Railway 2024 Previous Year GK Questions with Answers

The correct answer is B, Producers. Producers, the green plants and algae, are the most numerous living part of an ecosystem because every other organism depends on them for food. They make their own food by photosynthesis using sunlight, so they form the first trophic level of every food chain. Only about 10 per cent of the energy passes from one level to the next (Lindeman's ten per cent law), so each higher level can support fewer organisms. This gives the upright pyramid of numbers in a grassland: many grass plants, fewer grasshoppers, fewer frogs, and very few snakes and hawks. A is wrong because primary consumers, the herbivores, feed on producers and are fewer than them. C is wrong because secondary consumers, the small carnivores, are fewer still. D is wrong because tertiary consumers, the top carnivores such as the tiger or eagle, are the fewest of all. Exam tip: Producer → primary consumer → secondary consumer → tertiary consumer; about 90 per cent of energy is lost at each step; in a single-tree ecosystem the pyramid of numbers is inverted.

The correct answer is D, Heating effect. An iron, toaster, oven, kettle and heater all turn electrical energy into heat when current flows through a coil of high resistance. This is explained by Joule's law of heating: heat produced H = I²Rt, so the heat grows with the square of the current, with the resistance and with the time. The heating coils are made of nichrome, an alloy of nickel and chromium, because it has high resistance and does not melt or oxidise easily when red hot. The electric fuse and the filament bulb also work on this effect. A is wrong because the chemical effect of current is used in electroplating and in charging batteries. B is wrong because the magnetic effect runs electric bells, fans, motors and electromagnets. C is wrong because the physiological effect is the shock or muscle twitch that current causes in a living body. Exam tip: H = I²Rt; heater coil = nichrome, bulb filament = tungsten, fuse wire = tin-lead alloy with a low melting point.

The correct answer is C, a concave lens of suitable power. A concave lens spreads the light rays slightly before they enter the eye, so the image moves back onto the retina. In myopia, or short-sightedness, a person sees nearby objects clearly but distant objects look blurred. It happens when the eyeball is too long or the eye lens is too curved, so light from far objects meets in front of the retina. Concave lenses have negative power, so spectacles for myopia carry a minus number such as -2.0 D (dioptre). A is wrong because a biconvex lens brings rays together and would make the blur worse. B is wrong because a plain glass plate has no power and does not change where the rays meet. D is wrong because a convex lens corrects hypermetropia, or long-sightedness, in which the image forms behind the retina. Exam tip: Myopia = concave (minus) lens; Hypermetropia = convex (plus) lens; Presbyopia in old age = bifocal lens; Astigmatism = cylindrical lens.

The correct answer is B, Adrenal gland. Adrenaline is made by the adrenal glands, which sit like caps on top of the two kidneys. It is released in fear, anger or sudden danger, so it is called the "fight or flight" hormone. It raises the heartbeat and breathing rate, increases blood sugar and sends more blood to the muscles so that the body can react fast. Adrenaline comes from the inner part of the gland, the adrenal medulla; the outer part, the cortex, makes cortisol and aldosterone. A is wrong because the thyroid gland in the neck makes thyroxine, which controls metabolism and needs iodine. C is wrong because the pineal gland in the brain makes melatonin, which controls the sleep-wake cycle. D is wrong because the pituitary gland makes growth hormone and controls several other glands, so it is called the master gland. Exam tip: Adrenal = adrenaline (emergency hormone), Thyroid = thyroxine (metabolism), Pancreas = insulin (blood sugar), Pituitary = master gland.

The correct answer is A, Buddhism. The Great Stupa at Sanchi, in the Raisen district of Madhya Pradesh, is one of the oldest Buddhist monuments in India. It was first built by the Mauryan emperor Ashoka in the 3rd century BCE as a brick mound over relics of the Buddha, and was later enlarged with a stone casing. Four richly carved gateways, or toranas, were added around the 1st century BCE; they show Jataka tales and scenes from the Buddha's life, in which the Buddha himself appears only through symbols such as the Bodhi tree, a wheel or footprints. The Buddhist Monuments at Sanchi became a UNESCO World Heritage Site in 1989. B is wrong because the stupa is not a Hindu shrine; famous Hindu temple sites include Khajuraho and Konark. C is wrong because famous Jain sites include Dilwara and Shravanabelagola. D is wrong because famous Islamic monuments include the Qutub Minar and the Jama Masjid. Exam tip: Sanchi stupa = Ashoka = Buddhism = Madhya Pradesh = UNESCO 1989.

