Defence 2023 Previous Year GK Questions with Answers

The correct answer is D, Polarization. Only a transverse wave can be polarised, so the polarisation of light proves that its vibrations are at right angles to the direction of travel. In ordinary light the electric field vibrates in every plane around the ray. A polaroid sheet lets through only the vibrations in one plane, and a second polaroid turned at ninety degrees then blocks the light completely. A longitudinal wave such as sound, whose particles vibrate along the direction of travel, has no such plane and can never be polarised. Sunglasses, camera filters and LCD screens all use this property. Option A is wrong because refraction, the bending of light on entering a denser medium, happens with sound waves too. Option B is wrong because diffraction, the spreading of a wave at an edge, is shown by all waves. Option C is wrong because interference only proves that light is a wave, not which kind. Exam tip: interference and diffraction prove light is a wave; polarisation proves it is a transverse wave.

The correct answer is Chola Empire. The Sengol is a gold-plated silver sceptre topped by a figure of Nandi. In the Chola tradition, a new king received such a sceptre from a high priest as a symbol of the transfer of power and of the ruler's duty to govern justly. On 14 August 1947 priests from the Thiruvaduthurai Adheenam in Tamil Nadu presented a Sengol to Jawaharlal Nehru, and it was later kept in a museum in Allahabad. On 28 May 2023, when the new Parliament building was inaugurated, it was installed beside the Speaker's chair in the Lok Sabha.

The Pandyan option is the cleverest distractor, because the Pandyas were also a great Tamil dynasty, but the Sengol tradition invoked in 2023 was that of the Cholas. The Gupta and Shunga empires ruled in north India and have no link to it. Questions on the new Parliament building also ask its date of inauguration (28 May 2023) and the first bill passed in it, the Women's Reservation Bill of 2023.

The correct answer is B, light travels much faster than sound. The flash and the clap are produced at the same instant by the same discharge. Light covers about three lakh kilometres in one second, so it reaches the observer almost immediately, while sound in air covers only about 340 metres in a second and takes roughly three seconds for each kilometre. The gap between seeing and hearing is therefore a direct measure of distance.

Option A reverses the true order and would make thunder arrive first, which never happens. Option C is wrong because equal speeds would make the flash and the clap arrive together, with no gap at all. Option D confuses brightness with speed; the flash is indeed very bright, but intensity has nothing to do with why it arrives earlier, and even a faint flash would still be seen before the sound was heard.

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 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, 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 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 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.

The correct answer is D, 1, 2 and 3. All three statements are true. Statement 1: the size of an eruption is rated on the Volcanic Explosivity Index, a scale from 0 to 8 based on the volume of material thrown out and the height of the eruption column; each step up means roughly ten times more material. Statement 2: Iceland sits on the Mid-Atlantic Ridge where two plates move apart, and the Philippines lies on the Pacific Ring of Fire, so both were built by volcanic activity. Statement 3: volcanic ash and lava weather into deep, mineral-rich soils, which is why Java in Indonesia supports dense farming and the Deccan's black soil, formed from basalt lava, grows cotton so well. A is wrong, because it leaves out statement 3, which is true. B is wrong, because it drops statement 1, and the index is the standard measure. C is wrong, because it drops statement 2, though both Iceland and the Philippines are volcanic. Exam tip: VEI runs from 0 to 8; Iceland sits on a ridge, the Philippines on the Ring of Fire; basalt gives black soil.

The correct answer is B, 2 and 6. The Tropic of Cancer crosses eight Indian states, and only two of them touch the sea. Running at about 23.5 degrees north, it passes from west to east through Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram. Gujarat and West Bengal have coastlines, while the other six are landlocked. The line divides India into two nearly equal halves, with the northern part in the temperate zone and the southern part in the tropical zone. A is wrong, because two coastal states, not one, lie on the line, and the total is eight. C is wrong, because 2 and 5 makes only seven states and misses one of the six landlocked ones. D is wrong, because no third coastal state such as Odisha lies on the Tropic; Odisha lies south of it. Exam tip: Tropic of Cancer, eight states from Gujarat to Mizoram; the coastal pair is Gujarat and West Bengal.

