UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
With reference to the Finance Commission of India, which of the following statements is correct ?
Answer (d) & explanation
None of the statements is correct (d). The Finance Commission under Article 280, set up every five years, recommends how the net proceeds of central taxes are shared between the Union and the States (vertical) and among States (horizontal), the principles of grants-in-aid, and measures to strengthen local bodies' finances. (a) is wrong: it does not deal with foreign capital. (b) is wrong: it has no role in distributing funds among PSUs. (c) is wrong: transparency in financial administration is not its job, though the CAG audits accounts.
Notice the current one: the 16th Finance Commission (chair Arvind Panagariya) kept the States' share at 41% for 2026–31. Trap: (c) sounds generic and safe, but it is not the Commission's function.
Answer as per the official UPSC answer key.
Why is the offering of “teaser loans” by commercial banks a cause of economic concern ?
- 1. The teaser loans are considered to be an aspect of sub-prime lending and banks may be exposed to the risk of defaulters in future.
- 2. In India, the teaser loans are mostly given to inexperienced entrepreneurs to set up manufacturing or export units.
Which of the statements given above is/are correct ?
Answer (a) & explanation
Statement 1 only is correct (a). Teaser loans were home loans with a low fixed rate for the first few years, after which the rate reset sharply higher. Borrowers who qualified only at the low rate might default later, a risk similar to sub-prime lending that caused the 2008 US crisis (1). The RBI therefore raised provisioning and risk weights on such loans in 2010–11. Statement 2 is wrong: they were housing loans to individuals, not loans to new entrepreneurs or export units. So (b), (c) and (d) fail.
Notice the wider lesson: lending based on rising house prices rather than repayment capacity creates bubbles. Trap: statement 2 invents a borrower group to make it sound developmental.
Answer as per the official UPSC answer key.
Read the passage
The concept of ‘creative society’ refers to a phase of development of a society in which a large number of potential contradictions become articulate and active. This is most evident when oppressed social groups get politically mobilised and demand their rights. The upsurge of the peasants and tribals, the movements for regional autonomy and self-determination, the environmental movements, and the women’s movements in the developing countries are signs of emergence of creative society in contemporary times. The forms of social movements and their intensity may vary from country to country and place to place within a country. But the very presence of movements for social transformation in various spheres of a society indicates the emergence of a creative society in a country.
What according to the passage are the manifestations of social movements ?
- 1. Aggressiveness and being incendiary.
- 2. Instigation by external forces.
- 3. Quest for social equality and individual freedom.
- 4. Urge for granting privileges and self-respect to disparaged sections of the society.
Select the correct answer using the codes given below :
Answer (c) & explanation
Items 3 and 4 are correct (c). Step 1: list the movements the passage names: upsurges of peasants and tribals, movements for regional autonomy and self-determination, environmental movements and women's movements. Step 2: see what they show. They express a quest for equality and freedom (item 3) and an urge for rights and dignity for disparaged groups (item 4). Step 3: check the others. Item 1, aggressiveness, and item 2, external instigation, are never mentioned. So (a), (b) and (d) fail.
Tip: do not import ideas the passage does not contain. If a word like 'incendiary' or 'external forces' never appears, the item is out.
Answer as per the official UPSC answer key.
A person has only Rs. 1 and Rs. 2 coins with her. If the total number of coins that she has is 50 and the amount of money with her is Rs. 75, then the number of Rs. 1 and Rs. 2 coins are, respectively
Answer (d) & explanation
25 and 25 is correct (d). Step 1: suppose all 50 coins were Rs. 1 coins. That gives only Rs. 50. Step 2: she has Rs. 75, which is Rs. 25 more. Each time a Rs. 1 coin is swapped for a Rs. 2 coin, the total rises by Rs. 1. So there must be 25 Rs. 2 coins. Step 3: the rest, 50 − 25 = 25, are Rs. 1 coins. Check: 25 × 1 + 25 × 2 = 75. So (a), (b) and (c) fail.
Tip: the 'assume all are the cheaper kind' trick solves most two-item coin and ticket problems in seconds. Or just test each option quickly.
