UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
You are in-charge of implementing the Family Planning programme in an area where there is a strong opposition to the present policy. You want to convince the residents of the need for keeping small families. What would be the best way of communicating this message ?
Answer (a) & explanation
(a) and (c) are both correct (UPSC accepted both; no negative marking). Step 1: people strongly oppose the policy, so you must win them over. Step 2: (a) explaining calmly how small families improve health and living standards, and (c) offering incentives to adopt family planning, both give people good reasons to agree. Step 3: (b) late marriage and spacing are related ideas but do not directly address keeping families small. (d) using people who were sterilised may meet the same hostility and does not explain the benefits.
Tip: for these interpersonal items, pick the response that is lawful, honest and fixes the real problem through proper channels. Avoid options that give in to pressure, show favouritism or dodge a decision.
Answer as per the official UPSC answer key.
Consider the following organisms :
- 1. Agaricus
- 2. Nostoc
- 3. Spirogyra
Which of the above is/are used as biofertilizer/biofertilizers?
Answer (b) & explanation
Nostoc only is correct (b). Nostoc is a blue-green alga (cyanobacterium) that fixes atmospheric nitrogen in special cells called heterocysts, so it is used as a biofertiliser in paddy fields, along with Anabaena (2). Item 1 is wrong: Agaricus is an edible mushroom, a fungus that does not fix nitrogen. Item 3 is wrong: Spirogyra is a green alga that does not fix nitrogen. So (a), (c) and (d) fail.
Notice the other biofertilisers: Rhizobium in legume root nodules, free-living Azotobacter and Azospirillum, the Azolla–Anabaena partnership in rice fields, and mycorrhizal fungi that help absorb phosphorus. Biofertilisers are promoted under the National Mission on Natural Farming. Trap: all three are 'lower' organisms, but only one fixes nitrogen.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. The Council of Ministers in the Centre shall be collectively responsible to the Parliament.
- 2. The Union Ministers shall hold the office during the pleasure of the President of India.
- 3. The Prime Minister shall communicate to the President about the proposals for legislation.
Which of the statements given above is/are correct?
Answer (b) & explanation
Statements 2 and 3 are correct per UPSC's key (b). Union ministers hold office during the pleasure of the President (Article 75(2)) (2). The Prime Minister must communicate to the President all decisions of the Council of Ministers and proposals for legislation (Article 78) (3). Statement 1 is treated as wrong because Article 75(3) makes the Council of Ministers collectively responsible to the House of the People (Lok Sabha), not to Parliament as a whole; the Rajya Sabha cannot remove the government. So (a), (c) and (d) fail.
Notice the practice: the President's 'pleasure' is exercised on the PM's advice, so a minister can be dropped only through the PM. A no-confidence motion can be moved only in the Lok Sabha. Trap: 'Parliament' sounds right, but the precise answer is the Lok Sabha.
Answer as per the official UPSC answer key.
Which of the following grants/grant direct credit assistance to rural households?
- 1. Regional Rural Banks
- 2. National Bank for Agriculture and Rural Development
- 3. Land Development Banks
Select the correct answer using the codes given below.
Answer (c) & explanation
Regional Rural Banks and Land Development Banks are correct (c). Regional Rural Banks (1975) lend directly to small farmers, artisans and rural households (1). Land Development Banks, now called Primary Cooperative Agriculture and Rural Development Banks, give long-term loans to farmers for land improvement, wells and machinery (3). Item 2 is wrong: NABARD is an apex development bank that refinances these banks and cooperatives; it does not lend directly to households. So (a), (b) and (d) fail.
Notice the structure: NABARD (1982) was set up on the Shivaraman Committee's advice and manages the RIDF. RRBs are owned by the Centre (50%), sponsor bank (35%) and State (15%), and were amalgamated to 28 from May 2025. Trap: NABARD sounds rural, but it lends to banks, not people.
Answer as per the official UPSC answer key.
Read the passage
Financial markets in India have acquired greater depth and liquidity over the years. Steady reforms since 1991 have led to growing linkages and integration of the Indian economy and its financial system with the global economy. Weak global economic prospects and continuing uncertainties in the international financial markets therefore, have had their impact on the emerging market economies. Sovereign risk concerns, particularly in the Euro area, affected financial markets for the greater part of the year, with the contagion of Greece’s sovereign debt problem spreading to India and other economies by way of higher-than-normal levels of volatility.
