Defence Previous Year GK Questions with Answers

The correct answer is B, it slows down and bends towards the normal. A denser medium has a higher refractive index, and the refractive index is the speed of light in vacuum divided by its speed in the medium, so light must travel more slowly inside it. When the ray meets the surface at an angle, the part of the wavefront that enters first is slowed first, which swings the ray towards the normal. Air to glass and air to water are the standard examples.

Option A takes the correct change of speed with the wrong bending. Option C describes what happens in the opposite case, when light passes from a denser medium to a rarer one. Option D combines two errors at once. A ray that falls along the normal is a special case and passes straight through without bending, though its speed still changes.

The correct answer is The Council of Ministers. A no-confidence motion tests whether the government still has the support of the Lok Sabha, and because the Council of Ministers is collectively responsible to that House under Article 75(3), the motion is moved against the Council as a whole, never against a single minister. It can be moved only in the Lok Sabha, needs the support of at least 50 members to be admitted and does not have to state reasons. If it is passed, the whole Council must resign.

An individual minister cannot be targeted by a no-confidence motion; Parliament can express disapproval of a minister's policy through a censure motion, which must give reasons. The Prime Minister is not singled out either: the motion is against the government the Prime Minister leads. A political party is not answerable to the House at all. The first no-confidence motion in the Lok Sabha was moved in 1963 against Jawaharlal Nehru's government by Acharya J.B. Kripalani, and it was defeated.

The correct answer is 91st Amendment. The 91st Amendment Act, 2003 inserted Article 75(1A), which says the total number of ministers, including the Prime Minister, in the Union Council of Ministers shall not exceed 15% of the total number of members of the Lok Sabha, and Article 164(1A), which applies the same limit to the States, with a minimum of 12 ministers. It also barred a member disqualified for defection from being appointed a minister, and strengthened the anti-defection law by deleting the provision that allowed "splits".

The other amendments are from around the same time but on different subjects. The 97th Amendment (2011) dealt with co-operative societies. The 87th Amendment (2003) provided for delimitation of constituencies on the basis of the 2001 census. The 90th Amendment (2003) concerned representation in the Assam Legislative Assembly from the Bodoland Territorial Areas District. The 15% cap was meant to stop jumbo ministries formed to reward supporters and hold coalitions together.

The correct answer is To value and preserve a unitary national culture. Article 51A(f) actually asks citizens "to value and preserve the rich heritage of our composite culture". The word matters: India's culture is described as composite, a blend of many traditions, languages and faiths, not a single unitary culture. By changing one word, the examiner turns a real duty into a false one.

The other three options are genuine duties. Rendering national service when called upon to do so is part of clause (d). Renouncing practices derogatory to the dignity of women is part of clause (e), which also asks citizens to promote harmony across religious, linguistic and regional diversities. Developing the spirit of inquiry and reform is part of clause (h), along with the scientific temper and humanism. This question is a reminder to learn the exact wording of the duties, because CDS and UPSC papers often test a single changed word rather than the whole idea.

The correct answer is A, Unity and Discipline. The motto of the National Cadet Corps is Unity and Discipline, in Hindi Ekta aur Anushasan. The NCC was set up in 1948 under the National Cadet Corps Act, 1948, and works under the Ministry of Defence with its headquarters in New Delhi. It trains school and college students through its Army, Navy and Air wings, and cadets holding the C certificate can become Army officers through the NCC Special Entry without writing the CDS paper. NCC Day is celebrated on the fourth Sunday of November every year. An easy way to remember the motto: a cadet's two first lessons are to stand together and to follow orders. B is wrong, because Unity and Integrity is not the NCC motto. C is wrong, because Unity and Command is a made-up pairing. D is wrong, because the word service belongs to the Indian Army's motto, Service Before Self, not to the NCC's. Exam tip: NCC, 1948, Ministry of Defence, motto Unity and Discipline, NCC Day on the fourth Sunday of November.

The correct answer is B, Assam Rifles. It is the only such force whose administrative control lies with the Ministry of Home Affairs while its operational control lies with the Indian Army. The Assam Rifles is also India's oldest paramilitary force, raised in 1835 as the Cachar Levy to guard British tea estates and settlements in the North East. Most of its officers come on deputation from the Army; it guards the India–Myanmar border and runs counter-insurgency operations in the North East, which is why it is called the Sentinels of the North East and the Friends of the Hill People. A is wrong, because the CRPF, India's largest central armed police force, is fully under the Home Ministry. C is wrong, because the ITBP, raised in 1962 to guard the border with China, is also under the Home Ministry alone. D is wrong, because the CISF, set up in 1969 to protect industrial units, airports and metros, reports only to the Home Ministry. Exam tip: Assam Rifles, raised 1835, Home Ministry for administration and Army for operations, guards the Myanmar border.

