and on the other hand amplified various services available. Present technologies like CDMA, GSM etc. were successful in trickling down their impacts to reach to the datum. People including the rickshawallahas have now learned to keep the mobiles in their pockets. With such a hold of mobile phones on our society, debates over the latest technologies are bound to take off.
India though lately has decided to go 3G. 3G auction has already created a roar in the country of more than 400 million mobile users. It is a third generation of wireless mobile telephony where mobile communication converges with high speed internet services. It allows simultaneous use of speech and data services and higher data rates. It carries a huge potential as an instrument for bringing socio economic changes. Apart from being a boon for high data-rate freaks, it also opens up new opportunities for the rural users. It exposes rural people to the wide world of web where computers are still out of reach but most of them do possess mobile phones. It may prove a life- altering experience for them. The one sector which needs it badly is Telemedicine; with still a large number of rural areas lacking in effective medical care the new technologies like 3G arises new hopes. It can revolutionize the way financial and banking sector perceives rural customers. Education is yet another field where it can contribute for instance the implementation of “one laptop per child” may look tedious but “one 3G phone per classroom” is definitely in reach. It also brings in the novel opportunities like online purchase of seeds and fertilizers etc. in places where still computers are rare sight. It also has its share in simplifying agricultural marketing by knowing the current prices, trends etc. on the phone. Thus for rural upliftment, It could be a much needed shot in the arm.
In a recent study it was observed that broadband penetration is directly proportional to the GDP growth of a nation. With more people connected, the businesses amplify accordingly. It’ll enable Indian employees to remote desktop enterprise solutions and also reduce their response time to the customers leading to the increased productivity. The high data rate and optimized service will enhance the competitiveness in the market.
In this cricket and movie crazy nation the 3G set makers are not all over optimistic in considering entertainment sector as the major economy generator driven by 3G services.
Thus 3G services will definitely add to our long fight of creating awareness among people. The citizens will realize the power of being in touch and that will surely put pressure on the politicians and bureaucrats to deliver on ground.
Meanwhile, financial and health services using 3G have already reached a level of convenience and safety in western world and are just getting ready to take off ground in India.

Agriculture in India: Contemporary Issues

India has a long history of agriculture. It’s about ten thousand years since the first seedling sprouted here. India’s 60% manpower still earns its livelihood from farm sector. We are among the largest producers of most of the cereals, cash crops, vegetables and fruits. When the agricultural output of India dribbles, food prices all over the world shoot up. We drive the food economy of the world. Though India leads in terms of gross output but our productivity is dismally low. We have some serious issues to be resolved. The large subsidies being given in the form of fertilizer subsidy, loan waivers etc. are continuing to lay heavy burden to the exchequer. This eats up bulk of govt. spending in the sector resulting in meagre amount left for innovations to be tried out. There are issues with the concept of minimum support price (MSP) too. Every financial year witnesses a whooping increase in MSPs. Govt. makes it a point to lift them in order to avoid any political consequence. The whole idea to repudiate the cobweb cycle is creating a new Frankenstein’s monster. The wide spread social backwardness and illiteracy along with the decreasing average land size hampers the future prospects. We have a poor credit delivery mechanism. There is a need to revitalize the cooperative credit structure. The cooperatives are at the crossroads of existence in this globalised and liberalized world. The commercial banks should be persuaded to aim for inclusive growth. Some pre operating conditions can be put on the foreign banks to strengthen the rural banking structure. The present farm- industry interface is too weak to cater to the needs of large sector. The innovations achieved in lab never reach down to the poor while the field breakthroughs hardly get their due recognition. There is a huge scope of R&D in the sector and the tillers need them badly. After ten thousand years of agro civilization, we are still dependent primarily on the monsoon to irrigate our farms. The agricultural output oscillates between robust and sluggish depending on the year’s monsoon. Water shed developed programs should be implemented in all spirit. The marketing channels for agricultural goods are too complex lacking in the basic infrastructure. We need to revamp post harvesting mechanisms, build storage capacities, ensure standardization and deploy proper grading system to protect farmers. A new threat due to climate change and global warming is questioning the very existence of the life on earth. Agriculture is one of the most vulnerable sectors. People often talk about 2nd green revolution but that in the absence of technological breakthroughs seems improbable. Organic farming is the one promising field where India can make the best use of its large organic wastes to reduce its reliance on synthetic fertilizers. We have a tremendous potential to develop a rich culture of bio fertilizers, bio pesticides and green manure. There is a strong wave going in favor of diversification of traditional crop patterns and agro practices. Diversification is the need of the hour. Most of our farmers thrive upon subsistence agriculture. The fields of horticulture, fishery, poultry, hatchery, silkworm farming etc. if efficiently capitalized can provide them profitable business during low times. The National Bamboo Mission launched by Govt. is an honest effort in this direction. The local needs specific interventions can truly bear fruits. Every now and then we found ourselves grappled in the food shortages and inflation. The situation mandates us to focus on low yielding areas. Crops like pulse, oilseeds need to be given a boost. A dedicated organization promoting the rural entrepreneurs, innovators, mechanics and other local skilled people must be set up. Besides these awareness has to be spread among farmers and cultivators regarding the upcoming technologies, export prospects, govt. policies etc. Recently govt. announced the renovation of hundreds of ITI’s for the purpose. A lot of Kisan Call Centres have also become operational. The power shortage can be addressed by setting up mini power plants in the villages which use bio fuels, solar, wind, rice husk etc. as its fuel. Funds for National Solar Mission which aims at installing capacity of 20k MW by 2020 can be utilized for the purpose.
Thus there are plenty of agendas before the nation to be addressed. The challenge is to evolve the best agricultural practices based on local experiences making optimum use of resources. The idea is to create ecologically sustainable, economically efficient and socially equitable agriculture in India.

