UPSC Previous Year GK Questions with Answers

The correct answer is D, Statement-I is incorrect, but Statement-II is correct. The atmosphere is heated mainly from below, by the Earth's own long wave (terrestrial) radiation, not directly by sunlight.

Incoming solar radiation is short wave, and the atmosphere is largely transparent to it, so most of it passes through and heats the Earth's surface. The warmed surface then gives off heat as long wave infrared radiation. Water vapour, carbon dioxide and other greenhouse gases absorb this long wave radiation well, and this is what warms the lower atmosphere. That is also why temperature normally falls with height in the troposphere.

A and B are wrong because Statement-I itself is false, so neither can be the answer.

C is wrong because it reverses the truth: Statement-I is the incorrect one, while Statement-II correctly describes greenhouse gases.

Exam tip: Sun gives short wave radiation that heats the ground; the ground gives long wave radiation that heats the air.

The correct answer is D, Dheera Shankarabharanam. Both ragas use all seven natural (shuddha) notes, the same scale as the Western major scale.

In Hindustani music, Bilawal is one of the ten thaats in Pandit V. N. Bhatkhande's system and is taken as the basic scale, with every note in its natural form. In Carnatic music, Dheera Shankarabharanam is the 29th melakarta raga of the 72-melakarta system and uses exactly the same set of notes. That is why musicians treat the two as counterparts across the two traditions.

A is wrong: Nat Bhairavi (20th melakarta) has a flat Ga, Dha and Ni, which matches Asavari thaat, not Bilawal.

B is wrong: Kamavardhini (51st melakarta) has a flat Re and Dha with a sharp Ma, close to Purvi thaat.

C is wrong: Hanumatodi (8th melakarta) has flat Re, Ga, Dha and Ni, which corresponds to Bhairavi thaat.

Exam tip: Bilawal = Shankarabharanam (all natural notes); Kalyan = Mechakalyani; Bhairavi thaat = Hanumatodi.

The correct answer is C, 1 and 3 only. BirdLife International is a worldwide partnership of independent national conservation organisations, with its secretariat at Cambridge in the United Kingdom, so statement 1 is correct. It is also the body that identifies and maintains the inventory of Important Bird and Biodiversity Areas, the sites that hold key populations of birds, which makes statement 3 correct. Statement 2 is the trap: the concept of biodiversity hotspots was proposed by the British ecologist Norman Myers in 1988 and was later developed by Conservation International, not by BirdLife International. Because statement 2 is wrong, option D, which takes all three, falls away, and option B, which keeps statement 2 while dropping the correct statement 1, is doubly wrong. Option A is incomplete because it leaves out statement 3. Remember the pairing: hotspots belong to Myers and Conservation International, Important Bird Areas belong to BirdLife.

The correct answer is C, marginal productivity of labour is zero. Disguised unemployment, also called hidden unemployment, exists where more persons are engaged in a job than are actually needed, so withdrawing one of them would not reduce output at all; that worker's marginal contribution is therefore zero. Indian agriculture is the classic illustration, where a whole family works on a holding that two members could manage. Option A is wrong because open unemployment, where people are visibly without work, is a different category altogether. Option B is wrong because the absence of alternative employment is a cause of the condition, not its definition. Option D is wrong because low productivity may arise from poor tools, poor soil or poor skills, which is a matter of degree, whereas disguised unemployment refers specifically to the zero marginal product of the surplus worker.

The correct answer is C, 1, 3 and 4. Under dyarchy the Governor kept the reserved subjects, which were those touching revenue and coercive power: administration of justice, land revenue, police, irrigation, famine relief, forests and labour relations. Local self-government, along with education, public health, agriculture, industries and excise, belonged to the transferred list, run by Indian ministers answerable to the legislative council. Option A is wrong because it includes local self-government, a transferred subject. Option B is wrong for the same reason, as it too carries local self-government. Option D is wrong because it drops land revenue, the most jealously guarded of the reserved subjects, and adds local self-government. The simple rule for the examination hall is that whatever earned money or kept order was reserved, and whatever spent money on people was transferred.

The correct answer is C, which is the statement that is not correct. The Kushana gold coins were struck on the same weight standard as the Roman aureus of the time, not on a different one, because the dynasty traded briskly with the Roman world and found it convenient to match that standard. The other three statements are sound. The Indo-Greeks issued the first Indian coins that carry the ruler’s name along with his portrait, a sharp change from the earlier punch-marked coins, which bore only symbols. The Kushanas, from Vima Kadphises and Kanishka onwards, issued the first gold coins in India in any quantity, with deities such as Shiva and the Buddha on the reverse. And their gold coins have indeed been found at many sites across north India and Central Asia, which is the clearest proof of how far their trade reached. Exam tip: punch-marked coins are the earliest, Indo-Greek coins the first with royal portraits, Kushana coins the first gold, and the Guptas issued the most gold coins.