Answer as per the official UPSC answer key.
Read the passage
In spring, polar bear mothers emerge from dens with three month old cubs. The mother bear has fasted for as long as eight months but that does not stop the young from demanding full access to her remaining reserves. If there are triplets, the most persistent stands to gain an extra meal and it may have the meal at the expense of others. The smallest of the litter forfeits many meals to stronger siblings. Females are protective of their cubs but tend to ignore family rivalry over food. In 21 years of photographing polar bears, I’ve only once seen the smallest of triplets survive till autumn.
Mother bear
Answer (b) & explanation
Lets the cubs fend for themselves is correct (b). Step 1: the passage says mother bears 'are protective of their cubs but tend to ignore family rivalry over food'. Step 2: so the cubs must compete among themselves for meals: they fend for themselves: (b). Step 3: (a) and (c) are wrong: the strongest cub wins by its own persistence, not because the mother takes sides or picks favourites. (d) is wrong: the smallest cub 'forfeits many meals', so shares are not equal.
Tip: when the passage says 'ignore', the right option shows non-interference. Options that make the mother active are the traps.
Answer as per the official UPSC answer key.
If a tropical rain forest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because
Answer (a) & explanation
The answer is (a). In a tropical rain forest, most nutrients are stored in the living vegetation, not in the soil. Dead matter decomposes and is recycled very fast in the hot, wet climate, and heavy rainfall leaches nutrients out of the thin soil, leaving poor laterite. When the forest is cleared, the nutrients go with the trees, and the remaining soil is too poor to support quick regrowth. Option (b) is wrong because rain forest seeds are not generally of poor viability. Option (c) is wrong because many species grow fast. Option (d) is wrong because the soil is not fertile.
Notice why this matters: slash-and-burn cultivation (jhum in Northeast India) works only with long fallow periods, since cleared land loses fertility within a few years. Deciduous forests, with slower leaching, recover faster. Trap: lush forest does not mean rich soil.
Answer as per the official UPSC answer key.
What is the difference between Bluetooth and Wi-Fi devices ?
Answer (a) & explanation
Option (a) is correct. Bluetooth works in the 2.4 GHz band for short-range personal area networks (PAN), linking devices a few metres apart. Wi-Fi uses 2.4 GHz or 5 GHz (and newer 6 GHz in Wi-Fi 6E/7) for wireless local area networks. (b) is wrong: Bluetooth is not a WLAN technology, and Wi-Fi is a LAN, not a wide-area, technology. (c) is wrong: neither needs line of sight; radio waves pass through walls, unlike infrared remotes. (d) fails because (b) is wrong.
Notice the wider idea: India delicensed the lower 6 GHz band (5925–6425 MHz) for Wi-Fi in 2025. Bluetooth is named after the Danish king Harald Bluetooth. Trap: line of sight belongs to infrared, not Bluetooth.
Answer as per the official UPSC answer key.
Regular intake of fresh fruits and vegetables is recommended in the diet since they are a good source of antioxidants. How do antioxidants help a person maintain health and promote longevity ?
Answer (c) & explanation
They neutralise free radicals is correct (c). Normal metabolism, pollution and smoking produce free radicals, unstable molecules with an unpaired electron that damage cell membranes, proteins and DNA, and are linked to ageing, heart disease and cancer. Antioxidants such as vitamins C and E, beta-carotene and plant polyphenols donate electrons and neutralise them. (a) is wrong: antioxidants do not activate enzymes for vitamin synthesis. (b) is wrong: oxidation of food is how we get energy; it is not wasteful. (d) is wrong: they are not mainly gene activators.
Notice the related idea: this damage is called oxidative stress. Large trials show antioxidant supplements give little benefit, while whole fruits and vegetables do. Trap: (b) misreads 'oxidation' as bad in general.
Answer as per the official UPSC answer key.
Read the passage
Ecosystems provide people with a variety of goods and services; food, clean water, clean air, flood control, soil stabilization, pollination, climate regulation, spiritual fulfilment and aesthetic enjoyment, to name just a few. Most of these benefits either are irreplaceable or the technology necessary to replace them is prohibitively expensive. For example, potable fresh water can be provided by desalinating sea-water, but only at great cost.