The correct answer is B, Qualification for membership of Parliament. Article 84 lists who can become a Member of Parliament. A candidate must be a citizen of India, must make an oath or affirmation in the form set out in the Third Schedule before a person authorised by the Election Commission, must be at least 30 years old for the Rajya Sabha and at least 25 for the Lok Sabha, and must meet any other qualification that Parliament lays down by law. Parliament did this through the Representation of the People Act, 1951, which also requires the candidate to be a registered voter. A is wrong because disqualifications for membership are in Article 102, with defection covered by the Tenth Schedule. C is wrong because the Annual Financial Statement, or Union Budget, is Article 112. D is wrong because the President's power to issue ordinances is Article 123. Exam tip: 84 qualifications, 102 disqualifications, 112 Budget, 123 ordinance; minimum age 25 for Lok Sabha and 30 for Rajya Sabha.

The correct answer is C, 7th Constitutional Amendment Act. The 7th Amendment of 1956 allowed Parliament to set up a common High Court for two or more states, or for states and a union territory, a power now found in Article 231. It was the amendment that gave effect to the reorganisation of states on a linguistic basis: it abolished the old Part A, B, C and D classes of states and replaced them with states and union territories. Common High Courts still work today; for example, the Gauhati High Court serves Assam, Nagaland, Mizoram and Arunachal Pradesh, and the Punjab and Haryana High Court sits at Chandigarh. A is wrong because the 6th Amendment of 1956 dealt with taxes on the inter-state sale of goods. B is wrong because the 8th Amendment of 1960 extended the reservation of seats for SCs, STs and Anglo-Indians. D is wrong because the 9th Amendment of 1960 gave effect to the transfer of Berubari to Pakistan under the Nehru–Noon agreement. Exam tip: 7th Amendment 1956 = states reorganised + common High Court (Article 231).

The correct answer is A, Article 20. Article 20 gives protection in respect of conviction for offences, and it contains exactly these three safeguards. Clause (1) bars ex post facto criminal laws: no one can be punished for an act that was not an offence when it was done, or given a heavier penalty than the law allowed at that time. Clause (2) bars double jeopardy: no one can be prosecuted and punished for the same offence more than once. Clause (3) bars self-incrimination: a person accused of an offence cannot be forced to be a witness against himself. Since the 44th Amendment of 1978, Articles 20 and 21 cannot be suspended even during a national emergency. B is wrong because Article 21 protects life and personal liberty. C is wrong because Article 19 gives the six freedoms, such as speech and movement. D is wrong because Article 23 bans human trafficking and forced labour (begar). Exam tip: Article 20 = three shields: ex post facto, double jeopardy, self-incrimination; Articles 20 and 21 survive an emergency.

The correct answer is C, Mizoram. The NCERT Class 11 geography book describes Mizoram as the 'Molassis basin', made up of soft, unconsolidated deposits. Molasse is a geologists' word for soft sediments washed down from rising mountains and laid down in a basin; in Mizoram these young rocks were later folded into the north–south ridges of the Purvanchal hills that run along India's eastern border. Because the rocks are soft, the hills of Mizoram are prone to landslides in the monsoon. The Purvanchal also includes the Patkai hills, the Naga hills and the Manipur hills, and the Barak is an important river of Manipur and Mizoram. A is wrong because Tripura is not the state given this name. B is wrong because Assam is mostly the flat Brahmaputra valley. D is wrong because the Meghalaya plateau, with the Garo, Khasi and Jaintia hills, is an old block of hard rock that belongs to the Peninsular plateau. Exam tip: NCERT line: Mizoram = 'Molassis basin'; Meghalaya = detached part of the Peninsular plateau.

The correct answer is D, Brahmaputra river. National Waterway 2 is the Brahmaputra from Dhubri to Sadiya in Assam, a stretch of 891 km declared in 1988. It carries cargo and passengers through the Brahmaputra valley and connects with Bangladesh through the Indo-Bangladesh Protocol route. National Waterway 1, the Ganga–Bhagirathi–Hooghly system from Haldia to Prayagraj, is the longest at 1,620 km. The waterways are developed and run by the Inland Waterways Authority of India, headquartered at Noida. A is wrong because the West Coast Canal with the Champakara and Udyogmandal canals in Kerala is National Waterway 3. B is wrong because the East Coast Canal with the Matai river, in Odisha and West Bengal, is part of National Waterway 5. C is wrong because the Kakinada canal belongs to National Waterway 4, which links the Godavari and Krishna rivers with canals from Kakinada to Puducherry. Exam tip: NW-1 Ganga (Haldia–Prayagraj), NW-2 Brahmaputra (Dhubri–Sadiya), NW-3 West Coast Canal (Kerala).

