UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
Which of the following statements with regard to GenomeIndia Project is/are correct ?
- 1. It is a part of the Human Genome Project.
- 2. The project is funded by the Department of Biotechnology (DBT), Government of India.
- 3. Its primary aim is to build a catalogue of genetic diversity of the Indian population.
Select the answer using the code given below :
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 2 is right: GenomeIndia (2020) is funded by the Department of Biotechnology. Statement 3 is right: it sequenced 10,000 genomes from many Indian communities to build a catalogue of the country's genetic variation, and the data was released in 2025. Statement 1 is wrong: the international Human Genome Project was a separate effort that ended in 2003. So options (a), (c) and (d) fail.
Notice the uses: finding gene variants behind diseases common in India, such as sickle cell and thalassaemia, and building personalised medicine. The data is stored at the Indian Biological Data Centre in Faridabad. A larger follow-up aims to sequence one million genomes.
Answer as per the official UPSC answer key.
‘X’, born in the UK, was conferred the Nobel Prize in 2025. He was a professor in an American university when this prize was announced. Identify X :
Answer (c) & explanation
X is John Clarke (c). John Clarke, born in Cambridge, England, shared the 2025 Nobel Prize in Physics while a professor at the University of California, Berkeley. He won with Michel Devoret and John Martinis for showing macroscopic quantum tunnelling in an electric circuit. Option (a) is wrong: Devoret was born in France. Option (b) is wrong: Richard Robson (Chemistry 2025) was born in England but works in Melbourne, Australia. Option (d) is wrong: Joel Mokyr (Economics 2025) was born in the Netherlands.
Notice why the physics prize matters: their experiments with superconducting circuits in the 1980s laid the base for today's quantum computers. India's own National Quantum Mission (2023) aims to build 50–1,000 qubit machines.
Robson fits "born in the UK" but fails the second clue: his university is in Australia.
Answer as per the official UPSC answer key.
How many words can one form by shuffling the letters of the word QUEUE, if Q is always followed by U? The words thus formed need not necessarily have any meaning.
Answer (d) & explanation
12 words can be formed (d). Step 1: Q must always be followed by U, so tie them together as one block, QU. Step 2: the letters of QUEUE are Q, U, E, U, E. After making the block, we have QU, U, E, E: four items. Step 3: four items can be arranged in 4 × 3 × 2 × 1 = 24 ways. But the two Es are identical, so swapping them gives the same word: 24 ÷ 2 = 12. Options (a), (b) and (c) miss arrangements or divide wrongly.
Tip: "always together" means treat them as one block. Then divide by the factorial of each repeated letter's count.
don't halve again for the Us. One U is inside the block, so the two Us are no longer interchangeable items.
Answer as per the official UPSC answer key.
An explosion takes place at a certain distance from an army camp. As soon as the sensor in the camp receives the sound of the explosion, a drone starts flying towards the spot of explosion. The drone clicks a picture from the spot and the camp receives it at the same time. Immediately another drone starts flying to the spot and it also sends a picture as soon as it reaches the spot. The two pictures were received at 5:02 PM and 5:05 PM, respectively. If the speed of the drones is 30 m/s, at what time did the explosion take place? Assume that the speed of sound is 300 m/s.
Answer (c) & explanation
The explosion happened at 4:58:42 PM (c). Step 1: drone 2 left at 5:02 (when picture 1 arrived) and reached the spot at 5:05. So one flight takes 180 seconds, and the distance = 30 × 180 = 5400 m. Step 2: drone 1 also flew 180 seconds and reached at 5:02, so it left at 4:59:00, the moment the sound reached the camp. Step 3: sound took 5400 ÷ 300 = 18 seconds. So the explosion was at 4:59:00 − 18 s = 4:58:42 PM. Option (a) forgets the sound delay. Options (b) and (d) miscalculate.
Tip: work backwards one step at a time. Pictures arrive instantly, so only flight time and sound travel time matter.
don't stop at 4:59:00. That is when the sound reached the camp, not when the blast happened.
Answer as per the official UPSC answer key.
| List-I (Tool of communication) | List-II (Purpose) |
|---|---|
| A. Memorandum | 1. To record decisions |
| B. Flyer | 2. To inform confidentially |
| C. Bcc | 3. To intimate a directive |
| D. Minutes | 4. To disseminate non-targeted information |
Match List-I with List-II and select the answer using the code given below the Lists :
Answer (c) & explanation
The match is A-3, B-4, C-2, D-1 (c). Step 1: Minutes are the written record of a meeting, so they record decisions (D-1). Step 2: a memorandum (memo) is an internal office note that conveys an instruction, so it intimates a directive (A-3). Step 3: a flyer is handed out to anyone, so it spreads non-targeted information (B-4). Bcc (blind carbon copy) hides recipients from each other, so it informs confidentially (C-2). Options (a), (b) and (d) mismatch.