The rapidly expanding human population has greatly modified the Earth’s ecosystems to meet their increased requirements of some of the goods and services, particularly food, fresh water, timber, fibre and fuel. These modifications have contributed substantially to human well being and economic development. The benefits have not been equally distributed. Some people have actually been harmed by these changes. Moreover, short-term increases in some ecosystem goods and services have come at the cost of the long-term degradation of others. For example, efforts to increase the production of food and fibre have decreased the ability of some ecosystems to provide clean water, regulate flooding and support biodiversity.
The passage mentions that “some people have actually been harmed by these changes”. What does it imply ?
- 1. The rapid expansion of population has adversely affected some people.
- 2. Sufficient efforts have not been made to increase the production of food and fibre.
- 3. In the short term some people may be harmed, but in the long term everyone will benefit from modifications in the Earth’s ecosystems.
Which of the statement given above is/are correct ?
Answer (a) & explanation
Statement 1 only is correct (a). Step 1: the passage says the rapidly expanding population 'greatly modified' ecosystems, and 'some people have actually been harmed by these changes'. So population-driven change hurt some people: statement 1. Step 2: statement 2 is wrong: the passage says efforts to increase food and fibre were made. Step 3: statement 3 is wrong: the passage warns of 'the long-term degradation' of ecosystems, not long-term benefit for everyone. So (b), (c) and (d) fail.
Tip: when an option promises a happy ending ('everyone will benefit'), check the passage's tone. Here it is a warning, so the optimistic option is out.
Answer as per the official UPSC answer key.
In a group of persons, 70% of the persons are male and 30% of the persons are married. If two-sevenths of the males are married, what fraction of the females is single?
Answer (d) & explanation
2/3 is correct (d). Step 1: take 100 people. Males = 70, females = 30. Married = 30 in total. Step 2: two-sevenths of males are married: 2/7 × 70 = 20 married males. So married females = 30 − 20 = 10. Step 3: single females = 30 − 10 = 20. The fraction of females who are single = 20 ÷ 30 = 2/3. So (a), (b) and (c) fail.
Tip: for percentage puzzles, assume a total of 100. It turns every percentage into a simple number you can add and subtract.
the fraction is of the females, not of the whole group.
Answer as per the official UPSC answer key.
Consider the following :
- 1. Carbon dioxide
- 2. Oxides of Nitrogen
- 3. Oxides of Sulphur
Which of the above is/are the emission/emissions from coal combustion at thermal power plants ?
Answer (d) & explanation
All three are emitted (d). Burning coal in a thermal power plant releases carbon dioxide from its carbon (1). Indian coal contains some sulphur, which burns to sulphur dioxide (3). At the high furnace temperature, nitrogen and oxygen in the air combine to form nitrogen oxides (2). Coal plants also emit fly ash, particulate matter and mercury. So options (a), (b) and (c) leave out real emissions.
Notice the control side: flue gas desulphurisation (FGD) units remove SO₂, low-NOx burners cut nitrogen oxides, and electrostatic precipitators trap fly ash. India's 2015 emission norms required FGD, but the July 2025 notification exempted most Category C plants (about 78%). Coal still supplies over 70% of India's electricity, and India's net-zero target is 2070. Trap: NOx comes from the air, not the coal, but it is still a coal-combustion emission.
Answer as per the official UPSC answer key.
India is home to lakhs of persons with disabilities. What are the benefits available to them under the law ?
- 1. Free schooling till the age of 18 years in government-run schools.
- 2. Preferential allotment of land for setting up business.
- 3. Ramps in public buildings.
Which of the statements given above is/are correct ?
Answer (d) & explanation
All three are correct (d). The Persons with Disabilities Act, 1995, in force in 2011, gave free education up to 18 years in suitable schools (1), preferential allotment of land at concessional rates for business, housing and special schools (2), and barrier-free access such as ramps in public buildings (3). So options (a), (b) and (c) leave out real benefits.