The funding constraints in international financial markets could impact both the availability and cost of foreign funding for banks and corporates. Since the Indian financial system is bank dominated, banks’ ability to withstand stress is critical to overall financial stability. Indian banks, however, remain robust, notwithstanding a decline in capital to risk-weighted assets ratio and a rise in non-performing asset levels in the recent past. Capital adequacy levels remain above the regulatory requirements. The financial market infrastructure continues to function without any major disruption. With further globalization, consolidation, deregulation, and diversification of the financial system, the banking business may become more complex and riskier. Issues like risk and liquidity management and enhancing skill therefore assume greater significance.
According to the passage, in the Indian financial system, banks’ ability to withstand stress is critical to ensure overall financial stability because Indian financial system is
Answer (d) & explanation
(d) is correct. Step 1: the passage says: 'Since the Indian financial system is bank dominated, banks' ability to withstand stress is critical to overall financial stability.' So the reason is that banks dominate the system. Step 2: (a) and (c) are wrong: control by the Government or the RBI is not mentioned as the reason. Step 3: (b) is wrong: 'less integrated with banks' contradicts the passage, which says the system is dominated by banks. So (a), (b) and (c) fail.
Tip: words like 'since' and 'because' introduce the reason. When the question repeats a sentence from the passage, find it and read the clause beginning with 'since'; that is your answer.
Answer as per the official UPSC answer key.
Read the passage
Ecological research over the last quarter of the century has established the deleterious effects of habitat fragmentation due to mining, highways and such other intrusions on forests. When a large block of forests gets fragmented into smaller bits, the edges of all these bits come into contact with human activities resulting in the degradation of the entire forests. Continuity of forested landscapes and corridors gets disrupted affecting several extinction-prone species of wildlife. Habitat fragmentation is therefore considered as the most serious threat to biodiversity conservation. Ad hoc grants of forest lands to mining companies coupled with rampant illegal mining is aggravating this threat.
What is the central focus of this passage ?
Answer (d) & explanation
'Disruption of habitat' is correct (d). Step 1: the passage is about habitat fragmentation: mining and highways break forests into bits, edges are degraded, corridors are cut, and this is 'the most serious threat to biodiversity conservation'. Every sentence returns to the disruption of habitat. Step 2: (a) illegal mining is only one cause, mentioned in the last sentence. (b) extinction of wildlife is one effect. Step 3: (c) conservation of nature is too broad: the passage is about one specific threat, not conservation in general. So (a), (b) and (c) fail.
Tip: the central focus is usually the idea linking the cause and the effect. Options naming only a cause or only an effect are too narrow.
Answer as per the official UPSC answer key.
Consider the following statements :
Attorney General of India can
- 1. take part in the proceedings of the Lok Sabha
- 2. be a member of a committee of the Lok Sabha
- 3. speak in the Lok Sabha
- 4. vote in the Lok Sabha
Which of the statements given above is/are correct?
Answer (c) & explanation
Statements 1, 2 and 3 are correct (c). Under Article 88, the Attorney General has the right to speak in (3) and take part in the proceedings of either House (1), any joint sitting, and any committee of which he may be named a member (2). Item 4 is wrong: he is not a Member of Parliament, so he cannot vote. So (a), (b) and (d) fail.
Notice the office: appointed under Article 76, the Attorney General is India's highest law officer, must be qualified to be a Supreme Court judge, and holds office during the President's pleasure. He is not a member of the Cabinet. R. Venkataramani has held the post since October 2022. He enjoys the privileges of an MP (Article 105(4)). Trap: speaking without voting is the key distinction.
Answer as per the official UPSC answer key.
Which of the following diseases can be transmitted from one person to another through tattooing?
- 1. Chikungunya
- 2. Hepatitis B
- 3. HIV-AIDS
Select the correct answer using the codes given below.
Answer (b) & explanation
Hepatitis B and HIV are correct (b). Tattoo needles shared or reused without sterilising can carry blood-borne viruses: Hepatitis B (2), Hepatitis C, and HIV (3). Item 1 is wrong: chikungunya spreads through the bite of infected Aedes mosquitoes (aegypti and albopictus), not through blood contact in tattooing. So (a), (c) and (d) fail.
Notice the prevention: single-use needles, sterilised equipment and fresh ink pots. India's blood banks screen donors for HBV, HCV and HIV and often defer people with recent tattoos for 6–12 months. Hepatitis B has a vaccine in India's Universal Immunisation Programme; HIV and Hepatitis C do not. Trap: chikungunya is a viral disease, but its route is the mosquito.