Tip: know basic office communication terms: memo, circular, minutes, notice and agenda. "Cc" shows all recipients; "Bcc" hides them.
Answer as per the official UPSC answer key.
Which of the following statements with regard to the arrival of Amur Falcons at Doyang Lake in Nagaland each year from Mongolia is/are correct ?
- 1. It showcases how sustained local conservation efforts can contribute to the arrival and protection of international migratory birds.
- 2. It reflects the global success of advanced tracking technologies that guide migratory birds back to their stopover sites.
- 3. It confirms that Amur Falcons have adapted to permanent residency in India due to favourable habitat changes.
Select the answer using the code given below :
Answer (a) & explanation
Only statement 1 is correct (a). Statement 1 is right: around 2012, villages near Doyang in Nagaland, once known for mass hunting of the birds, turned into protectors, so the falcons now roost safely. Statement 2 is wrong: satellite tags only track the birds; they do not guide them. Statement 3 is wrong: Amur falcons stay only a few weeks, so they are not permanent residents. So options (b), (c) and (d) fail.
Notice their journey: they breed in Mongolia, Siberia and northern China, rest in Nagaland, then cross the Arabian Sea to winter in southern Africa, one of the longest raptor migrations. Pangti village is called the "Falcon Capital of the World". Tagged birds have been named after these villages.
Answer as per the official UPSC answer key.
Consider the following statements about Mission Sudarshan Chakra of India :
- 1. It aims to enhance India’s air defence, ballistic missile defence and aerial offensive capabilities.
- 2. This Mission is being designed to enhance rapid, precise, and powerful defence responses, reinforcing India’s strategic autonomy.
- 3. One of the aims of this Mission is to cover all public places of India by an expanded nationwide security shield by 2035.
Which of the statements given above is/are correct ?
Answer (a) & explanation
All three statements are correct (a). The Prime Minister announced Mission Sudarshan Chakra on 15 August 2025. Statement 1 is right: it aims to strengthen air defence, ballistic missile defence and offensive strike capability. Statement 2 is right: it is designed for rapid, precise and powerful responses, reinforcing strategic autonomy. Statement 3 is right: it aims to cover strategic and civilian sites, including public places, with a nationwide security shield by 2035. So options (b), (c) and (d) fail.
Notice the name: it comes from Lord Krishna's discus, which both protects and strikes. The plan builds on systems like S-400, Akash and the indigenous air defence used in Operation Sindoor (May 2025). It is often compared to Israel's Iron Dome.
Answer as per the official UPSC answer key.
A bond whose proceeds are used only to finance or refinance a combination of both environmental and social projects is called :
Answer (c) & explanation
This is a sustainability bond (c). Under the ICMA principles followed worldwide, a bond that funds a mix of environmental and social projects is a sustainability bond. Option (a) is wrong: a green bond funds only environmental projects, like solar power. Option (b) is wrong: a social bond funds only social projects, like affordable housing. Option (d) is wrong: a sovereign bond is any bond issued by a national government, whatever its use.
Notice India's practice: India has issued Sovereign Green Bonds since January 2023, with the money going to projects like metro rail and renewable energy. A sustainability-linked bond is different: its money can go anywhere, but its interest rate depends on meeting ESG targets.
"Green Bond" is the most familiar term. The words "both environmental and social" point to the combined label.
Answer as per the official UPSC answer key.
The speed of a train T is 100 km per hour and the speed of a person P is 4 km per hour. T crosses P in 15 seconds, if P travels along the direction of motion of T. If P travels along the opposite direction of T, then in how much time does T cross P, in seconds, approximately?
Answer (c) & explanation
The train crosses him in about 13.85 seconds (c). Step 1: same direction: relative speed = 100 − 4 = 96 km/h. The train takes 15 seconds to pass him. Step 2: opposite direction: relative speed = 100 + 4 = 104 km/h. The train's length stays the same, so time falls in proportion. Step 3: time = 15 × 96 ÷ 104 = 1440 ÷ 104 ≈ 13.85 seconds. Options (a), (b) and (d) are close numbers from rounding or arithmetic slips.
Tip: when the distance (train length) is the same, time is inversely proportional to relative speed. No need to find the length itself.