Love, Sex and Dhokha

I’m a big fan of Dibakar Bannerjee. The way he propagates his ideas is truly novel though all his movie characters could easily be seen walking on street sides, travelling in buses, trading in markets etc. He has earned himself an image of trend setter in bollywood. One can expect unseen from his films but LSD seems to have an adapted screenplay. Love, sex and dhokha all three are the basic ingredients of US-Pakistan relationship. Their love begun in early 1950’s with the Washington visit of then PM of Pakistan Liaqat Ali Khan. This was an era when both India and Pak were laying foundations of their foreign policies. It’s always easy for a Pakistani foreign policy maker to take decision, the golden rule is simply follow the path opposite to the one adopted by India. During the cold war when the big brother decided to stay non-aligned the younger followed a pro western policy. US-Pak were engaged in a relationship by the time SEATO and CENTO were signed in mid 50’s. US had already committed to a Mutual defence agreement with Pak. It termed Pak as its ‘most allied ally’ in south Asia and the exchange of cards and letters became the order of day. They were in love but yet not ready for intercourse. Next few years were stagnant as US was engaged in evolving latest cold war tactics to stop Soviets in its track. Two decades old relationship then hit an all time low during the Indo-Pak war 1965 when US terminated the military assistance to Pak. This was for the first time the Islamic state tasted the ‘dhokha’ from its partner. There was simply no reason for US to continue aid Pak. Though USA was against the very sense of liberating Bangladesh but the Americans knew that any military action against India would led them to confrontation with USSR. They adopted the policy of wait and watch and finally ended up as a mere audience of Indira’s show. Yet another ‘dhokha’ from the beloved lover. US formed CENTO to check any south west expansion of Soviet Union. Pak was its prominent partner but the idea collapsed with the Iranian Revolution in 1979. Soon things turned around when USSR invaded Afghanistan in Dec 1979 and US was dying to put breaks on the Soviet’s intentions. USA was in dying need of some soil in South Asia to counter Russians and Pakistan was its but obvious choice. Time has come for a pet to pay its master. This was the beginning of a new chapter titled “Kamasutra” in the US-Pak relationship. US with the help of ISI provided arms, training, intelligence and financial aid to Mujahideens in order to throw out Soviets from the land of Afghans and it indeed happened. The Russians pulled out their forces in 1988 and by that time Pakistan had gone richer by many billion dollars but the saga of their first night didn’t last long. In 1990, Clinton administration cut off military aid to Pak on the issue of nuclear proliferation. In May, 1998, India conducted nuclear tests to prove its strength to the world. Pak had no choice left except for retaliating back by conducting its own test. That fusion reaction deepened the fission between the future ‘strategic partners’. The furious west this time put some serious sanctions on both India and Pak. While India still backed upon its intimacy with Russia and other developing countries, US-Pak relations were going nowhere. All credit then goes to Al Qaeda and the Taliban for creating the conditions which were impossible pre 9/11. They rejuvenated two lovers and fixed their marriage. Pak army along with NATO forces cracked heavily on Taliban and fundamentalists. Sometimes they often found themselves perplexed as if they were fighting against their own people. After almost a decade of war both nations seems to have lost more than gain from the “war on terror”.
2010: USA is now finding it difficult to sustain war on two fronts. Pakistan’s economy is drowning each day with the growing threat of Taliban. Though Obama reinforced the lost belief that war can be won but the ground reports are negative. Recently US-Pak shared a strategic dialogue where US committed to triple its military aid to Pak to reach up to 1.5b$ per year for the next 10 years. No one knows where this money will go and what’ll be the future of the region but one thing is sure US’s commitment for the next 10 yrs shows there is still plenty of time left for the world to witness yet another ‘dhokha’ in this formidable love story. It’s upon Pak to make the most of it, to reconstruct their country before the region is stabilized and Uncle Sam is gone. By the way, 5 star to Bannerjee for his work.