Answer as per the official UPSC answer key.
In the context of cultural history of India, a pose in dance and dramatics called ‘Tribhanga’ has been a favourite of Indian artists from ancient times till today. Which one of the following statements best describes this pose?
Answer (a) & explanation
Option (a) is correct. Tribhanga means 'three bends': the body bends at the knee, the waist and the neck, alternately in opposite directions, giving a graceful S-shaped curve. It is a signature pose of Odissi dance and is common in sculpture, such as images of Krishna playing the flute. (b) describes aharya and abhinaya in classical theatre. (c) describes dance in general. (d) describes the shringara (erotic) rasa, not a specific pose.
Notice the related poses: Abhanga (slight bend), Samabhanga (straight, balanced) and Atibhanga (exaggerated bend) are described in the Shilpa Shastras. Odissi's other basic stance is the square chowk. The Natya Shastra of Bharata Muni is the oldest text on these arts. Trap: three bends, not three expressions.
Answer as per the official UPSC answer key.
Read the passage
Malnutrition most commonly occurs between the ages of six months and two years. This happens despite the child’s food requirements being less than that of an older child. Malnutrition is often attributed to poverty, but it has been found that even in households where adults eat adequate quantities of food, more than 50 per cent of children-under-five do not consume enough food. The child’s dependence on someone else to feed him/her is primarily responsible for the malnutrition. Very often the mother is working and the responsibility of feeding the young child is left to an older sibling. It is therefore crucial to increase awareness regarding the child’s food needs and how to satisfy them.
According to the passage, malnutrition in children can be reduced
Answer (c) & explanation
(c) is correct. Step 1: the passage ends: 'It is therefore crucial to increase awareness regarding the child's food needs and how to satisfy them.' So malnutrition falls when the food needs of young children are known. Step 2: (a) regular intake sounds good, but the passage blames the lack of awareness of how much a child needs; it does not offer 'regular food' as the remedy. Step 3: (b) is wrong: the problem peaks at six months to two years; waiting until age five is no remedy. (d) is wrong: the passage does not say feeding by adults solves it; even in households where adults eat well, children go hungry. So (a), (b) and (d) fail.
Tip: look for 'therefore' or 'it is crucial'; the solution usually follows.
Answer as per the official UPSC answer key.
Read the passage
The law in many parts of the world increasingly restricts the discharge of agricultural slurry into watercourses. The simplest and often the most economically sound practice returns the material to the land as semisolid manure or as sprayed slurry. This dilutes its concentration in the environment to what might have occurred in a more primitive and sustainable type of agriculture and converts pollutant into fertilizer. Soil microorganisms decompose the organic components of sewage and slurry and most of the mineral nutrients become available to be absorbed again by the vegetation.
The excess input of nutrients, both nitrogen and phosphorus — based, from agricultural runoff (and human sewage) has caused many ‘healthy’ oligotrophic lakes (low nutrient concentrations, low plant productivity with abundant water weeds, and clear water) to change to eutrophic condition where high nutrient inputs lead to high phytoplankton productivity (sometimes dominated by bloom-forming toxic species). This makes the water turbid, eliminates large plants and, in the worst situations, leads to anoxia and fish kills; so called cultural eutrophication. Thus, important ecosystem services are lost, including the provisioning service of wild-caught fish and the cultural services associated with recreation.
The process of cultural eutrophication of lakes has been understood for some time. But only recently did scientists notice huge ‘dead zones’ in the oceans near river outlets, particularly those draining large catchment areas such as the Mississippi in North America and the Yangtze in China. The nutrient-enriched water flows through streams, rivers and lakes, and eventually to the estuary and ocean where the ecological impact may be huge, killing virtually all invertebrates and fish in areas up to 70,000 km² in extent. More than 150 sea areas worldwide are now regularly starved of oxygen as a result of decomposition of algal blooms, fuelled particularly by nitrogen from agricultural runoff of fertilizers and sewage from large cities. Oceanic dead zones are typically associated with industrialized nations and usually lie off countries that subsidize their agriculture, encouraging farmers to increase productivity and use more fertilizer.
According to the passage, why should the discharge of agricultural slurry into watercourses be restricted ?
- 1. Losing nutrients in this way is not a good practice economically.
- 2. Watercourses do not contain the microorganisms that can decompose organic components of agricultural slurry.
- 3. The discharge may lead to the eutrophication of water bodies.