The correct answer is D, The Treaty of Salbai. Signed in May 1782 between the East India Company and the Marathas, it ended the First Anglo-Maratha War that had begun in 1775. The war started when the Bombay government backed Raghunathrao's claim to the Peshwa's seat. Mahadji Scindia helped broker the peace at Salbai: the British kept Salsette, recognised the young Madhavrao II as Peshwa, and Raghunathrao was pensioned off. The treaty brought about twenty years of peace between the two powers. A is wrong, because the Treaty of Surat of 1775 between the British and Raghunathrao started the war rather than ending it. B is wrong, because the Treaty of Purandar of 1776, made by the Calcutta council with the Poona ministers, set Surat aside but did not end the fighting. C is wrong, because the Convention of Wadgaon of 1779 was a humiliating surrender by a British force, later rejected by Warren Hastings. Exam tip: Surat 1775 began it, then Purandar 1776 and Wadgaon 1779, and Salbai 1782 ended it.

The correct answer is B, The Battle of Colachel. At Colachel in August 1741, Marthanda Varma of Travancore defeated the Dutch East India Company. It was one of the rare times an Indian ruler decisively beat a European power in open battle, and it ended Dutch hopes of expanding on the Malabar coast. The Dutch commander Eustachius De Lannoy was captured, joined Travancore's service, trained its army on European lines and rose to be its chief commander. Colachel lies on the coast of today's Kanyakumari district in Tamil Nadu. A is wrong, because at Porto Novo in 1781 the British under Eyre Coote defeated Hyder Ali in the Second Anglo-Mysore War. C is wrong, because the battles of Pollilore were fought in 1780 and 1781 between Hyder Ali and the British in that same war. D is wrong, because Changanacherry is a town in central Kerala, not the scene of the 1741 fight with the Dutch. Exam tip: Colachel 1741, Marthanda Varma beat the Dutch; Porto Novo 1781, Eyre Coote beat Hyder Ali.

The correct answer is C, The Estimates Committee. All its 30 members are elected by the Lok Sabha alone, so the Rajya Sabha has no seat on it. The Estimates Committee examines the budget estimates and suggests economies in expenditure, which is why it is called a continuous economy committee. It is the largest financial committee of Parliament; its members are elected every year by proportional representation through the single transferable vote, and a minister cannot be a member. The point that sticks: money matters belong to the Lok Sabha, so the Rajya Sabha is kept out of this one. A is wrong, because the Public Accounts Committee has 22 members, 15 from the Lok Sabha and 7 from the Rajya Sabha. B is wrong, because the Committee on Public Undertakings also has 15 Lok Sabha and 7 Rajya Sabha members. D is wrong, because the committee on SC and ST welfare has 20 Lok Sabha and 10 Rajya Sabha members. Exam tip: Estimates 30, all Lok Sabha; PAC and Public Undertakings, 15 plus 7.

The correct answer is C, The post of the SGI is a constitutional post. It is the one false statement, because the Constitution creates only the Attorney General, not the Solicitor General. Article 76 provides for the Attorney General for India, the chief legal advisor to the Government and the highest law officer. The Solicitor General is the second law officer who assists the Attorney General; the post rests on the Law Officers (Conditions of Service) Rules, 1987, so it is a non-constitutional post. The detail that sticks: only the Attorney General gets an Article number and, under Article 88, the right to speak in both Houses of Parliament. A is a true statement, since the chief legal advisor is the Attorney General, not the SGI. B is true, because the SGI ranks just below the Attorney General as the second law officer. D is true, as the Appointments Committee of the Cabinet appoints the SGI and the Additional Solicitors General. Exam tip: Attorney General, Article 76, constitutional; Solicitor General, no Article, non-constitutional.

The correct answer is D, Shudraka. Mrichchhakatika, The Little Clay Cart, is a ten-act Sanskrit play written by Shudraka, a king-poet of the classical age. Unlike most classical plays about kings and gods, it tells the story of an ordinary poor Brahmin merchant, Charudatta, and his love for the courtesan Vasantasena in the city of Ujjain, with the wicked prince Shakara as villain and a political revolt in the background; the title comes from the toy clay cart of Charudatta's son. It is prized for its realistic picture of city life, thieves, gamblers and courts, and Girish Karnad's film Utsav (1984) is based on it. A, Kalidasa, wrote Abhijnanashakuntalam, Malavikagnimitram, Vikramorvashiyam, Meghaduta and Raghuvamsha. B, Bhasa, wrote Svapnavasavadattam and Charudattam, the shorter play on which Shudraka built his story. C, Valmiki, is the author of the Ramayana, an epic and not a play. Exam tip: Mrichchhakatika by Shudraka, Mudrarakshasa by Vishakhadatta, Ratnavali by Harsha, Svapnavasavadattam by Bhasa.