The correct answer is B, greenhouse gases emission. The Kyoto Protocol, adopted at Kyoto, Japan on 11 December 1997 under the UN Framework Convention on Climate Change, was the first treaty to set binding targets for cutting emissions. It came into force on 16 February 2005 and asked industrialised countries to cut their greenhouse gas emissions by an average of about 5 per cent below 1990 levels during 2008 to 2012. It covered six gases, including carbon dioxide, methane and nitrous oxide, and created market tools such as the Clean Development Mechanism, which let projects in countries like India earn carbon credits. India ratified it in 2002 but, as a developing country, had no binding target. A is wrong, because cutting poverty is the aim of goals such as the UN Sustainable Development Goals, not Kyoto. C is wrong, because nuclear arms are dealt with by treaties like the Non-Proliferation Treaty of 1968. D is wrong, because farm subsidies fall under the WTO's Agreement on Agriculture. Exam tip: Kyoto 1997, in force 2005, binding cuts for rich nations; Paris 2015, pledges from all nations.

The correct answer is A, 1 only. Statement 1 is true and statement 2 is false. Race to Zero is a global campaign backed by the United Nations and launched in 2020, ahead of the COP26 climate talks in Glasgow. It rallies businesses, cities, regions, investors and universities to take rigorous action to halve global emissions by 2030 and reach net-zero emissions by 2050 at the latest, in line with the Paris Agreement aim of limiting warming to 1.5 degrees Celsius. Building momentum for a shift to a decarbonised economy is exactly its aim, so statement 1 is correct. Statement 2 is wrong: the zero in the name means net-zero carbon emissions, not a zero-sum game, where one side's gain equals the other side's loss; climate action is meant to benefit everyone. B is wrong, because statement 2 is the false one. C is wrong, because it accepts the false zero-sum statement. D is wrong, because statement 1 correctly describes the campaign. Exam tip: Race to Zero, UN-backed, 2020, halve emissions by 2030, net zero by 2050.

The correct answer is B, Roasting. Roasting means heating a sulphide ore strongly in plenty of air, so that the sulphide turns into an oxide and the sulphur escapes as sulphur dioxide gas. The standard example is zinc blende: 2ZnS + 3O2 gives 2ZnO + 2SO2. An oxide is easier to reduce to the metal with carbon, which is why ores of zinc, lead and copper first pass through this step. Remember the key contrast: roasting uses excess air and suits sulphide ores, while calcination uses limited or no air and suits carbonate ores. A is wrong, because calcination heats carbonate ores such as calamine in limited air, as when ZnCO3 gives ZnO and CO2. C is wrong, because smelting is the later step in which the oxide is reduced to metal in a furnace with a reducing agent and a flux. D is wrong, because incineration is burning waste at a high temperature, not a step in extracting metals. Exam tip: sulphide ore, roasting, excess air; carbonate ore, calcination, little or no air.

The correct answer is D, Proteins. Kwashiorkor is caused by a severe lack of protein in the diet, even when the child gets some calories from starchy food. It usually strikes children aged one to five after they stop breastfeeding and are fed mostly rice, maize or cassava. The tell-tale signs are a swollen belly and puffy legs due to fluid retention (oedema), a moon face, peeling skin, thin reddish hair and poor growth. The word comes from Ghana and is often explained as the sickness of the older child pushed off the breast when a new baby arrives. Its cousin marasmus comes from a lack of both protein and calories and leaves the child wasted, with no swelling. A is wrong, because mineral shortages cause other diseases, such as anaemia from lack of iron and goitre from lack of iodine. B is wrong, because vitamin deficiencies cause scurvy, rickets and night blindness, not kwashiorkor. C is wrong, because a lack of fat is not what causes kwashiorkor. Exam tip: kwashiorkor, protein only, swollen belly; marasmus, protein and calories, wasting.