Select the correct answer using the codes given below :
Answer (c) & explanation
1 and 3 are correct (c). Step 1: the passage calls returning slurry to the land 'often the most economically sound practice', which turns 'pollutant into fertilizer'. Dumping it in water wastes these nutrients, so 1 is right. Step 2: the passage shows that nutrients from runoff cause eutrophication of lakes and 'dead zones' in the sea, so 3 is right. Step 3: statement 2 is wrong: the passage talks of soil microorganisms, but never says watercourses lack them. So (a), (b) and (d) fail.
Tip: 'never discussed' is enough to reject a statement. Do not accept a point because it sounds scientific; it must come from the passage.
Answer as per the official UPSC answer key.
Read the passage
It was already late when we set out for the next town, which according to the map was about fifteen kilometres away on the other side of the hills. There we felt that we would find a bed for the night. Darkness fell soon after we left the village, but luckily we met no one as we drove swiftly along the narrow winding road that led to the hills. As we climbed higher, it became colder and rain began to fall, making it difficult at times to see the road. I asked John, my companion, to drive more slowly. After we had travelled for about twenty kilometres, there was still no sign of the town which was marked on the map. We were beginning to get worried. Then without warning, the car stopped and we found we had run out of petrol.
The author asked John to drive more slowly because
Answer (c) & explanation
(c) is correct. Step 1: the passage says 'rain began to fall, making it difficult at times to see the road. I asked John… to drive more slowly.' So the reason was poor visibility. Step 2: (a) is wrong: the road leading to the hills was true all along; the request came only when it became hard to see. Step 3: (b) is wrong: John's driving experience is never mentioned. (d) is wrong: the passage does not say they were in wilderness. So (a), (b) and (d) fail.
Tip: when the cause and the action are in back-to-back sentences, the first usually explains the second. Look for what changed just before the action.
Answer as per the official UPSC answer key.
Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?
Answer (c) & explanation
Mangroves, grasslands, lakes, oceans is correct (c). Mangroves and estuaries are among the most productive ecosystems per unit area, thanks to nutrients from rivers and tides, warmth and sunlight. Grasslands come next, then lakes. The open ocean has the lowest productivity per unit area because surface waters are poor in nutrients, so it is often called a 'watery desert'. (a), (b) and (d) give the wrong order.
Notice the twist: because it is so vast, the ocean still produces about half of the world's total primary production. Other highly productive systems include coral reefs, swamps and tropical rainforests. Productivity is measured as net primary productivity in g/m²/year. Trap: total output and output per area are different measures.
Answer as per the official UPSC answer key.
Consider the following historical places :
- 1. Ajanta Caves
- 2. Lepakshi Temple
- 3. Sanchi Stupa
Which of the above places is/are also known for mural paintings?
Answer (b) & explanation
Ajanta and Lepakshi are correct (b). Ajanta (Maharashtra, about 2nd century BCE to 5th century CE) has India's finest ancient murals, painting Jataka stories, such as the Padmapani Bodhisattva (1). The Lepakshi Veerabhadra temple (Andhra Pradesh, Vijayanagara period, 16th century) has large ceiling murals of epic scenes, and a hanging pillar (2). Item 3 is wrong: Sanchi is famous for stone carvings on its gateways (toranas), not paintings. So (a), (c) and (d) fail.
Notice the others: Bagh caves (MP), Sittanavasal (Tamil Nadu, Jain), Badami and the Brihadeeswara temple's Chola murals. The Hoysala temples and Lepakshi are on UNESCO's lists, with Lepakshi on the Tentative List. Trap: Sanchi is Buddhist art like Ajanta, but in stone.
Answer as per the official UPSC answer key.
Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?
- 1. Dispersion
- 2. Refraction
- 3. Internal reflection
Select the correct answer using the codes given below.
Answer (d) & explanation
All three are correct (d). Sunlight is refracted, or bent, as it enters a raindrop (2), and split into its colours because each wavelength bends differently: dispersion (1). The light is then reflected internally at the back of the drop (3) and refracted again as it leaves. Together, these make a rainbow at about 42° from the point opposite the sun. So options (a), (b) and (c) leave out real processes.
Notice the related facts: a rainbow is seen only with the sun behind you; a secondary rainbow, from two internal reflections, has reversed colours and lies outside the main bow. Red is on the outside of the primary rainbow. Newton used a prism to show dispersion. Trap: internal reflection is often forgotten.
Answer as per the official UPSC answer key.
(Same information as the question above.)
