UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
Read the passage
Over the next 30 years, many countries are promising to move to net-zero carbon, implying that household emissions will have to be cut to close to nothing. A leading climate scientist reckons that, at best, half the reduction might be achieved through demand-side measures, such as behavioural changes by individuals and households. And even that would require companies and governments to provide more incentives to change through supply-side investments to make low-carbon options cheaper and more widely available.
Which one of the following statements best reflects the central idea conveyed by the passage?
Answer (b) & explanation
The central idea is that low-carbon behaviour can be encouraged through incentives (b). Step 1: the passage says household emissions must fall almost to zero, and at best half can come from changes in people's behaviour. Step 2: even that needs "companies and governments to provide more incentives to change", by making low-carbon options cheaper and widely available. That is (b). Step 3: option (a) says net zero is possible "only" through households, too strong. Option (c) reverses the logic: investment makes low-carbon options cheaper, not the other way. Option (d), subsidies to industry, is not stated.
Tip: look for the "even that would require..." line; it often holds the key. India's Mission LiFE (2022) promotes such climate-friendly lifestyles.
Answer as per the official UPSC answer key.
A question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct option.
Question: In a football match, team P playing against Q was behind by 3 goals with 10 minutes remaining. Does team P win the match?
Statement I: Team P scored 4 goals in the last 10 minutes.
Statement II: Team Q scored a total of 4 goals in the match.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (d) & explanation
Even both statements together are not enough (d). Step 1: with 10 minutes left, P was 3 goals behind. Statement I: P scored 4 more goals. Statement II: Q finished with 4 goals in all. Step 2: Q's score with 10 minutes left could be 3 or 4 (it may or may not have scored again). If Q had 4 then, P had 1, ends with 5: P wins 5–4. If Q had 3 then and scored one more, P had 0, ends with 4: a 4–4 draw. Step 3: both cases fit all the facts, so we cannot say whether P won. Options (a), (b) and (c) fail.
Tip: when one team's late goals are unknown, test the extreme cases. If they give different results, the data is insufficient.
Answer as per the official UPSC answer key.
Consider the following statements :
Statement I : In January, in the Northern Hemisphere, the isotherms bend equatorward while crossing the landmasses, and poleward while crossing the oceans.
Statement II : In January, the air over the oceans is warmer than that over the landmasses in the Northern Hemisphere.
Which one of the following is correct in respect of the above statements?
Answer (a) & explanation
Both are correct and Statement II explains Statement I (a). Statement II is right: in the northern winter (January), land loses heat fast, while the oceans stay warmer, because water heats and cools slowly. Statement I follows: a given temperature line, or isotherm, is pushed south (equatorward) over the cold land and north (poleward) over the warm ocean. Options (b), (c) and (d) miss this link.
Notice the reverse in July: land is hotter, so isotherms bend poleward over land. Warm currents like the Gulf Stream and North Atlantic Drift push isotherms further north, keeping Norway's ports ice-free. In the Southern Hemisphere, with more ocean, isotherms run fairly straight.
Answer as per the official UPSC answer key.
Suppose the revenue expenditure is ₹ 80,000 crores and the revenue receipts of the Government are ₹ 60,000 crores. The Government budget also shows borrowings of ₹ 10,000 crores and interest payments of ₹ 6,000 crores. Which of the following statements are correct?
- I. Revenue deficit is ₹ 20,000 crores.
- II. Fiscal deficit is ₹ 10,000 crores.
- III. Primary deficit is ₹ 4,000 crores.
Select the correct answer using the code given below.
Answer (d) & explanation
All three statements are correct (d). Statement I is right: revenue deficit = revenue expenditure − revenue receipts = 80,000 − 60,000 = ₹20,000 crore. Statement II is right: fiscal deficit = total borrowings = ₹10,000 crore. Statement III is right: primary deficit = fiscal deficit − interest payments = 10,000 − 6,000 = ₹4,000 crore. So options (a), (b) and (c) fail.