The correct answer is C, Red blood cells. Mature red blood cells, or erythrocytes, lose their nucleus before they enter the blood. Losing the nucleus, and the mitochondria too, leaves more room for haemoglobin, the iron-rich protein that carries oxygen, and gives the cell its flexible biconcave disc shape, which lets it squeeze through narrow capillaries. With no nucleus, red blood cells cannot divide or repair themselves; they live about 120 days, are made in the red bone marrow and are broken down mainly in the spleen, often called the graveyard of red blood cells. Platelets also lack a nucleus, but they are cell fragments, not whole cells. A is wrong, because muscle cells have nuclei, and skeletal muscle fibres even have many. B is wrong, because phagocytic cells such as neutrophils and macrophages have a nucleus; a neutrophil's nucleus has several lobes. D is wrong, because the ciliated cells lining the windpipe and the oviduct are normal cells with a nucleus. Exam tip: human red blood cells have no nucleus, live 120 days, are born in bone marrow and end in the spleen.

The correct answer is C, Abscisic acid. It is the main growth inhibitor among plant hormones and works against the growth promoters. Abscisic acid, or ABA, is called the stress hormone because it helps plants survive drought, cold and salt: it makes the stomata close to save water, keeps seeds and buds dormant so they do not sprout in bad weather, and helps leaves and fruits to age and fall. So when a question asks which hormone slows or stops growth, ABA is the answer; ethylene is the other hormone linked with ageing and ripening. A is wrong, because auxins promote growth by making cells elongate, and they make shoots bend towards light. B is wrong, because cytokinins promote cell division and delay the ageing of leaves. D is wrong, because gibberellins promote stem elongation, break seed dormancy and are sprayed on grapes to increase their size. Exam tip: the growth promoters are auxin, gibberellin and cytokinin; the inhibitor is abscisic acid, the stress hormone.

The correct answer is C, erect, virtual and larger than the object. For a lens, magnification m is the image height divided by the object height, which also equals v divided by u. A plus sign means the image is erect and virtual, and a value of 2 means it is twice as tall as the object. Only a convex lens can form such an image, when the object is placed between the optical centre and the principal focus; this is exactly how a magnifying glass or a simple microscope works. A concave lens also forms erect, virtual images, but they are always smaller, so its magnification stays between 0 and plus 1. A is wrong, because an erect, virtual, smaller image needs m between 0 and 1, as with a concave lens. B is wrong, because a real, inverted image always has a negative magnification. D is wrong, because a real, inverted, enlarged image would have m below minus 1, such as minus 2. Exam tip: the sign tells the type, plus for virtual and erect, minus for real and inverted; a value above 1 means enlarged.

The correct answer is B, Vote on Account. It is the advance grant the Lok Sabha makes so that the government can keep spending from 1 April until the full budget is passed. Article 116 of the Constitution allows it. No money can leave the Consolidated Fund of India without Parliament's approval, so this grant fills the gap. It usually covers two months, about one-sixth of the year's estimates. Since the budget moved to 1 February in 2017, it is mostly seen in election years, when the outgoing government leaves the full budget to the new Lok Sabha. A is wrong, because a vote of credit, also under Article 116, is a blank-cheque grant for an unexpected need that cannot be stated in detail. C is wrong, because the Appropriation Bill under Article 114 authorises withdrawal from the Consolidated Fund after the demands are voted. D is wrong, because advance account is not a budget term of the Constitution. Exam tip: vote on account keeps the government running, vote of credit is the blank cheque; both sit in Article 116.

The correct answer is A, Any privately held startup company with a value of over $1 billion. A unicorn is a startup that is not listed on the stock market and is valued at more than one billion US dollars. The term was coined in 2013 by the American venture capitalist Aileen Lee, who picked the mythical animal because such startups were then very rare. Related words follow the same pattern: a decacorn is valued at over 10 billion dollars and a hectocorn at over 100 billion dollars. Once a unicorn lists its shares through an IPO, it becomes a listed company and, strictly speaking, is no longer called a unicorn. B is wrong, because merging one public sector company with another, as done with several public sector banks, is consolidation. C is wrong, because selling a loss-making state-owned company is privatisation or disinvestment. D is wrong, because a foreign firm working with an Indian partner forms a joint venture. Exam tip: unicorn, private startup, over 1 billion dollars; decacorn, over 10 billion.

