CDS 2021 Previous Year GK Questions with Answers

The correct answer is A, Structural unemployment. When the jobs on offer need skills, or are in places, that do not match the workers available, people stay jobless even though vacancies exist.

Structural unemployment comes from long-term changes in the economy: new technology, the decline of old industries, or a shift of demand from one region to another. A handloom weaver who loses work to power looms, or a worker in one state while the jobs are in another, cannot simply take the vacancies that exist. It usually lasts longer than other kinds and is reduced by skill training, education and help with moving to where the work is. India's Skill India programme targets this kind of unemployment.

B is wrong: disguised unemployment means more people working on a job than needed, as on small family farms, where removing some does not cut output.

C is wrong: "altered unemployment" is not a recognised type of unemployment.

D is wrong: cyclical unemployment rises and falls with the business cycle, during a recession or slowdown.

Exam tip: skill or place mismatch = structural; recession = cyclical; extra hands on a farm = disguised; between jobs = frictional.

The correct answer is C, 2 only. Graphite has free electrons that can move through it, so it conducts electricity; diamond and fullerene do not conduct well.

In graphite, each carbon atom is bonded to only three others, forming flat sheets of hexagons. The fourth electron of every atom is free to move along the sheets, which lets graphite carry current; that is why it is used for electrodes in dry cells and electric arcs. In diamond, every carbon atom is bonded to four others in a rigid three-dimensional network, leaving no free electrons, so diamond is an insulator even though it conducts heat very well. Fullerene, such as the football-shaped C60, has its electrons held within the molecule and is a poor conductor.

A is wrong: diamond is an electrical insulator.

B is wrong: it includes diamond, which does not conduct electricity.

D is wrong: neither diamond nor fullerene is a good conductor, and it leaves out graphite.

Exam tip: graphite is the only common non-metal that conducts electricity; diamond is the hardest natural substance.

The correct answer is C. Nominal GDP values each year's output at that year's own (current) prices, not at constant prices, so this statement is not correct.

GDP is the money value of all final goods and services produced within a country in a year. Nominal GDP uses current prices, so it can rise simply because prices have gone up. Real GDP removes this effect by valuing the output of every year at the prices of one base year, which shows the true change in production. The ratio of nominal to real GDP, multiplied by 100, gives the GDP deflator, a broad measure of inflation.

A is correct: valuing different years at common, or base-year, prices is exactly how real GDP is worked out.

B is correct: potential GDP is the output the economy could produce with full employment of labour and capital.

D is correct: real GDP divided by population gives real GDP per capita, a common measure of living standards.

Exam tip: nominal GDP = current prices; real GDP = constant (base-year) prices; deflator = nominal ÷ real × 100.

The correct answer is A, Larger while standing than while lying. The body's weight stays the same, but standing puts it on the small area of the feet, so the pressure is greater.

Pressure is force per unit area: P = F / A. A person's weight is the force, and it does not change with posture. When standing, the weight rests on the soles of the two feet, a small area, so the pressure on the sand is large and the feet sink in. When lying down, the same weight spreads over the whole back, a much larger area, so the pressure falls and the body hardly sinks. This is why camels have broad feet for sand, and why skis and wide tracks are used on snow.

B is wrong: it reverses the effect; a smaller contact area gives a larger pressure.

C is wrong: the force is the same, but the area changes, so the pressure cannot stay the same.

D is wrong: the time of day has no effect on pressure; only force and area matter.

Exam tip: same force, smaller area means more pressure: sharp knives, nails and narrow heels.

The correct answer is B, Au, that is gold. Malleability is the property of being beaten into thin sheets and ductility the property of being drawn into wires, and gold possesses both to the highest degree of any metal: a single gram can be beaten into a sheet of about one square metre and drawn into a wire of great length, which is why gold leaf and gold wire have been made for centuries. Option A is wrong because sodium is so soft that it can be cut with a knife and is reactive enough to be stored under kerosene, so it cannot be drawn into a usable wire. Option C is wrong because cerium, a lanthanide used in lighter flints and alloys, is brittle and not valued for either property. Option D is wrong because mercury is the only metal that is liquid at room temperature, and a liquid can be neither beaten into sheets nor drawn into wires.

The correct answer is B, 1833. The Charter Act of 1833 ended the East India Company's last trading privilege, its monopoly over trade with China and in tea, and turned the Company into a purely administrative body holding India in trust for the British Crown. Pressure from British free-trade manufacturers, who wanted open access to Asian markets, forced the change. The same Act made the Governor-General of Bengal the Governor-General of India, with Lord William Bentinck the first to hold the title, centralised legislative power in his council and declared that no Indian was to be barred from office on grounds of religion, birth, descent or colour. Option A is wrong because the Charter Act of 1813 ended the monopoly on Indian trade but expressly kept the China and tea monopoly. Option C is wrong because 1838 saw no charter legislation. Option D is wrong because Company rule itself had ended in 1858 under the Government of India Act. Exam tip: 1813 Indian trade opened, 1833 China and tea monopoly ended, 1853 civil services opened to competition.