Notice the later law: the Rights of Persons with Disabilities Act, 2016 replaced it, raised recognised disabilities from 7 to 21, raised job reservation from 3% to 4%, kept free education for children with benchmark disability aged 6 to 18, and set accessibility deadlines. The Accessible India Campaign (Sugamya Bharat, 2015) pushes ramps and accessible transport.
Answer as per the official UPSC answer key.
A new optical disc format known as the Blu-ray Disc (BD) is becoming popular. In what way is it different from the traditional DVD ?
- 1. DVD supports Standard Definition video while BD supports High Definition video.
- 2. Compared to a DVD, the BD format has several times more storage capacity.
- 3. Thickness of BD is 2.4 mm while that of DVD is 1.2 mm.
Which of the statements given above is/are correct ?
Answer (b) & explanation
Statements 1 and 2 are correct (b). A Blu-ray disc is read by a blue-violet laser (405 nm) with a shorter wavelength than a DVD's red laser, so data packs more tightly: about 25 GB per layer against 4.7 GB on a DVD. That gives several times more storage (2) and room for High Definition video, while DVD is mainly standard definition (1). Statement 3 is wrong: both discs are 1.2 mm thick; Blu-ray's data layer just sits nearer the surface. So (a), (c) and (d) fail.
Notice the trend: Ultra HD Blu-ray stores up to 100 GB for 4K video, but streaming has largely replaced discs. Trap: '2.4 mm' doubles the real thickness.
Answer as per the official UPSC answer key.
The Jain philosophy holds that the world is created and maintained by
Answer (a) & explanation
Universal Law is correct (a). Jainism denies a creator God. It holds that the universe is eternal, uncreated, and runs by its own universal law: the natural working of its six substances (soul, matter, space, time, motion, rest) and the law of karma. (b) and (c) are vague terms that do not express this idea. (d) is wrong: a single 'Universal Soul' (Brahman) belongs to Upanishadic and Vedantic thought; Jainism instead believes in countless individual souls (jivas).
Notice the related ideas: Jain ethics rest on the three jewels (right faith, right knowledge, right conduct) and the five vows led by ahimsa; knowledge is many-sided (anekantavada). Buddhism, too, avoids a creator God. Trap: 'Universal Soul' sounds Indian but is Vedantic.
Answer as per the official UPSC answer key.
Read the passage
A country under foreign domination seeks escape from the present in dreams of a vanished age, and finds consolation in visions of past greatness. That is a foolish and dangerous pastime in which many of us indulge. An equally questionable practice for us in India is to imagine that we are still spiritually great though we have come down in the world in other respects. Spiritual or any other greatness cannot be founded on lack of freedom and opportunity, or on starvation and misery. Many western writers have encouraged that notion that Indians are other-worldly. I suppose the poor and unfortunate in every country become to some extent other-worldly, unless they become revolutionaries, for this world is evidently not meant for them. So also subject peoples.
As a man grows to maturity he is not entirely engrossed in, or satisfied with, the external objective world. He seeks also some inner meaning, some psychological and physical satisfactions. So also with peoples and civilizations as they mature and grow adult. Every civilization and every people exhibit these parallel streams of an external life and an internal life. Where they meet or keep close to each other, there is an equilibrium and stability. When they diverge conflict arises and the crises that torture the mind and spirit.
The passage thematically centres on
Answer (a) & explanation
The state of mind of oppressed people is correct (a). Step 1: the passage begins with a country under foreign domination escaping into dreams of past greatness. Step 2: it then explains how the poor and subject peoples turn other-worldly, and ends with the conflict that tortures 'the mind and spirit'. All of this is about how oppressed people think and feel. Step 3: check the others. (b) starvation and misery is one cause mentioned, not the theme. (c) the growth of civilisation appears only as a comparison. (d) is too general; the passage is about oppressed people, not people in general. So (b), (c) and (d) fail.
Tip: the theme should cover the beginning, middle and end of the passage. A word that appears once is usually a detail.
Answer as per the official UPSC answer key.
(Same information as the question above.)
How many males were undecided?