Notice the oddity: a fiscal deficit smaller than the revenue deficit simply means non-debt capital receipts, such as disinvestment, covered part of the gap. Primary deficit shows borrowing for needs other than past interest. India's fiscal deficit target is 4.4% of GDP for 2025-26, and the government now aims to cut its debt-to-GDP ratio.
Answer as per the official UPSC answer key.
Who amongst the following are members of the Jury to select the recipient of ‘Gandhi Peace Prize’?
- I. The President of India
- II. The Prime Minister of India
- III. The Chief Justice of India
- IV. The Leader of Opposition in the Lok Sabha
Select the correct answer using the code given below.
Answer (c) & explanation
The PM, CJI and Leader of Opposition are on the jury (c). The Gandhi Peace Prize (from 1995, Ministry of Culture) is chosen by a jury chaired by the Prime Minister (item II). It includes the Chief Justice of India (item III) and the Leader of the largest opposition party in the Lok Sabha (item IV), along with two eminent persons. Item I is wrong: the President is not on it. So options (a), (b) and (d) fail.
Notice the award: ₹1 crore, a citation and a plaque, open to all, regardless of nationality, race or creed. Recent winners include Gita Press (2021), Sheikh Mujibur Rahman (2020) and Sultan Qaboos of Oman (2019). The first went to Julius Nyerere.
Answer as per the official UPSC answer key.
What is the unit digit in the multiplication of 1 × 3 × 5 × 7 × 9 × . . . × 999?
Answer (c) & explanation
The unit digit is 5 (c). Step 1: the product 1 × 3 × 5 × … × 999 has only odd numbers, and one of them is 5. Step 2: any odd number × 5 ends in 5 (for example 3 × 5 = 15, 7 × 5 = 35). Step 3: to end in 0, the product would need a factor 2, and there is none. So the unit digit stays 5. Options (a), (b) and (d) are wrong.
Tip: odd × 5 always ends in 5; even × 5 always ends in 0. Check for 2s and 5s first in unit-digit questions; they decide the answer quickly.
Answer as per the official UPSC answer key.
Read the passage
It is hard to predict how changes in the climate and the atmosphere’s chemistry will affect the prevalence and virulence of agricultural diseases. But there is a risk that such changes will make some plant infections more common in all climatic zones, perhaps catastrophically so. Part of the problem is that centuries of selective breeding have refined the genomes of most high-value crops. They are spectacular at growing in today’s conditions but genetic variations that are not immediately useful to them have been bred out. This is good for yields but bad for coping with changes. A minor disease or even an unknown one could suddenly rampage through a genetically honed crop.
With reference to the above passage, the following assumptions have been made
- I. Global climate change can result in the migration of several plant diseases to new areas.
- II. Scientific understanding of the wild relatives of our present crops would enable us to strengthen food security.
Which of the above assumptions is/are valid?
Answer (c) & explanation
Both assumptions are valid (c). Step 1: the passage says climate change may make plant infections "more common in all climatic zones". So diseases can spread to new areas (I). Step 2: it says useful genetic variety has been bred out of modern crops. That variety still exists in wild relatives of crops, so studying them can help breed hardier crops and protect food security (II). Step 3: both fit the passage's argument. Options (a), (b) and (d) fail.
Tip: wild relatives of crops carry genes for disease and drought resistance. India's National Bureau of Plant Genetic Resources in New Delhi runs one of the world's largest gene banks.
Answer as per the official UPSC answer key.
Consider the following statements :
- I. The Reserve Bank of India mandates all the listed companies in India to submit a Business Responsibility and Sustainability Report (BRSR).
- II. In India, a company submitting a BRSR makes disclosures in the report that are largely non-financial in nature.
Which of the statements given above is/are correct?