If B is selected and Y is rejected, the team will consist of which one of the following groups?
Answer (c) & explanation
A, B, C and X is correct (c). Step 1: Y is rejected, so (d), which includes Y and has only one male (A), is out. Step 2: (a) puts B with W, which is not allowed. (b) puts C with Z, which is not allowed. Step 3: (c) A, B, C and X breaks no rule: X has no restrictions, and B, C are not paired with W or Z. It also has three males, meeting the 'at least 2 males' rule. So (a), (b) and (d) fail.
Tip: in team questions with ready options, test each option against every rule. One broken rule rules it out. This is often faster than building the team from scratch.
Answer as per the official UPSC answer key.
Consider the following matrix:
| 3 | 370 | 7 |
|---|---|---|
| 2 | 224 | 6 |
| 1 | 730 | X |
What is the number at 'X' in the above matrix?
Answer (c) & explanation
1. Row 1: 3 × 3 × 3 = 27 and 7 × 7 × 7 = 343. 27 + 343 = 370, the middle number.
2. Row 2: 2 × 2 × 2 = 8 and 6 × 6 × 6 = 216. 8 + 216 = 224. The rule holds.
3. Row 3: 1 + (X × X × X) = 730, so X × X × X = 729 = 9 × 9 × 9.
4. X = 9.
Answer as per the official UPSC answer key.
You are a teacher in a University and are setting a question paper on a particular subject. One of your colleagues, whose son is preparing for the examination on that subject, comes to you and informs you that it is his son’s last chance to pass that examination and whether you could help him by indicating what questions are going to be in the examination. In the past, your colleague had helped you in another matter. Your colleague informs you that his son will suffer from depression if he fails in this examination. In such circumstances, what would you do?
Answer (b) & explanation
(b) and (c) are both correct (UPSC accepted both; no negative marking). Step 1: a colleague asks you to leak exam questions for his son. This would break the trust placed in you as a paper-setter. Step 2: (b) politely refusing, and (c) refusing while explaining that it would violate the university's trust, both protect the exam's fairness. Step 3: (a) helping him because he once helped you is a serious breach of duty. (d) reporting him at once is harsher than a first, emotional request needs; a clear refusal is enough.
Tip: for these interpersonal items, pick the response that is lawful, honest and fixes the real problem through proper channels. Avoid options that give in to pressure, show favouritism or dodge a decision.
Answer as per the official UPSC answer key.
Which of the following adds/add nitrogen to the soil?
- 1. Excretion of urea by animals
- 2. Burning of coal by man
- 3. Death of vegetation
Select the correct answer using the codes given below.
Answer (c) & explanation
Items 1 and 3 are correct (c). Animals excrete urea in urine (1), and dead vegetation decays (3); in both cases decomposers convert the nitrogen into ammonia and then nitrates in the soil (ammonification and nitrification). Item 2 is the doubt: burning coal releases nitrogen oxides into the air, and these can reach the soil through acid rain, so some argue it adds nitrogen indirectly; UPSC's key does not count it. So (a), (b) and (d) fail on the key.
Notice the full cycle: fixation by Rhizobium and lightning, nitrification by Nitrosomonas and Nitrobacter, and denitrification by Pseudomonas returning nitrogen to the air. The Haber–Bosch process makes most fertiliser nitrogen. Trap: emissions mainly add nitrogen to the atmosphere, not directly to soil.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. National Development Council is an organ of the Planning Commission.
- 2. The Economic and Social Planning is kept in the Concurrent List in the Constitution of India.
- 3. The Constitution of India prescribes that Panchayats should be assigned the task of preparation of plans for economic development and social justice.
Which of the statements given above is/are correct?
Answer (b) & explanation
Statements 2 and 3 are correct (b). Economic and social planning is Entry 20 of the Concurrent List (2). Article 243G lets State legislatures entrust panchayats with preparing plans for economic development and social justice and implementing schemes, including those in the Eleventh Schedule (3). Statement 1 is wrong: the National Development Council (1952) was a separate body of the PM, Union ministers and all Chief Ministers, created by executive resolution; it was not an organ of the Planning Commission, though the Commission served as its secretariat. So (a), (c) and (d) fail.
Notice the change: NITI Aayog (2015) replaced the Planning Commission, and its Governing Council of CMs has effectively replaced the NDC. Panchayats now prepare Gram Panchayat Development Plans. Trap: 'organ' overstates a working link.
Answer as per the official UPSC answer key.