Answer as per the official UPSC answer key.
Read the passage
Previous waves of customer-service technology, including email and those pesky voice menus, stoked concerns of job losses, only for them to fail to materialise. AI could yet prove different. And if it does, its effects may be salutary. Human agents could be freed up to spend more time on creative and rewarding tasks, like using feedback to make products and services better—and thereby spend less time listening to irate customers!
Which one among the following statements most appropriately reflects the point of view of the given passage?
Answer (c) & explanation
The view is that AI might raise the value of human work by moving people to more fulfilling tasks (c). Step 1: the writer's own view is in the last lines: AI's effects "may be salutary" (good). Step 2: human agents "could be freed up" for "creative and rewarding tasks", like using feedback to improve products. That is (c). Step 3: option (a), no work left for humans, is extreme. Options (b) and (d) only describe the background about earlier technology, not the writer's point of view.
Tip: separate background from the author's view. Words like "may be salutary" usually mark the author's own opinion.
Answer as per the official UPSC answer key.
Which of the following temples has/have a Nagara-style shikhara ?
- 1. Malegitti Shivalaya, Badami
- 2. Huchimalligudi Temple, Aihole
- 3. Dashavatara Temple, Deogarh
- 4. Virupaksha Temple, Pattadakal
Select the answer using the code given below :
Answer (b) & explanation
Huchimalligudi and Deogarh have Nagara-style shikharas (b). Item 3 is right: the Dashavatara temple at Deogarh (Gupta period) had an early northern-style shikhara. Item 2 is right: at Aihole, the Huchimalligudi temple carries a curved Nagara (rekha) tower over its sanctum. Items 1 and 4 are wrong: Malegitti Shivalaya at Badami and the Virupaksha temple at Pattadakal are Dravida temples with stepped vimanas. So options (a), (c) and (d) fail.
Notice why the Chalukya sites matter: Aihole, Badami and Pattadakal were a laboratory where both styles stood side by side. Pattadakal, a UNESCO site, has Nagara temples like Papanatha next to Dravida ones. Vesara later blended the two.
The Chalukyan sites have both styles side by side. Do not mark a temple Dravida only because it stands in Karnataka.
Answer as per the official UPSC answer key.
At the United Nations Ocean Conference (UNOC) held in June, 2025 in France, the Food and Agricultural Organization (FAO) of the United Nations demonstrated its leading voice on marine and ocean issues, especially on sustainable fisheries and aquaculture for resilient livelihood and “Blue Transformation”. Which of the following combinations about the “Four Betters” proposed by FAO for “Blue Transformation” is correct ?
Answer (b) & explanation
The Four Betters are production, nutrition, environment and life (b). The "Four Betters" run through FAO's whole strategy (2022–31): better production, better nutrition, a better environment and a better life, leaving no one behind. Blue Transformation applies them to fisheries and aquaculture. Option (a) is wrong: "better ocean" is not one of them. Options (c) and (d) are wrong: coral reefs, estuaries and mangroves are not among the Four Betters.
Notice the link to SDG 14, "Life Below Water". The UN Ocean Conference in Nice, France (2025) pushed for 30% ocean protection, and the High Seas Treaty (BBNJ) came into force in 2026. India's own schemes include the PM Matsya Sampada Yojana.
"better ocean" fits an ocean conference, but the four Betters are FAO's general formula.
Answer as per the official UPSC answer key.
Match List I with List II and select the answer using the code given below the Lists :
| List I (UN Peacekeeping Operation) | List II (Period of Operation)
| A. UNMIL | 1. 2007 – 2010
| B. MINURCAT | 2. 2002 – 2005
| C. MINUSTAH | 3. 2003 – 2018
| D. UNMISET | 4. 2004 – 2017
Code :
Answer (b) & explanation
The correct match is A-3, B-1, C-4, D-2 (b). UNMIL served in Liberia from 2003 to 2018 (A-3). MINURCAT covered the Central African Republic and Chad from 2007 to 2010 (B-1). MINUSTAH was the UN mission in Haiti from 2004 to 2017 (C-4). UNMISET supported newly independent Timor-Leste from 2002 to 2005 (D-2). Options (a), (c) and (d) mix these up.
Notice India's role: India is among the largest troop contributors to UN peacekeeping, with over 2.9 lakh personnel since 1950. In Liberia, India sent the world's first all-women Formed Police Unit in 2007. India's earliest big mission was in Korea and then the Congo (1960s).
Answer as per the official UPSC answer key.