Answer (b) & explanation
Only statement II is correct (b). Statement II is right: the Business Responsibility and Sustainability Report (BRSR) asks for disclosures on environment, social and governance (ESG) matters, such as emissions, water, waste, employees and community. These are largely non-financial. Statement I is wrong on two counts: the BRSR is a SEBI requirement (2021), not the RBI's, and it applies to the top 1,000 listed companies by market value, not all listed companies. So options (a), (c) and (d) fail.
Notice BRSR Core, a smaller set of key indicators that needs outside assurance, being phased in for the largest firms. The idea is to stop greenwashing, meaning false claims of being green, and help investors compare companies.
two errors in one line: wrong regulator and "all". Either one is enough to reject it.
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Answer as per the official UPSC answer key.
Consider the following statements :
- I. Carbon dioxide (CO2) emissions in India are less than 0·5 t CO2/capita.
- II. In terms of CO2 emissions from fuel combustion, India ranks second in Asia-Pacific region.
- III. Electricity and heat producers are the largest sources of CO2 emissions in India.
Which of the statements given above is/are correct?
Answer (c) & explanation
Statements II and III are correct (c). Statement II is right: India is second in the Asia-Pacific region in CO₂ emissions from fuel burning, after China, and third in the world. Statement III is right: electricity and heat producers, mainly coal-based power plants, are the largest single source. Statement I is wrong: India emits about 2 tonnes of CO₂ per person, far below the world average of about 4.7 tonnes, but well above 0.5 tonnes. So options (a), (b) and (d) fail.
Notice India's targets: net zero by 2070, 50% of power capacity from non-fossil sources by 2030, a goal already reached in 2025, and cutting emissions intensity of GDP by 45% from 2005 levels.
India's per-capita figure is "low" compared with others, but not as low as 0.5 t.
Answer as per the official UPSC answer key.
The famous female figurine known as ‘Dancing Girl’, found at Mohenjo-daro, is made of
Answer (c) & explanation
The Dancing Girl is made of bronze (c). The Dancing Girl is a small, about 10.5 cm, bronze figure made by the lost-wax (cire perdue) method. Ernest Mackay found it at Mohenjo-daro in 1926. She wears many bangles on her left arm and stands with one hand on her hip. Option (a) is wrong: carnelian was used for beads. Option (b) is wrong: clay was used for terracotta figures and seals. Option (d) is wrong: the figure is not gold.
Notice the other famous finds: the Priest-King bust in steatite, the Pashupati seal, and the Great Bath, all from Mohenjo-daro. The figure is now in the National Museum, New Delhi. Lost-wax casting is still used by Dhokra artisans.
The "Priest-King" from the same site is steatite. Do not swap their materials.
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Answer as per the official UPSC answer key.
Ashokan inscriptions suggest that the ‘Pradeshika’, ‘Rajuka’ and ‘Yukta’ were important officers at the
Answer (b) & explanation
These were district-level officers (b). Rock Edict III asks the yuktas, rajukas and pradeshikas to tour every five years to preach dhamma. Historians read them as district-level officers: the pradeshika a district head, the rajuka a revenue and judicial officer in charge of rural areas, and the yukta a clerk or accounts officer. Options (a), (c) and (d) are wrong: they were not village heads, provincial governors or central ministers.
Notice the other Mauryan officers: Dhamma Mahamattas, created by Ashoka to spread dhamma; kumaras (princes) as provincial governors; and the gramika for villages. The Arthashastra of Kautilya describes a large paid bureaucracy, with officers called adhyakshas heading departments.
Answer as per the official UPSC answer key.
Read the passage
In our country, regrettably, teaching and learning for the examination have been our forte but the new demands of society and the future of work require critical and independent thinking, learning through doing, asking questions from multiple disciplinary perspectives on the same issue, using evidence for building arguments, and reflecting and articulation. Higher education should not “either be a mere servant of the government policy or a passive respondent to public mood.” Higher learning is all about how to think rather than what to think. Teaching has to be re-invented.
Which one of the following statements best reflects the central idea conveyed by the passage?