The correct answer is A, Nizam Shahis : Bijapur, which is the mismatched pair. The Nizam Shahis ruled from Ahmadnagar, founded by Malik Ahmad in 1490, while Bijapur belonged to the Adil Shahis of Yusuf Adil Shah. All five Deccan Sultanates grew out of the break-up of the Bahmani kingdom between about 1490 and 1518, and four of them joined hands to crush Vijayanagara at the battle of Talikota in 1565. Bijapur is remembered for the Gol Gumbaz, Golconda for its fort and diamonds, and Ahmadnagar for Chand Bibi’s defence against the Mughals. Option B is a correct pair, because the Barid Shahis held Bidar, the last Bahmani capital. Option C is a correct pair, because the Qutb Shahis of Quli Qutb Shah ruled Golconda and later founded Hyderabad. Option D is a correct pair, because the Imad Shahis held Berar, the first province to break away and the first to be annexed by Ahmadnagar. Exam tip: Ahmadnagar Nizam Shahi, Bijapur Adil Shahi, Golconda Qutb Shahi, Bidar Barid Shahi, Berar Imad Shahi.

The correct answer is C, 1 and 4. The Royal Indian Navy mutiny began on 18 February 1946, when the ratings of HMIS Talwar in Bombay went on a hunger strike against bad food and racial insults. So items 2 and 3 were very much part of it, and the revolt soon spread to dozens of ships and shore establishments, with crowds and mill workers of Bombay coming out in support before Sardar Patel and Jinnah persuaded the ratings to surrender. Item 1 had no part in it: the Indian National Army was Subhas Chandra Bose’s force raised abroad, and although the INA trials of 1945 stirred the same anger, the army itself was already disbanded. Item 4 is also outside it, because the Viceroy in 1946 was Lord Wavell; Lord Irwin had left India in 1931, remembered for the Gandhi-Irwin Pact. Options A, B and D are wrong because each of them counts HMIS Talwar or the hunger strike, or leaves out the INA. Exam tip: RIN mutiny, 18 February 1946, HMIS Talwar, Bombay, under Viceroy Wavell.

The correct answer is C, Kolkata. The Kolkata port, now named Syama Prasad Mookerjee Port, stands on the Hooghly river about 200 kilometres inland from the Bay of Bengal, which makes it the only riverine major port in the country. Opened in 1870, it is also the oldest operating major port in India and serves a vast hinterland covering eastern India, Nepal and Bhutan. Its handicap is the silt the Hooghly carries: the channel must be dredged all the time, and because large modern ships still cannot reach the city, the Haldia Dock Complex was built downstream to take them. Option A is wrong because Mormugao in Goa is a coastal natural harbour at the mouth of the Zuari, famous for iron ore exports. Option B is wrong because Deendayal port, formerly Kandla, is a tidal sea port in the Gulf of Kachchh in Gujarat. Option D is wrong because Paradip in Odisha is an artificial deep water sea port on the coast. Exam tip: Kolkata is the only riverine major port, on the Hooghly, with Haldia as its deep water partner.

The correct answer is D, Chin Khilich Khan. Chin Qilich Khan, better remembered by his title Nizam-ul-Mulk Asaf Jah, was a Mughal noble appointed governor of the Deccan by Muhammad Shah. Tired of court intrigue at Delhi, he returned to the south, defeated his rival Mubariz Khan at Shakar Kheda in 1724 and from then on ruled the Deccan as an independent prince in all but name, founding the Asaf Jahi or Nizam dynasty of Hyderabad that lasted until 1948. He kept the forms of Mughal loyalty, struck coins in the emperor’s name, yet appointed his own officers and made war and peace on his own. Option A is wrong because Asaf Jah II, that is Nizam Ali Khan, was a later ruler of the same line, not its founder. Option B is wrong because Bahadur Shah was the Mughal emperor who ruled from 1707 to 1712. Option C is wrong because Alivardi Khan made himself independent in Bengal, not Hyderabad. Exam tip: Hyderabad 1724 Chin Qilich Khan, Awadh 1722 Saadat Khan, Bengal Murshid Quli Khan.