'X' was addressing a seminar on the meaning of the term 'law' as provided under Article 13, Part III of the Constitution of India. 'X' explained that the meaning of the term 'law' in the Constitution of India was very comprehensive. It included ordinances, orders and even rules and regulations. 'Y' pointed out that the term 'law' in Article 13 also included custom or usage having in the territory of India the force of law, to which 'X' was not convinced.
Based on the above, select the correct conclusion from the options given below :
Answer (d) & explanation
Only Y's view is correct (d). Article 13(3)(a) defines "law" to include any Ordinance, order, bye-law, rule, regulation, notification, and custom or usage having the force of law in India. So Y is right that custom is included. Option (a) is wrong: X rejected custom, so his view as a whole fails. Option (b) is wrong: Y's view matches the text. Option (c) is wrong: X's view is not fully correct.
Notice why it matters: Article 13 makes any law, including a custom, void if it violates Fundamental Rights. This is the root of judicial review in India. Courts have struck down discriminatory customs on this basis. Whether personal laws are "law" under Article 13 is still debated.
option (c) tempts you because X's first half is true. UPSC judges the whole view, and X's refusal on custom makes it wrong.
Answer as per the official UPSC answer key.
Read the passage
India is starting to deploy AI for critical use cases such as weather forecasting, pest detection and control, and crop yield optimisation. However, penetration is limited to a small subset of tech-savvy farmers. In the US and in Europe, generative AI tools have started offering precision farming at scale, integrating large datasets to provide real-time agronomic insights. For at-scale integration and accessibility of AI tools in India, it would be helpful to develop Indian languages-based AI tools for smallholder farmers, partner with AgTechs to create affordable AI solutions, and disseminate AI-based advisory services through government programmes.
Which of the following assumptions is/are valid?
- 1. Agricultural productivity has marched ahead in the West because of the economies of scale facilitated by the adoption of AI tools.
- 2. Affordable AI tools rendered available in local languages can help AI-based solutions reach more and more small farmers.
- 3. Though penetration is as yet low, critical application areas deploying AI tools are already in use in India.
Select the answer using the code given below.
Answer (d) & explanation
Assumptions 2 and 3 are valid (d). Step 1: the passage suggests Indian-language AI tools, affordable solutions with AgTechs, and government advisory services to reach smallholders. This rests on assumption 2: affordable, local-language tools can reach more small farmers. Step 2: it opens by saying India is already using AI for weather forecasting, pest control and crop yields, though only among tech-savvy farmers. That is assumption 3. Step 3: assumption 1 says Western farm productivity rose because of AI and economies of scale. The passage only says AI tools "have started" offering precision farming there. So options (a), (b) and (c) fail.
Tip: reject cause-and-effect claims the passage does not make. "Started offering" is not "caused growth".
Answer as per the official UPSC answer key.
Read the passage
The process by which countries close their labour-productivity gap with the technology leader is based on convergence theory. The convergence model divides economic eras into three phases : the breakaway, the catch-up, and the fine-tuning phase. It also divides economic entities into two categories : the technology leaders and the technology followers. The process begins with the development of a new technology, such as scavenging three million years ago (MYA), hunting—one MYA, farming—12 thousand years ago, and industrial technology—a little more than 200 years ago. During the breakaway phase, the per capita income of the technology leaders (e.g., Western Europe and North America in the industrial era) rises, but is unchanged for the technology followers. In the catch-up phase, the followers adopt the new technology and close their per capita income gap with the technology leaders. In the fine-tuning phase, where participants try to extract the remaining benefits from an increasingly exhausted technology, leaders and followers have similar per capita incomes.
Which of the following conclusions are correct?
- 1. In the breakaway phase, economic progress is slow for the technology followers.
- 2. In the catch-up phase, leaders stagnate and followers, therefore, close the gap between them and the leaders.
- 3. In the fine-tuning phase, technology is exhausted, as it were, and both leaders and followers attempt to extract leftover benefits, leading to more or less similar per capita income levels.
- 4. Industrial technology followed scavenging, which preceded hunting, which itself was followed by farming.
Select the answer using the code given below.
Answer (a) & explanation
Conclusions 3 and 4 are correct (a). Step 1: conclusion 3 restates the fine-tuning phase: participants extract the remaining benefits from an "increasingly exhausted" technology, and leaders and followers have similar incomes. Correct. Step 2: conclusion 4 follows the timeline: scavenging (3 million years ago), hunting (1 million), farming (12,000 years) and industry (200 years). Correct. Step 3: conclusion 1 says followers' progress is "slow" in the breakaway phase; the passage says their income is "unchanged". Conclusion 2 says leaders stagnate in catch-up; the passage only says followers close the gap. So options (b), (c) and (d) fail.