Answer (d) & explanation
The central idea is that the classroom must be reimagined and teaching re-invented (d). Step 1: the passage says Indian education has focused on exams, but society now needs critical thinking, learning by doing, questioning and evidence-based argument. Step 2: it ends: higher learning is about "how to think rather than what to think. Teaching has to be re-invented." That is (d). Step 3: option (a), lack of resources, is never discussed. Option (b) misreads "not a mere servant of government policy" as "no government control". Option (c), doing away with classrooms, is extreme; the author wants them changed, not removed.
Tip: the last line often states the central idea. The National Education Policy 2020 also stresses critical thinking over rote learning.
Answer as per the official UPSC answer key.
Read the passage
“A network of voluntary associations stands as a ‘buffer’ between the relatively powerless individual and the potentially powerful State.”
Which one of the following statements reflects the best explanation of the above passage?
Answer (c) & explanation
The best explanation is that associations take individuals out of isolation and let them join common efforts (c). Step 1: the passage calls voluntary associations a "buffer" between the "relatively powerless individual" and the "potentially powerful State". Step 2: alone, a person is weak. By joining groups, people act together and gain a voice. That is (c). Step 3: option (a) says the State cannot enforce its will, but the passage calls the State powerful, so (a) reverses it. Options (b) and (d) describe other features of associations, not the buffer idea.
Tip: unpack the metaphor ("buffer") first. Civil society groups like unions, NGOs and cooperatives play this role; Article 19(1)(c) protects the right to form associations.
Answer as per the official UPSC answer key.
Who among the following led a successful military campaign against the kingdom of Srivijaya, the powerful maritime State, which ruled the Malay Peninsula, Sumatra, Java and the neighbouring islands?
Answer (c) & explanation
Rajendra I led the campaign against Srivijaya (c). The Chola king Rajendra I sent a naval expedition around 1025 that sacked Kadaram (Kedah) and other ports of the Srivijaya kingdom. The aim was to protect the sea trade to China. He took the title Kadaram-kondan ("conqueror of Kadaram"), after earlier taking Gangaikondachola for his march to the Ganga. Option (a) is wrong: Amoghavarsha was a Rashtrakuta. Option (b) is wrong: Prataparudra was a Kakatiya. Option (d) is wrong: Vishnuvardhana was a Hoysala. None of these three led overseas raids.
Notice his capital, Gangaikondacholapuram. His father Rajaraja I built the Brihadeshwara temple at Thanjavur and conquered northern Sri Lanka.
Answer as per the official UPSC answer key.
Consider the following statements :
- I. No virus can survive in ocean waters.
- II. No virus can infect bacteria.
- III. No virus can change the cellular transcriptional activity in host cells.
How many of the statements given above are correct?
Answer (d) & explanation
None of the statements is correct (d). Each "no virus" statement is false. Statement I is wrong: seawater is full of viruses, millions in every millilitre; they kill much of the plankton daily and recycle nutrients. Statement II is wrong: bacteriophages are viruses that infect bacteria. Statement III is wrong: viruses routinely take over the host's transcription machinery to make their own proteins. So options (a), (b) and (c) fail.
Notice the medical use of phages: phage therapy is being tried against antibiotic-resistant bacteria, a growing threat called AMR. Viruses are not truly alive outside a host cell. Some viruses, like HPV, can even cause cancer by changing how host genes are switched on.
Answer as per the official UPSC answer key.
Consider the following space missions :
- I. Axiom-4
- II. SpaDeX
- III. Gaganyaan
How many of the space missions given above encourage and support micro-gravity research?
Answer (b) & explanation
Two of the missions support microgravity research (b). Item I is right: Axiom-4 (2025) took Shubhanshu Shukla to the International Space Station, where he ran Indian microgravity experiments, such as on sprouting seeds and muscle loss. Item III is right: Gaganyaan is designed to carry microgravity experiments on its crewed and uncrewed flights. Item II is not counted in UPSC's key: SpaDeX was a docking technology demonstration, though it did carry some small payloads.