The correct answer is A, Punjab. The south-west monsoon splits over the sea into two arms, and Punjab is one of the few places where both reach. The Arabian Sea branch crosses the Western Ghats, travels north over Gujarat and Rajasthan and arrives in Punjab from the south-west. The Bay of Bengal branch enters through the Ganga plain, is turned west by the Himalayas and sweeps up the plain to Punjab and Haryana, where the two streams meet. Because both arms have already lost most of their moisture by then, Punjab gets only about 50 centimetres of monsoon rain, and the north-west is the last region the monsoon reaches, usually in early July. Option B is wrong because Maharashtra is fed by the Arabian Sea branch alone. Option C is wrong because Meghalaya and the Cherrapunji hills are watered only by the Bay of Bengal branch. Option D is wrong because interior Tamil Nadu lies in a rain shadow in summer and depends on the retreating north-east monsoon. Exam tip: Punjab and Haryana are where the two monsoon branches meet.

The correct answer is B, mitochondria and plastids. Both carry a small circular DNA of their own and their own 70S ribosomes, so they make a part of their protein themselves and divide independently of the cell; this semi-autonomous nature is the main evidence for the view that they descend from free-living bacteria engulfed by an early cell. Option A is wrong because the Golgi body and the endoplasmic reticulum are membrane systems that modify and transport material and carry no genetic matter of their own; the rough endoplasmic reticulum merely holds ribosomes on its outer surface. Option C is wrong because the lysosome is only a sac of digestive enzymes and the Golgi body, as stated, has no DNA. Option D is wrong because the vacuole is a storage sac bounded by the tonoplast and has no DNA, even though its partner in the option, the plastid, does. Remember the pair as the two power organelles of the cell.

The correct answer is C, Telangana. The Kaleshwaram project lifts water from the Godavari near the confluence of the Godavari and the Pranahita and carries it through a chain of barrages, pump houses, tunnels and canals to the drier districts of Telangana; it is described as a multi-stage lift irrigation scheme rather than a single storage dam. Option A is wrong because Kerala’s largest irrigation and power works are on the Periyar, such as the Idukki arch dam. Option B is wrong because Gujarat’s major project is the Sardar Sarovar on the Narmada. Option D is wrong because Maharashtra’s best-known works are Koyna on the Koyna river and Ukai lies in Gujarat on the Tapi. For this topic remember the pairing of state, river and type of structure, since that is exactly what the question tests.

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 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 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 C, Samudragupta. The Prayaga Prashasti, better known as the Allahabad Pillar Inscription, is a long Sanskrit poem in his praise. It was composed by Harishena, his court poet and minister, and engraved on an old Ashokan pillar now kept in the Allahabad (Prayagraj) Fort. It lists the kings Samudragupta defeated in the north and the south, the frontier states and forest kingdoms that paid him tribute, and praises him as a poet and a player of the veena, which his coins also show. His wide conquests led the historian V. A. Smith to call him the Napoleon of India. A is wrong, because the same pillar carries Ashoka's own edicts, not a prashasti praising him. B is wrong, because Harshavardhana is praised in Banabhatta's Harshacharita, not in this inscription. D is wrong, because no prashasti at Prayaga praises Bindusara, the Mauryan king who was Ashoka's father. Exam tip: Prayaga Prashasti, Harishena, Samudragupta; Aihole inscription, Ravikirti, Pulakeshin II.

The correct answer is C, Right to Property. The 44th Amendment Act, 1978 removed it from the list of Fundamental Rights. Before 1978, property was protected by Article 19(1)(f) and Article 31. The Janata government repealed both and placed a new Article 300A in Part XII, which says no person shall be deprived of his property save by authority of law. So property is now only a constitutional and legal right: a person can go to a High Court under Article 226, but not straight to the Supreme Court under Article 32. A is wrong, because the Right against Exploitation under Articles 23 and 24 still stands as a Fundamental Right. B is wrong, because the Right to Constitutional Remedies under Article 32 remains; Ambedkar called it the heart and soul of the Constitution. D is wrong, because the Right to Education was added, not removed, as Article 21A by the 86th Amendment of 2002. Exam tip: 44th Amendment, 1978, property moved from Articles 19(1)(f) and 31 to Article 300A.

The correct answer is C, Article 243 D. This Article deals with reservation of seats in Panchayats, including the seats for women. Article 243 D, added by the 73rd Amendment Act, 1992, reserves seats for Scheduled Castes and Scheduled Tribes in proportion to their population, and reserves not less than one-third of the total seats for women, counting women's seats inside the SC and ST quota too. The same one-third rule applies to the offices of chairpersons at every level. Many states, Bihar being the first, have raised the women's share to 50 per cent through their own laws. A is wrong, because Article 243 B deals with the constitution of Panchayats at the village, intermediate and district levels. B is wrong, because Article 243 C covers the composition of Panchayats. D is wrong, because Article 243 E fixes the duration of Panchayats at five years. Exam tip: 243 B set up, 243 C composition, 243 D reservation, 243 E five-year term.