Tip: "unchanged" is not "slow"; "followers catch up" does not mean "leaders stagnate". Match the exact word.
Answer as per the official UPSC answer key.
Consider the following statements regarding the British policy in Awadh immediately after its annexation in 1856 :
- 1. The taluqdars were dispossessed of their estates but allowed to retain their arms and forts.
- 2. A Summary Revenue Settlement was made in 1856 assuming that the taluqdars were outsiders.
- 3. The British believed in taking revenue directly from the peasants by removing the taluqdars.
Which of the statements given above is/are correct ?
Answer (a) & explanation
Statements 2 and 3 are correct (a). Statement 2 is right: the Summary Settlement of 1856 treated taluqdars as middlemen, outsiders with no real claim to the land. Statement 3 is right: the British settled revenue directly with the village holders, removing taluqdars. Statement 1 is wrong: taluqdars were disarmed and their forts pulled down, not allowed to keep them. So options (b), (c) and (d) fail.
Notice the result: many angry taluqdars then led the 1857 revolt in Awadh, where Begum Hazrat Mahal led the fight at Lucknow. Awadh was annexed by Dalhousie in 1856 on the ground of "misgovernment", not the Doctrine of Lapse. After 1857, the British reversed course and restored taluqdars.
Answer as per the official UPSC answer key.
Which of the following statements with regard to the National Quantum Mission (NQM) is/are correct ?
- 1. It aims at developing intermediate-scale quantum computers with 50-1000 physical qubits.
- 2. Its implementation includes setting up of four Thematic Hubs (T-Hubs) in academic and national R&D institutes across India.
Select the answer using the code given below :
Answer (c) & explanation
Both statements are correct (c). Statement 1 is right: the National Quantum Mission (2023, under the DST) aims at quantum computers of 50–1,000 physical qubits within eight years. Statement 2 is right: it has four T-Hubs: computing at IISc Bengaluru, communication at IIT Madras, sensing and metrology at IIT Bombay, and materials and devices at IIT Delhi. So options (a), (b) and (d) fail.
Notice the budget: about ₹6,000 crore from 2023-24 to 2030-31. The mission also aims at secure quantum communication over 2,000 km between cities, and satellite-based quantum links. India joined a handful of nations, like the USA, China and France, with such a dedicated mission.
Answer as per the official UPSC answer key.
Which of the following statements with regard to the Grand Slam Tennis Tournaments is/are correct ?
- 1. The tournaments have a shared governance structure establishing the partnership among the four Grand Slam tournaments.
- 2. They are open for entry to all internationally ranked tennis players above the age of 14.
- 3. There is a limitation on the number of ‘Wild Cards’ a player may receive to compete in a Grand Slam Tournament.
Select the answer using the code given below :
Answer (a) & explanation
Statements 1 and 2 are correct as per UPSC (a). Statement 1 is right: the four majors, the Australian Open, Roland Garros, Wimbledon and the US Open, share governance through the Grand Slam Board, which writes common rules. Statement 2 is right: entry is open to internationally ranked players who meet the age rules. Statement 3 is wrong: each tournament gives its own wild cards, and there is no cap on how many a player can receive. So options (b), (c) and (d) fail.
Notice the surfaces: the Australian and US Opens are played on hard courts, Roland Garros on clay, and Wimbledon on grass. Winning all four in one calendar year is a "Calendar Grand Slam", last done in men's singles by Rod Laver in 1969.
Answer as per the official UPSC answer key.
X, Y and Z jump forward 4', 6' and 5', respectively. At 8 AM, they all land on mark 199'. How many times will they all land on the same mark (need not be at the same moment) between mark 195' and 1000', if all of them cross mark 1000' by 9 AM?
Answer (d) & explanation
They land on a common mark 14 times (d). Step 1: all three are at 199' together. After that, they share a mark every LCM(4, 6, 5) = 60'. So common marks are 199, 259, 319, … Step 2: the largest common mark up to 1000' is 199 + 60k ≤ 1000, so k ≤ 13 (199 + 780 = 979). Step 3: k = 0 to 13 gives 14 marks. The mark before 199 would be 139', which is below 195', so it does not count. Options (a), (b) and (c) miss the starting mark or the end.
Tip: common points repeat at the LCM. Count from the first shared point, and include both ends when they fall inside the range.
199' itself counts. It lies between 195' and 1000'.
Answer as per the official UPSC answer key.