Notice SpaDeX's importance: in January 2025 India became the fourth country to dock two satellites in space, after the USA, Russia and China. Docking is needed for the planned Bharatiya Antariksh Station and the Chandrayaan-4 sample return.
Answer as per the official UPSC answer key.
The price (p) of a commodity is first increased by k%; then decreased by k%; again increased by k%; and again decreased by k%. If the new price is q, then what is the relation between p and q?
Answer (a) & explanation
1. Put k = 0. Then the price never changes, so q = p. Check each option: (a) gives p × 10⁸ = q × 10⁸, so p = q. Works. (c) also gives p = q. (b) and (d) fail.
2. To choose between (a) and (c): each "up k%, then down k%" round multiplies the price by (10⁴ − k²) ÷ 10⁴. Example: up 10% and down 10% turns 100 into 99, and (10000 − 100) ÷ 10000 = 0·99.
3. There are two such rounds, so the bracket comes twice (squared) and 10⁴ comes twice (10⁸).
4. Answer: (a).
Answer as per the official UPSC answer key.
Read the passage
Over the next 30 years, many countries are promising to move to net-zero carbon, implying that household emissions will have to be cut to close to nothing. A leading climate scientist reckons that, at best, half the reduction might be achieved through demand-side measures, such as behavioural changes by individuals and households. And even that would require companies and governments to provide more incentives to change through supply-side investments to make low-carbon options cheaper and more widely available.
With reference to the above passage, the following assumptions have been made:
- I. Supply-side investments in companies can result in low-carbon behaviour in people.
- II. People are not capable of adapting low-carbon behaviour without the involvement Government and Companies.
Which of the above assumptions is/are valid?
Answer (a) & explanation
Only assumption I is valid (a). Step 1: the passage says supply-side investments make low-carbon options "cheaper and more widely available", which encourages people to change. So such investments can lead to low-carbon behaviour (I). Step 2: assumption II says people are "not capable" of changing without government and companies. The passage only says incentives help; it never says people cannot change on their own. Step 3: "not capable" overstates it. Options (b), (c) and (d) fail.
Tip: "needs help to do more" is not the same as "cannot do at all". Strong words like "not capable" or "impossible" usually make an assumption invalid.
Answer as per the official UPSC answer key.
A question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct option.
Question: Is (p + q)2 − 4pq, where p, q are natural numbers, positive?
Statement I: p < q.
Statement II: p > q.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (b) & explanation
Either statement alone is enough (b). Step 1: simplify: (p + q)² − 4pq = p² + 2pq + q² − 4pq = (p − q)². Step 2: a square is positive whenever p and q are different, and zero only when p = q. Step 3: statement I (p < q) and statement II (p > q) each say p ≠ q. So each alone answers "yes, it is positive". Options (a), (c) and (d) fail.
Tip: always simplify the expression before reading the statements. (p + q)² − 4pq = (p − q)² is a standard identity worth remembering.
Answer as per the official UPSC answer key.
Consider the following statements :
Statement I : In the context of effect of water on rocks, chalk is known as a very permeable rock whereas clay is known as quite an impermeable or least permeable rock.
Statement II : Chalk is porous and hence can absorb water.
Statement III : Clay is not at all porous.
Which one of the following is correct in respect of the above statements?
Answer (c) & explanation
Only Statement II is correct and it explains Statement I (c). Statement II is right: chalk is porous and its pores connect, so water soaks through it, making it permeable. Statement III is wrong: clay is actually very porous, often holding more water than chalk, but its pores are so tiny that water cannot pass through, which makes it impermeable. So only II explains I, and options (a), (b) and (d) fail.
Notice the key difference: porosity is how much space a rock has for water; permeability is how easily water flows through. Permeable rocks form aquifers that store groundwater, while clay layers act as aquicludes that trap water above or below them, as in artesian wells.
Porous and permeable are not the same. Clay holds water but will not let it through.
Answer as per the official UPSC answer key.