Answer (a) & explanation
31 is correct (a). Step 1: everyone who was undecided = total − against − for = 2,878 − 1,226 − 1,425 = 227. Step 2: 196 of the undecided were females. Step 3: so undecided males = 227 − 196 = 31. Check with the male row: males for = 1,425 − 600 = 825; 825 + 796 + 31 = 1,652. It matches. So (b), (c) and (d) fail.
Tip: always check your answer with a second route through the table. If the row and column totals agree, you are right.
Answer as per the official UPSC answer key.
A rapid increase in the rate of inflation is sometimes attributed to the “base effect”. What is “base effect” ?
Answer (c) & explanation
The answer is (c). Inflation is usually measured as the percentage rise in prices over the same month of the previous year. The base effect is the impact that last year's price level (the base) has on this calculation. If prices were unusually low last year, even a normal rise this year shows up as high inflation; if prices were unusually high last year, this year's inflation looks low. Options (a) and (b) describe real causes of inflation (supply shocks and demand surges), not the statistical base effect, and (d) is wrong because (c) fits.
Notice how often it appears: during 2021, inflation figures looked high partly because prices had crashed during the 2020 lockdown, a classic base effect. The RBI often cites favourable or unfavourable base effects in policy statements. Trap: the base effect is about arithmetic, not new price pressures.
Answer as per the official UPSC answer key.
Consider the following :
- 1. Right to education.
- 2. Right to equal access to public service.
- 3. Right to food.
Which of the above is/are Human Right/Human Rights under “Universal Declaration of Human Rights” ?
Answer (d) & explanation
All three are human rights under the UDHR (d). The Universal Declaration of Human Rights, adopted by the UN General Assembly on 10 December 1948, lists the right of equal access to public service (Article 21), the right to a standard of living adequate for health and well-being, including food (Article 25), and the right to education (Article 26). So options (a), (b) and (c) leave out real rights.
Notice the wider frame: 10 December is Human Rights Day. The UDHR is not a treaty, but its rights were made binding through the two 1966 Covenants (ICCPR and ICESCR). India's own Right to Education (Article 21A, 2002) and the National Food Security Act, 2013 echo these rights.
Answer as per the official UPSC answer key.
An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth
Answer (d) & explanation
Option (d) is correct. A satellite is always 'falling' towards Earth, but it moves sideways so fast that it keeps missing it. Earth's gravity supplies the centripetal acceleration that bends its straight path into a circle. (a) is wrong: gravity certainly exists in orbit; at the ISS height it is still about 90% of surface gravity. (b) is wrong: the Moon's pull is tiny and does not cancel Earth's. (c) is wrong: gravity provides acceleration towards the centre, not the forward speed; the speed comes from the launch.
Notice the numbers: a low Earth orbit needs about 7.8 km/s; a geostationary satellite at about 35,786 km circles once in 24 hours. Astronauts float because they are in free fall, not because gravity is absent.
Answer as per the official UPSC answer key.
Read the passage
The concept of ‘creative society’ refers to a phase of development of a society in which a large number of potential contradictions become articulate and active. This is most evident when oppressed social groups get politically mobilised and demand their rights. The upsurge of the peasants and tribals, the movements for regional autonomy and self-determination, the environmental movements, and the women’s movements in the developing countries are signs of emergence of creative society in contemporary times. The forms of social movements and their intensity may vary from country to country and place to place within a country. But the very presence of movements for social transformation in various spheres of a society indicates the emergence of a creative society in a country.
With reference to the passage, consider the following statements :
- 1. To be a creative society, it is essential to have a variety of social movements.
- 2. To be a creative society, it is imperative to have potential contradictions and conflicts.
Which of the statements given above is/are correct ?
Answer (c) & explanation
Both statements are correct (c). Step 1: the passage says 'the very presence of movements for social transformation in various spheres' indicates a creative society. So a variety of social movements is essential: statement 1 follows. Step 2: the definition itself rests on 'potential contradictions becom[ing] articulate and active'. Without contradictions and conflicts, there is no creative society: statement 2 follows. Step 3: since both come straight from the definition, options (a), (b) and (d) fail.
Tip: when a passage defines a term, every key part of the definition becomes a necessary condition. Check each statement against those parts.
Answer as per the official UPSC answer key.