The correct answer is B, Tendulkar Committee. The expert group headed by Suresh Tendulkar, which reported in 2009, recommended measuring poverty through MPCE on the Mixed Reference Period. Under this method, spending on five rarely bought items, namely clothing, footwear, durable goods, education and institutional medical care, is recorded over the last 365 days, and all other items over the last 30 days. Tendulkar also moved away from the old calorie norm and used one poverty line basket for rural and urban India, covering spending on health and education. By this method, India's poverty ratio came to 21.9 per cent in 2011-12. A is wrong, because the Lakdawala group of 1993 used the Uniform Reference Period and state-wise poverty lines. C is wrong, because the Dandekar and Rath study of 1971 based poverty on an intake of 2,250 calories a day. D is wrong, because the Alagh task force of 1979 fixed calorie norms of 2,400 rural and 2,100 urban. Exam tip: Alagh 1979 calories, Lakdawala 1993 URP, Tendulkar 2009 MRP, Rangarajan 2014.

The correct answer is A, crowding out. When the government runs a deficit, it borrows heavily from the same pool of savings that private firms use, so interest rates rise and private investment falls. This squeezing out of private spending by public borrowing is called the crowding out effect. It is the main argument against high fiscal deficits: if the state absorbs most of the savings, businesses find loans costlier and invest less, and the boost from government spending is partly cancelled. It is also why India's fiscal rules, such as the FRBM Act, 2003, aim to keep the deficit in check. B is wrong, because crowding in is the opposite, when public spending on roads, ports and the like encourages more private investment. C is wrong, because pump priming means government spending during a slump to restart demand, not the fall in private investment. D is wrong, because dumping is selling exports abroad below their home price or cost, a trade issue met with anti-dumping duty. Exam tip: deficit borrowing, higher interest rates, less private investment; that is crowding out.

The correct answer is C, Sikkim. Tsomgo Lake, also called Changu Lake, lies in East Sikkim, about 40 km from Gangtok on the road to Nathu La. It is a glacial lake at a height of roughly 3,750 metres; it freezes in winter and is fed by melting snow in summer, which makes it one of Sikkim's best-known tourist spots. In the local language tso means lake, the same word you see in the names of Ladakh's lakes. Nathu La, the pass just beyond it, is a point for border trade with the Tibet region of China. A is wrong, because Ladakh's famous high lakes are Pangong Tso and Tso Moriri, not Tsomgo. B is wrong, because Himachal Pradesh is known for lakes such as Chandratal and Suraj Tal. D is wrong, because Uttarakhand's lakes include Nainital, Bhimtal and the mysterious Roopkund. Exam tip: Tsomgo (Changu) and Gurudongmar are Sikkim lakes; Pangong Tso and Tso Moriri are in Ladakh.

The correct answer is C, Bhabar. When rivers leave the Himalayas and reach the plains, their speed drops suddenly and they drop the heaviest load first, pebbles and boulders, in the Bhabar belt. The Bhabar is a narrow strip about 8 to 16 km wide that runs along the foot of the Shiwaliks from the Indus to the Tista. The ground is so porous that most streams sink underground and seem to disappear here. South of it, the water comes up again and creates the wet, marshy Terai, once covered by thick forests full of wildlife. A is wrong, because Khadar is the newer, fine alluvium of the flood plains, renewed almost every year by floods. B is wrong, because Bhangar is the older alluvium on higher ground above flood level, with lime nodules called kankar. D is wrong, because the Terai lies below the Bhabar and has fine, damp soil where the lost streams re-emerge, not boulders. Exam tip: from the hills down, Bhabar (boulders, streams vanish), Terai (streams return, marshy), then Bhangar old and Khadar new alluvium.

The correct answer is D, Krishna and Tungabhadra. Going south from Gulbarga you first cross the Krishna and then reach the Tungabhadra, on whose south bank Hampi stands. The land between these two rivers is the Raichur Doab, a fertile tract that the Bahmani Sultanate and the Vijayanagara Empire fought over for nearly two centuries. Gulbarga, now Kalaburagi, was the first Bahmani capital from 1347, while Hampi was the capital of Vijayanagara, founded in 1336. The Tungabhadra is itself a tributary of the Krishna and joins it further east, near Kurnool. A is wrong, because the Narmada flows far to the north through central India, and the Godavari also lies north of Gulbarga. B is wrong, because the Mahanadi drains Chhattisgarh and Odisha, far from this region. C is wrong, because the Kaveri flows well south of Hampi and the Periyar is a river of Kerala. Exam tip: the Raichur Doab lies between the Krishna and the Tungabhadra; Hampi is on the Tungabhadra.