Revamping education in India

Education in India has a history stretching back to the ancient urban centres of learning at Nalanda and Taxila. Western education became a part of it with the establishment of British Rule. The independent India constitutionally recognized the need to revitalize education. It is kept under the control of both state and central governments with state given the primary responsibility. There is a recent trend of increasing role being played by central govt. through its various centrally sponsored flagship programs. Notably India’s total spending on education has increased from 1.5% of GDP in 1950s to about 3.5%.
Education not only creates economic opportunities but also increases productivity, develops social and national unity, modernizes the country, consolidates democracy, removes gender disparity and develops social and spiritual values. Thus it’s a backbone for all round growth of a country. But a growth which is not ‘inclusive’ won’t lead to the development. Inclusiveness should be the hallmark of education system. It’s really sad that even after spending so much of time and resources we were unable to bridge gaps created by gender disparities, castism, rich- poor divide etc. though our absolute literacy rate has increased from mere 18% to 64%.
It doesn’t really matter how many universities we have, how many colleges we open until we built a firm structure for universalizing primary education. A step ahead could be the quick enactment of proposed Right to Education Act. We have to make sure it doesn’t become a mere piece of paper. Its fair implementation is must. Another issue is the abysmal Gross Enrolment Ratio in higher education which stood at meager 11%. This may be sufficient to meet the needs of graduates now but for India with its big dream of becoming a superpower, certainly signs are not encouraging.
It’s good to talk about the reforms in secondary exams, creation of NCHER, creation of new IIT’s etc. but all would be in vain if we can’t include the deprived sections of society. Also it will be useless if we fail to create the productive manpower we need. Moreover there is no practical relationship between theory being taught and industrial requirements. Thus what we are producing are the piles of young unemployable graduates. There is an urgent need to revitalize Vocational Education in India. The demand for vocational skill is large and its growing yet vocational sector is small and has not grown fast enough due to its poor image. Even professionals due to lack of vocational training sometimes have unidimensional outlook. Only a unified educational and training sector can respond to the changing job markets.
Gender disparity has always remained the integral part of our education system. Despite the various governmental incentives and schemes like Mahila Samakhya, Sarva Shiksha Abhiyan etc. gender literacy gap still stood at 21% with only 54% literacy rate among females compare to 75% that of males. A literate woman not only contributes to the economic productivity but also helps in reducing maternal mortality rate, infant mortality rate, fighting HIV/AIDS, arising environmental awareness etc. A new model can be tried by combining the health and education sector schemes. Imagine ASHA (Accredited social health activists) taking classes for pregnant women in Primary Health Centers.
Another roadblock is the quality of teachers available. No compromise should be made. Reforms like giving them additional incentives to live in remote places, hiring them on contract basis, recruiting from local people etc. should be realized on ground level. Reservation for teachers in higher educational institutional should not be given a serious thought.
We are also lagging behind in creating the infrastructural and institutional requirements. China and other developing countries are far ahead of us. Indianised Public Private Partnership Model can be used to fulfill the infrastructural needs of the sector.
While there is lot that government needs to do to provide quality education to its people, responsibility also lies on the society. There are growing numbers of NGOs and more young people are joining them then anytime before. This social consciousness needs to be encouraged and amplified. We are in the process of building a knowledge society. The time has surely come when we should march ahead hand in hand towards achieving the global Millennium Development Goals. Shouldn’t We???