The correct answer is C, 2, 1, 4, 3. Going from north to south, the order is Aravalli, Vindhya, Satpura and then Ajanta. The Aravalli Range runs across Rajasthan in the north-west and is among the oldest fold mountains in the world. South of it, the Vindhya Range stretches across central India and marks the northern edge of the Narmada valley. The Narmada flows west through a rift valley between the Vindhyas and the Satpura Range, and the Tapi flows along the southern side of the Satpura. The Ajanta Range, famous for the Ajanta caves, lies further south in Maharashtra, between the Tapi and Godavari basins. A is wrong because it puts Ajanta north of Satpura. B is wrong because it places Vindhya north of Aravalli. D is wrong because it makes both of those mistakes. Exam tip: Aravalli → Vindhya → (Narmada) → Satpura → (Tapi) → Ajanta.

The correct answer is D, Mahad Satyagraha. On 20 March 1927 Dr B.R. Ambedkar led thousands of people to the Chavdar Tank at Mahad, in today's Raigad district of Maharashtra, and drank its water to assert the right of Dalits to use public water sources. The Bombay Legislative Council had already resolved in 1923 that such public places be open to all, but upper-caste residents still kept Dalits away. The campaign continued at a second conference in December 1927, where copies of the Manusmriti were publicly burnt. Ambedkar followed it with the Kalaram Temple entry satyagraha at Nashik in 1930. A is wrong because the Shahada Movement was a movement of Bhil tribals in Dhule district in the 1970s. B is wrong because peasant uprisings in the Bombay region, such as the Deccan Riots of 1875, were aimed at moneylenders, not caste barriers. C is wrong because the Kheda Satyagraha of 1918 was Gandhi's campaign in Gujarat for remission of land revenue. Exam tip: Mahad 1927 = water (Chavdar Tank); Kalaram 1930 = temple entry; both led by Ambedkar.

The correct answer is B, Kerala. The Moplah (Mappila) Rebellion of 1921 broke out in the Malabar region of present-day Kerala, which was then a district of the Madras Presidency. The Mappilas were Muslim tenant farmers who had long resented the heavy rents of the mostly Hindu landlords (janmis) and the British officials who backed them. In 1921 the Khilafat and Non-Cooperation movements spread into Malabar, and the unrest turned into an armed revolt led by men such as Variyamkunnath Kunhahammed Haji and Ali Musliyar. The British crushed it with martial law. The most tragic event was the Wagon Tragedy of November 1921, when dozens of Mappila prisoners died of suffocation inside a closed railway goods wagon. A is wrong because the uprising had nothing to do with Assam. C is wrong because Punjab's best-known event of that period is the Jallianwala Bagh massacre of 1919. D is wrong because Bengal is linked to revolts such as the Indigo Revolt of 1859–60. Exam tip: Moplah 1921 = Malabar, Kerala = Khilafat link = Wagon Tragedy.

The correct answer is B, Bombay. The Indian National Congress held its first session in Bombay from 28 to 31 December 1885, at the Gokuldas Tejpal Sanskrit College. Womesh Chunder Bonnerjee presided, 72 delegates from across India attended, and the retired British official A.O. Hume played the key role in organising it. The session had first been planned for Poona but was shifted to Bombay because of a cholera outbreak there. Paper setters also ask about the next few sessions, so link each place with its president. A is wrong because Lahore hosted the famous 1929 session under Jawaharlal Nehru, which adopted the Purna Swaraj resolution. C is wrong because Calcutta hosted the second session in 1886, presided over by Dadabhai Naoroji. D is wrong because Allahabad hosted the fourth session in 1888 under George Yule, the first British president of the Congress. Exam tip: 1885 Bombay, W.C. Bonnerjee, 72 delegates; 1886 Calcutta, Dadabhai Naoroji; 1929 Lahore, Purna Swaraj.

The correct answer is B, acid rain. Rain with a pH below 5.6 is called acid rain. Even clean rain is slightly acidic, with a pH of about 5.6, because carbon dioxide from the air dissolves in it to form weak carbonic acid; that is why 5.6, not 7, is the dividing line. Rain turns more acidic when sulphur dioxide and nitrogen oxides from coal-fired power plants, factories and vehicles mix with water vapour and form sulphuric and nitric acids. Acid rain corrodes marble and metal, kills fish in lakes and harms soil and forests. In India the best-known example is the damage to the Taj Mahal's white marble, often called 'marble cancer'. A is wrong because alkaline rain would have a pH above 7. C is wrong because 'mineral rain' is not a scientific term. D is wrong because hard water means water with dissolved calcium and magnesium salts; it is not a measure of how acidic rain is. Exam tip: rain pH below 5.6 = acid rain; culprits SO₂ and NOₓ; victim marble, as in the Taj Mahal.