The correct answer is D, nickel. An alkene has a carbon-carbon double bond, and adding hydrogen across that bond turns it into the corresponding alkane. The reaction needs a finely divided metal catalyst, and nickel is the cheap industrial choice, usually at about 150 to 200 degrees Celsius; palladium and platinum do the same job at lower temperatures. The catalyst holds hydrogen molecules on its surface, splits them into atoms and lets them join the double bond, so it only speeds the reaction up and is not used up. The best known use is in food: unsaturated vegetable oils are hydrogenated over nickel to make solid vanaspati ghee. Option A is wrong because copper is used to dehydrogenate alcohols, which is the opposite kind of change. Option B is wrong because zinc dust is used for other reductions, not for adding hydrogen to a double bond. Option C is wrong because aluminium is not a hydrogenation catalyst at all. Exam tip: alkene plus hydrogen over nickel gives an alkane; oil plus hydrogen over nickel gives vanaspati.

The correct answer is C, Mizoram. Article 371G sits in Part XXI of the Constitution, which holds temporary, transitional and special provisions, and was inserted by the 53rd Amendment Act, 1986, when Mizoram was made a full state. It protects Mizo customary law and practice, social and religious usage, and the administration of civil and criminal justice based on that customary law: a law of Parliament on these subjects applies to Mizoram only if the Legislative Assembly of the state decides by resolution that it should. The Assembly is also fixed at a minimum of forty members. Option A is wrong because the special provision for Jammu and Kashmir was Article 370, whose operation was withdrawn in August 2019. Option B is wrong because Jharkhand has no such article; it was carved out of Bihar in 2000 by an ordinary reorganisation Act. Option D is wrong because Nagaland is covered by Article 371A, added by the 13th Amendment of 1962. Exam tip: 371A Nagaland, 371B Assam, 371C Manipur, 371F Sikkim, 371G Mizoram, 371H Arunachal Pradesh.

The correct answer is B, Separate Electorate. The Nehru Report of August 1928 was the draft constitution prepared by a committee of the All Parties Conference under Motilal Nehru, with Tej Bahadur Sapru, Subhas Chandra Bose and others, as Indians’ answer to Lord Birkenhead’s taunt that they could not agree on a constitution of their own. The report firmly rejected separate electorates, the device introduced by the Morley-Minto reforms of 1909, and asked instead for joint electorates with seats reserved for minorities where they were in a minority. Option A is wrong because dominion status was its central demand, which is exactly why the younger leaders who wanted complete independence objected. Option C is wrong because the report did favour a unitary and democratic centre with responsible government. Option D is wrong because adult suffrage, along with a list of fundamental rights, was one of its clear recommendations. Jinnah replied to it with his Fourteen Points in 1929. Exam tip: Nehru Report 1928 — dominion status, joint electorates, adult suffrage, fundamental rights.

The correct answer is B, inter cropping. In intercropping two or more crops are grown together on the same field at the same time, but sown in a definite pattern of rows, such as a few rows of soyabean between rows of maize, or bajra with lobia. The crops chosen have different nutrient needs and different rooting depths, so they use the soil, sunlight and water better, pests spread more slowly, and if one crop fails the farmer still has the other. It differs from mixed cropping, where the seeds of two crops are simply mixed and broadcast with no row pattern. Option A is wrong because crop rotation means growing different crops one after another on the same field in successive seasons, to restore fertility. Option C is wrong because alternate cropping is not the name for sowing two crops side by side in the same season. Option D is wrong because kharif names a season, the monsoon crop sown in June and July, not a method of cropping. Exam tip: mixed cropping has no rows, intercropping has definite rows, rotation is one crop after another.

The correct answer is D, Nitrogen. Nitrogen makes up about 78 per cent of the atmosphere, yet it is not a greenhouse gas. A molecule traps heat only if it can absorb outgoing infrared radiation, and that needs vibrations which change the spread of electric charge in the molecule. Nitrogen is a simple molecule of two identical atoms, so it is transparent to infrared; the same is true of oxygen. The gases that do trap heat are water vapour, carbon dioxide, methane, nitrous oxide, ozone and the halocarbons, and together they keep the earth about 33 degrees Celsius warmer than it would otherwise be. Option A is wrong because water vapour is the most abundant greenhouse gas of all. Option B is wrong because chlorofluorocarbons are powerful greenhouse gases that also destroy the ozone layer, which is why the Montreal Protocol phases them out. Option C is wrong because methane traps far more heat per molecule than carbon dioxide. Exam tip: nitrogen and oxygen are not greenhouse gases, though they make up most of the air.

