NDA 2023 Previous Year GK Questions with Answers

The correct answer is D, Next to diamond, graphite is the second hardest known substance. Graphite is soft and slippery rather than hard, so this is the statement that is not correct. The difference between the allotropes comes from the way the carbon atoms are joined. In diamond every carbon is bonded to four others in a rigid three dimensional network, which makes it the hardest natural substance. In graphite every carbon is bonded to only three others in flat sheets, and these sheets slide over one another, so graphite is soft enough to serve as a lubricant and as pencil lead. A is correct because the fourth electron of each carbon atom in graphite is free to move, which lets graphite conduct electricity. B is correct because diamond is indeed the hardest known natural substance. C is correct because fullerene, such as the sixty atom buckyball, is a third allotrope of carbon. Exam tip: same element but different structure, so diamond is hard while graphite is soft and conducting.

The correct answer is B, Colloidal solution is homogenous in nature. A colloid only looks uniform to the eye; it is in fact a heterogeneous mixture, so this is the statement that is not true. In a colloid the particles measure between one and one thousand nanometres, large enough to scatter light but too small to be seen or to settle. The two parts of a colloid are called the dispersed phase and the dispersing medium, as in milk, where droplets of fat are spread through water. A true solution such as salt in water is homogeneous and a suspension is plainly heterogeneous, while a colloid lies between the two and is counted as heterogeneous. A is true because the particles do stay spread evenly through the medium. C is true because the scattering of a beam of light by colloidal particles is the Tyndall effect. D is true because the particles are too light to settle under gravity. Exam tip: a true solution is homogeneous while a colloid and a suspension are heterogeneous.

The correct answer is C, Avogadro. The statement in the question is Avogadro's law, given by the Italian scientist Amedeo Avogadro in 1811. It says that equal volumes of all gases at the same temperature and pressure hold the same number of molecules, so the volume of a gas is directly proportional to the number of moles in it. This is why one mole of any gas occupies 22.4 litres at standard temperature and pressure, and why the number of particles in one mole, about 6.022 x 10 to the power 23, is named the Avogadro number after him. A is wrong because Charles law links the volume of a fixed mass of gas to its temperature at constant pressure. B is wrong because Boyle's law says that volume varies inversely with pressure at constant temperature. D is wrong because Gay-Lussac gave the law of combining volumes and the pressure-temperature law. Exam tip: Avogadro ties volume to the number of molecules, Boyle to pressure and Charles to temperature.

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 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.

The correct answer is B, Second Five Year Plan. The Second Plan (1956 to 1961) was built on the model of the statistician P. C. Mahalanobis and aimed at rapid industrialisation with a stress on heavy and basic industries such as steel, machinery and chemicals, on the belief that machines to make machines would speed up growth. The three public sector steel plants at Bhilai, Rourkela and Durgapur, set up with Soviet, German and British help, belong to this plan, and the Industrial Policy Resolution of 1956 gave the public sector the commanding heights of the economy. The plan ran into a foreign exchange crisis and its target growth of 4.5 percent was not fully met. A, the First Plan (1951 to 1956), followed the Harrod-Domar model and gave priority to agriculture, irrigation and power. C, the Fifth Plan (1974 to 1979), focused on poverty removal and self-reliance under the slogan Garibi Hatao. D, the Seventh Plan (1985 to 1990), stressed food, work and productivity. Exam tip: Second Plan means the Mahalanobis model, heavy industry, and Bhilai, Rourkela, Durgapur.

The correct answer is A, 243ZD. Article 243ZD was inserted by the 74th Constitutional Amendment Act of 1992, which added Part IX-A on Municipalities. It requires every state to set up a District Planning Committee in each district to consolidate the plans prepared by the panchayats and the municipalities of the district and to prepare a draft development plan for the district as a whole. At least four-fifths of its members must be elected by and from among the elected members of the district panchayat and the municipalities in the district, in proportion to the rural and urban population, and the chairperson forwards the plan to the state government. B, Article 243ZB, applies the provisions of Part IX-A to Union Territories. C, Article 243ZE, provides for a Metropolitan Planning Committee in every metropolitan area with a population of ten lakh or more. D, Article 243ZC, says that Part IX-A does not apply to the Scheduled Areas and tribal areas under Article 244. Exam tip: remember the run 243ZD district planning, 243ZE metropolitan planning, and that both came with the 74th Amendment of 1992.

The correct answer is A, The Constitution (42nd Amendment) Act. The 42nd Amendment of 1976, passed on the recommendation of the Swaran Singh Committee, added a new Part IV-A with a single Article 51A listing ten Fundamental Duties of citizens, such as respecting the Constitution, the National Flag and the National Anthem, protecting the environment and developing the scientific temper. The idea was taken from the constitution of the former USSR. An eleventh duty, that a parent or guardian must provide education to a child between six and fourteen years, was added by the 86th Amendment of 2002. The duties are not enforceable by courts, but Parliament may make laws to enforce them. B, the 44th Amendment of 1978, undid many Emergency-era changes and made the right to property a legal right. C, the 85th Amendment of 2001, dealt with consequential seniority in promotion for SC and ST employees. D, the 92nd Amendment of 2003, added Bodo, Dogri, Maithili and Santhali to the Eighth Schedule. Exam tip: the 42nd Amendment of 1976 added Part IV-A, Article 51A and ten duties; the 86th Amendment of 2002 made them eleven.