The correct answer is C, It protects us from harmful radiation. The ozone layer shields us from the Sun's harmful ultraviolet rays, so when it thins, that protection is lost. It lies in the stratosphere, roughly 15 to 35 km above the Earth, and absorbs most of the UV-B and UV-C radiation. More UV reaching the ground means more skin cancer, cataracts and weaker immunity in people, and damage to crops and to plankton in the sea. The main culprits are chlorofluorocarbons (CFCs), once used in refrigerators, air conditioners and aerosol sprays; a single chlorine atom can destroy thousands of ozone molecules. The Montreal Protocol of 1987 phased these chemicals out. A is wrong because extra UV harms plants and lowers crop yields. B is wrong because ozone loss is about radiation, not the pollution of water. D is wrong because it does nothing to make soil more fertile. Exam tip: ozone layer = Earth's sunscreen in the stratosphere; CFCs damage it; Montreal Protocol 1987; World Ozone Day is 16 September.

The correct answer is D, Forest. A forest forms and runs on its own, without any human effort, so it is a natural ecosystem. Its plants make food by photosynthesis, animals feed on the plants or on one another, and fungi and bacteria break down dead matter and return nutrients to the soil, so the cycle keeps going by itself. Ponds, lakes, grasslands, deserts, rivers and oceans are other natural ecosystems. Ecosystems that people create and have to maintain are called artificial or man-made ecosystems. A is wrong because a crop field is sown, watered, weeded and harvested by farmers. B is wrong because an aquarium is a man-made tank that needs regular cleaning, feeding and aeration. C is wrong because a garden is planted and looked after by people, and left alone it would slowly change into something else. Exam tip: made by nature = natural (forest, pond, desert); made and kept by humans = artificial (crop field, aquarium, garden, park).

The correct answer is B, Na₂CO₃·10H₂O. Washing soda is sodium carbonate decahydrate: each unit of sodium carbonate holds ten molecules of water of crystallisation. It is made from common salt in steps: baking soda is heated to get anhydrous sodium carbonate, called soda ash, which is then recrystallised from water to give washing soda crystals. It is a basic salt used for cleaning, in the glass, soap and paper industries, and to remove the permanent hardness of water. Paper setters like to put these related compounds side by side as options, so learn them together. A is wrong because NaHCO₃ is baking soda (sodium hydrogencarbonate), used in cooking and in antacids. C is wrong because Na₂CO₃ without water is soda ash, not the crystals called washing soda. D is wrong because NaCl is common salt, the starting material for all of these. Exam tip: NaCl → NaHCO₃ (baking soda) → Na₂CO₃ (soda ash) → Na₂CO₃·10H₂O (washing soda).

The correct answer is A, Red light has a longer wavelength and is scattered the least, making it visible from a distance. Red has the longest wavelength in visible light, about 700 nm, so the tiny particles of air, fog, smoke and dust scatter it the least. The light therefore travels far without fading and can be seen from a distance, which is exactly what a danger signal needs. This follows Rayleigh scattering: the shorter the wavelength, the more the light is scattered. The same idea explains why the clear sky looks blue, since blue light is scattered the most, and why the sun looks red at sunrise and sunset. B is wrong because red light is not more reflective than other colours. C is wrong because how easily a colour is produced has nothing to do with its use in signals. D is wrong because looks are not the scientific reason. Exam tip: longest wavelength = least scattering = red for danger; shortest wavelength = most scattering = blue sky.

The correct answer is D, Potassium. The reactivity series lists metals from the most reactive to the least reactive, and potassium heads it because it loses its single outer electron most easily. It reacts so violently with cold water that the hydrogen released catches fire, so potassium is stored under kerosene. The common order is K, Na, Ca, Mg, Al, Zn, Fe, Pb, (H), Cu, Hg, Ag, Au. A metal higher in the list pushes a lower metal out of its salt solution, which is why an iron nail kept in blue copper sulphate solution gets a brown coat of copper. Metals above hydrogen give hydrogen gas with dilute acids; those below it do not. A is wrong because copper lies below hydrogen and does not react with dilute acids. B is wrong because iron sits in the middle of the series. C is wrong because silver is near the bottom, just above gold. Exam tip: top = potassium, bottom = gold; K and Na are kept under kerosene.