The correct answer is A, whatever the change in price, there is absolutely no change in demand. Price elasticity of demand is the percentage change in quantity demanded divided by the percentage change in price. If the elasticity is zero, the numerator is zero: buyers take the same quantity however the price moves. This case is called perfectly inelastic demand and its demand curve is a vertical straight line. Textbooks illustrate it with a life-saving medicine or with salt, goods a household buys in a fixed quantity because there is no substitute and the spending is small. Option B is wrong because a small response to a small price change means elasticity between zero and one, that is inelastic but not zero demand. Option C is wrong because a large response to a small price change is elastic demand, with elasticity greater than one. Option D is wrong because that too describes ordinary inelastic demand, where some change still takes place. Exam tip: elasticity zero is a vertical curve, elasticity infinity a horizontal one, and elasticity one is unitary.

The correct answer is B, Qila-i-Kuhna Masjid. This mosque stands inside the Purana Qila in Delhi and was built by Sher Shah Suri around 1541, during the Sur interregnum that interrupted Mughal rule, so it belongs to a period before Shah Jahan was born. Its five arched bays in red sandstone with marble inlay are counted among the finest pre-Mughal mosques of Delhi. Shah Jahan, who ruled from 1628 to 1658, is the great builder of the dynasty: he raised Shahjahanabad with its Red Fort, the Taj Mahal at Agra and the Peacock Throne. Option A is wrong because the Moti Masjid, the pearl mosque in white marble, was built in the Agra Fort in his reign. Option C is wrong because the Jama Masjid of Delhi, the largest mosque in India, was completed under him in 1656. Option D is wrong because the Rang Mahal is one of the painted palaces of his Red Fort. Exam tip: Purana Qila and its Qila-i-Kuhna Masjid belong to Sher Shah Suri, not the Mughals.

The correct answer is D, Neon. When electricity is passed through a sealed tube holding neon at low pressure, the gas atoms are excited and give out a bright orange-red glow, which is why advertising signs are still called neon signs. Neon is a noble gas discovered in 1898 by Ramsay and Travers; it is chemically inert, forms no ordinary compounds, and is also used in voltage testers, high-voltage indicators and lightning arresters. Every gas glows in its own colour in a discharge tube, and that colour is the fingerprint of its atomic energy levels. Option A is wrong because helium gives a pale pinkish-white glow and is better known for filling balloons and airships. Option B is wrong because argon glows a pale violet-blue and is used to fill electric bulbs and to shield welding. Option C is wrong because nitrogen glows bluish, and its common uses are as an inert packing gas and as a liquid coolant. Exam tip: neon gives red light in a discharge tube, while argon is the gas that fills ordinary electric bulbs.

The correct answer is A, temperature is highest at ground level and decreases with increasing altitude. In the troposphere the air is warmed mainly from below: the earth absorbs incoming short-wave insolation and then heats the layer of air touching it by conduction, radiation and convection. So the farther you go from this heat source, the colder the air, and the normal lapse rate is about 6.5 degrees Celsius for every 1,000 metres of ascent. This is why hill stations are cool in summer and high peaks stay under snow even in the tropics. Option B is wrong because that upside-down pattern is a temperature inversion, a local and short-lived reversal seen in valleys on calm clear winter nights, not the normal rate. Option C is wrong because temperature does not stay steady with height; the troposphere cools steadily upward. Option D is wrong because no such initial warming occurs in the normal profile. Exam tip: normal lapse rate is a fall of about 6.5 degrees Celsius per kilometre; the opposite is called an inversion.

The correct answer is D, New Delhi. The National Green Tribunal was set up by the National Green Tribunal Act, 2010, and started work on 18 October 2010 with its principal bench at New Delhi. Its four zonal benches sit at Bhopal, Pune, Kolkata and Chennai, and it also holds circuit sittings at other places. India thus became one of the first countries to create a dedicated court for environmental disputes, and the tribunal is required to decide cases within six months of filing. It hears matters under laws such as the Water Act, the Air Act and the Environment (Protection) Act, is headed by a chairperson who has been a judge of the Supreme Court or a High Court Chief Justice, and its orders can be appealed only in the Supreme Court. Option A is wrong because Kolkata holds the eastern zone bench, not the principal seat. Option B is wrong because Hyderabad has no bench of the tribunal. Option C is wrong because Lucknow is not the principal seat either. Exam tip: NGT Act 2010 — principal bench Delhi; zonal benches Bhopal, Pune, Kolkata and Chennai.