The correct answer is B, Vairengte. The Counter Insurgency and Jungle Warfare School, known as CIJWS, is at Vairengte in the Kolasib district of Mizoram, close to the Assam border. It trains Indian soldiers in fighting insurgents and in surviving and operating in dense jungle, and its motto is Fight a Guerrilla like a Guerrilla. Soldiers from many friendly foreign armies, including the United States and the United Kingdom, have also trained here, and every army unit going for counter-insurgency duty passes through its courses. A, Dehradun, has the Indian Military Academy, which trains officers before commissioning. C, Gulmarg, in Jammu and Kashmir, has the High Altitude Warfare School, which trains for mountain and snow warfare. D, Mhow, in Madhya Pradesh, has the Infantry School, the Army War College and the Military College of Telecommunication Engineering. Exam tip: jungle warfare at Vairengte in Mizoram, high altitude warfare at Gulmarg, infantry at Mhow, officers at IMA Dehradun and NDA Khadakwasla.

The correct answer is C, 1962. The Battle of Rezang La was fought on 18 November 1962 during the India-China war, at a pass about 16,000 feet high near Chushul in Ladakh. The Charlie Company of 13 Kumaon, 120 men mostly Ahirs from Haryana under Major Shaitan Singh, held the post against repeated Chinese attacks in freezing cold and without artillery support; 114 of them died fighting almost to the last man and the last round. Major Shaitan Singh was awarded the Param Vir Chakra posthumously, and the battle is remembered as one of the greatest last stands in military history. A rebuilt memorial at Rezang La was inaugurated in 2021. A, 1948, falls in the first India-Pakistan war over Kashmir (1947 to 1948), remembered for the tank assault on Zoji La. B, 1956, saw no war fought by India. D, 1972, is the year of the Shimla Agreement, after the 1971 Bangladesh war. Exam tip: Rezang La, 18 November 1962, 13 Kumaon, Major Shaitan Singh, Param Vir Chakra.

The correct answer is A, 1%. Green plants are the producers of a terrestrial ecosystem, and NCERT's Class 10 chapter Our Environment states that they capture about 1 percent of the energy of the sunlight that falls on their leaves and convert it into food energy through photosynthesis. The rest of the sunlight is reflected, passes through the leaf or is lost as heat. This tiny fraction is the base of every food chain, and only about 10 percent of it passes from one trophic level to the next, which is Lindeman's ten percent law; that is why food chains rarely have more than three or four steps and why energy flow in an ecosystem is unidirectional. B, 5%, C, 8%, and D, 10%, are all too high: 10 percent is the share of energy transferred between trophic levels, not the share of sunlight captured by plants, and students often mix up these two numbers. Exam tip: plants capture about 1 percent of sunlight; about 10 percent of energy moves up at each trophic level.

The correct answer is B, Oxygen. A greenhouse gas is one whose molecules absorb the long-wave infrared radiation given off by the warm surface of the Earth and send part of it back, keeping the planet about 33 degrees Celsius warmer than it would otherwise be. Such absorption needs molecules made of three or more atoms, or of two different atoms, that can vibrate in the right way. Oxygen (O2) and nitrogen (N2), which together make up 99 percent of the air, are made of two identical atoms, do not absorb infrared radiation and therefore are not greenhouse gases, even though they are the most abundant gases. A, Water vapour, is the largest natural contributor to the greenhouse effect. C, Carbon dioxide, is the main greenhouse gas added by humans through burning coal, oil and gas, and it is the reference gas for global warming potential. D, Methane, traps about 28 times more heat than carbon dioxide over a century and comes from paddy fields, cattle and landfills. Exam tip: the main greenhouse gases are water vapour, CO2, methane, nitrous oxide, ozone and CFCs; N2 and O2 are not.