The correct answer is B, Wheat. Western disturbances are low-pressure systems that originate over the Mediterranean Sea and travel eastward with the subtropical westerly jet stream in winter, bringing light rain to Punjab, Haryana, western Uttar Pradesh and Delhi, and snow to the Himalaya, between December and February. Wheat is the main rabi crop, sown in October and November and harvested in March and April, and it needs cool weather and a little rain during its growing period; this winter rain, called mahawat in north India, is described as gold for wheat because it saves a round of irrigation and improves the grain. A, Rice, is a kharif crop that depends on the heavy rain of the south-west monsoon. C, Bajra, is a kharif millet of the dry areas of Rajasthan and Gujarat, grown on monsoon rain. D, Cotton, is also a kharif crop, sown at the start of the monsoon and picked in autumn. Exam tip: western disturbances bring the winter rain of north-west India, which is good for the rabi crops wheat, barley, gram and mustard.

The correct answer is C, Warren Hastings. Warren Hastings was the first Governor-General of Bengal under the Regulating Act of 1773 and held office from 1773 to 1785. After he returned to England, the House of Commons impeached him in 1787 on charges of corruption and misrule, including his treatment of Raja Chait Singh of Banaras and the Begums of Awadh. Edmund Burke led the prosecution, and the trial before the House of Lords ran from 1788 to 1795, ending in his acquittal on every charge. It remains the most famous impeachment in British history. A, Robert Clive, was Governor of Bengal, faced a parliamentary inquiry in 1773 but was never impeached, and died in 1774. B, Henry Vansittart, was Governor of Bengal from 1760 to 1764 and faced no impeachment. D, Lord Cornwallis, succeeded Hastings and is known for the Permanent Settlement of 1793. Exam tip: Hastings, first Governor-General of Bengal, impeached 1787, acquitted 1795.

The correct answer is A, Harishena. The Prayag Prashasti, also called the Allahabad Pillar Inscription, is a Sanskrit eulogy of the Gupta emperor Samudragupta (about 335 to 375 CE) composed by his court poet and minister Harishena, who held the titles sandhivigrahika (minister of peace and war) and kumaramatya. It is engraved on the Ashokan pillar now at Allahabad Fort and lists the kings Samudragupta defeated in the north (uprooted) and in the south (defeated and released), which is why historians call him the Napoleon of India. Written in the champu style, it also describes him as a poet and musician. B, Chand Bardai, wrote the Prithviraj Raso in the twelfth century. C, Vishakhadatta, wrote the play Mudrarakshasa about Chandragupta Maurya and Chanakya. D, Kalidasa, the poet of Abhijnanashakuntalam and Meghaduta, is linked to Chandragupta II, not to this inscription. Exam tip: Harishena, Prayag Prashasti, Samudragupta; Ravikirti, Aihole inscription, Pulakeshin II.

The correct answer is C, Newtonian telescope. Isaac Newton built the first practical reflecting telescope in 1668. In it, light from the star falls on a large concave mirror at the bottom of the tube, and a small flat mirror set at 45 degrees near the top turns the light sideways to the eyepiece. Because the objective is a mirror and not a lens, there is no chromatic aberration, the colour fringing that lenses produce, and a mirror can be made much larger and lighter than a lens. Most big observatory telescopes are therefore reflectors. A, the Galilean telescope, is a refractor using a convex objective lens and a concave eyepiece lens. B, the Keplerian telescope, is also a refractor, with two convex lenses, and gives an inverted image. D, the Schmidt telescope, is a catadioptric design that combines a spherical mirror with a glass corrector plate, so it is not mirrors only. Exam tip: refractor means lenses (Galileo, Kepler), reflector means mirrors (Newton), Schmidt means a mirror plus a corrector lens.

The correct answer is B, A bottle opener. Levers are grouped by where the fulcrum, the load and the effort sit. In a second class lever the load lies between the fulcrum and the effort. In a bottle opener the rim of the cap is the fulcrum at the tip, the cap being lifted is the load in the middle, and your hand applies the effort at the far end. Such levers always multiply force because the effort arm is longer; a wheelbarrow and a nutcracker work the same way. A, A pair of scissors, is a first class lever, with the pivot between the effort and the load. C, A cricket bat, is a third class lever: the lower hand applies the effort between the top hand, which acts as the fulcrum, and the ball. D, A bow and arrow, works by storing energy in the bent bow like a spring, not by placing the load between the fulcrum and the effort. Exam tip: first class has the fulcrum in the middle, second class the load in the middle, third class the effort in the middle.

The correct answer is C, Zinc. Galvanisation is the coating of iron or steel with a thin layer of zinc so that the iron underneath does not rust. Zinc sits above iron in the reactivity series, so even when the coating is scratched, zinc corrodes first and keeps protecting the iron; this is called sacrificial protection. The zinc layer is usually put on by dipping the article in molten zinc (hot-dip galvanising) or by electroplating. Galvanised sheets are used for roofs, water pipes, buckets and electricity poles. A, Gallium, is a rare, low-melting metal and is never used for rust protection. B, Aluminum, forms its own protective oxide layer, but coating iron with aluminium is not called galvanisation. D, Silver, is too costly and is less reactive than iron, so it would not protect it sacrificially. Exam tip: galvanisation means a zinc coating on iron; a tin coating on iron is called tinning.