UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
Three variables x, y and z take values 2, 3, 4 or 5 such that their values are always distinct. If M and N denote the largest possible value and the smallest possible value, respectively, for the expression {(x × y) + z}; then M – N is
Answer (c) & explanation
M − N is 13 (c). Step 1: to make (x × y) + z largest, multiply the two biggest numbers and add the next one: M = 5 × 4 + 3 = 23. (Check: 5 × 3 + 4 = 19 and 4 × 3 + 5 = 17 are smaller.) Step 2: to make it smallest, multiply the two smallest and add the next smallest: N = 2 × 3 + 4 = 10. (Check: 2 × 4 + 3 = 11 is bigger.) Step 3: M − N = 23 − 10 = 13. Options (a), (b) and (d) come from other pairings.
Tip: multiplication has a bigger effect than addition, so give the product the biggest (or smallest) numbers. Quickly check one or two other pairings to be safe.
Answer as per the official UPSC answer key.
Read the passage
Was it the sun-dappled ambience, the strawberries and cream, the frustration of Flavio Cobolli’s unforced errors against Serbian Novak Djokovic on Centre Court or simply the crushing weight of being a 64-year-old man in the third act of a very public life? Whatever the reason, Hugh Grant, the actor, deserves empathy. There he was, in the Royal Box at Wimbledon, flanked by Britain’s well-dressed and well-rested spectators, watching the men’s singles quarterfinals, when the actor did something quietly radical : head at a tilt, eyes closed, utterly unbothered, he took a nap. So praise be to Grant for serving up an unexpected ace. In that small, delicious moment, he didn’t merely catch forty winks, he made an elegant case for surrender. Not to laziness, but to limits. To the body’s quiet wisdom over society’s relentless performance metrics. Wimbledon had its tennis. The perpetually sleep-deprived discovered a leading man, not of action, but of rest.
Which of the following statements is/are correct?
- 1. Radical action can also be attributed to mild surrender where one acts against societal expectations.
- 2. Submitting to one’s limitations, given the effect of age and other factors, ought not to be conflated with laziness.
- 3. ‘Leading man’ usually refers to one who plays the lead role in a movie; in this instance the implication is that Hugh Grant is performing the role of not an action hero, but that of a resting one!
Select the answer using the code given below.
Answer (c) & explanation
All three statements are correct (c). Step 1: statement 1: the writer calls Hugh Grant's nap "quietly radical" and "an elegant case for surrender". Napping in the formal Royal Box goes against social expectation, so mild surrender becomes radical action. Correct. Step 2: statement 2 matches "Not to laziness, but to limits": giving in to age and tiredness is not laziness. Correct. Step 3: statement 3 explains the pun in the last line: "a leading man, not of action, but of rest". A leading man is a film's lead actor; here Grant leads in resting. Correct. So options (a), (b) and (d) fail.
Tip: in light, witty passages, look for wordplay. The nap happened at Wimbledon in July 2025, during the Djokovic–Cobolli quarterfinal.
Answer as per the official UPSC answer key.
Which of the following pairs of the king and his dynasty in early historical Tamilakam is/are not correctly matched ?
- 1. Senguttuvan : Chera
- 2. Udiyanjeral : Chola
- 3. Nedunjeliyan : Pandya
Select the answer using the code given below :
Answer (b) & explanation
Only pair 2 is not correctly matched (b). The Sangam poems name three crowned houses: Chera, Chola and Pandya. Pair 1 is correct: Senguttuvan, hero of the Kannagi cult, was a Chera. Pair 3 is correct: Nedunjeliyan, the victor of Talaiyalanganam, was a Pandya. Pair 2 is wrong: Udiyanjeral was a Chera, not a Chola; "-jeral" is a Chera ending. So the answer is pair 2 only.
Notice the trap: the question asks which is not correctly matched. Senguttuvan's story is told in Silappadikaram. Karikala is the most famous early Chola, linked to the Kallanai dam. The Pathitrupathu sings of Chera kings, and Madurai was the Pandya seat.
This one asks for "not correctly matched". Mark the wrong pair, not the right ones.
Answer as per the official UPSC answer key.
Which of the following statements with regard to drone swarms is/are correct ?
- 1. They use Terahertz band of frequency to communicate with the command centre.
- 2. Individual drones in the swarm can communicate with other drones in the swarm.
- 3. GPS Spoofing is a commonly used technique to counter drone swarm attack.
Select the answer using the code given below :
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 2 is right: in a swarm, the drones talk to each other and share tasks, so the group keeps working even if some are lost. Statement 3 is right: defenders often jam or spoof GPS to send them off course. Statement 1 is wrong: swarms usually use ordinary radio bands; terahertz links are still experimental and short-range. So options (a), (c) and (d) fail.
Notice other counters: laser weapons, like DRDO's directed-energy systems, anti-drone guns and net systems. India showed a 75-drone swarm at the 2021 Army Day parade. Drone wars in Ukraine and during Operation Sindoor (2025) showed how cheap drones can overwhelm costly defences.
Answer as per the official UPSC answer key.
The Bureau of Indian Standard (BIS) recently introduced a national standard to test and assess bomb disposal system. Which of the following statements with regard to this system is/are correct ?
- 1. The new standard is known as IS 19445 : 2025.
- 2. It will improve interoperability of equipment across agencies.
- 3. It was developed by TBRL, DRDO in collaboration with the Central Scientific Research Institute, Russia.
Select the answer using the code given below :
Answer (c) & explanation
Statements 1 and 2 are correct (c). Statement 1 is right: the Bureau of Indian Standards issued IS 19445 : 2025, India's first national standard to test and assess bomb disposal systems. Statement 2 is right: one common test standard improves interoperability of equipment across police, armed forces and security agencies. Statement 3 is wrong: it was developed with DRDO's Terminal Ballistics Research Laboratory (TBRL), Chandigarh, with no Russian partner. So options (a), (b) and (d) fail.
Notice the purpose: earlier, agencies tested equipment like bomb suits, containment vessels and robots against foreign standards. A domestic standard helps indigenous makers under Atmanirbhar Bharat. BIS works under the Ministry of Consumer Affairs and gained statutory status in 1986.
Answer as per the official UPSC answer key.
The weight of X, in kg, is denoted by X. The weights of A, B, C, D, P, Q, R and S are measured. Given :
A + B + C + D = 17
A + C = 6
P + Q + S + D = 15
P + Q + R + B = 17
P = R and Q = S
Which one of the following statements is correct?
Answer (b) & explanation
1. From the first two equations: B + D = 11.
2. Put R = P and S = Q, then add the last two equations: 3P + 3Q + B + D = 32, so 3(P + Q) = 21 and P + Q = 7.
3. 7 > 6 = A + C, so (b) is true. (a) fails because 11 > 7. P and Q separately cannot be fixed, so (c) and (d) cannot be claimed.
Answer as per the official UPSC answer key.
Read the passage
The Juvenile Justice (Care and Protection of Children) Act, or the JJ Act, 2015 allows for the possibility for trying adolescents above 16 as adults if they are accused of committing a heinous offence. A heinous offence is one with a minimum punishment of seven years. Offences such as culpable homicide and causing death by negligence, which are common in drunken driving cases, are not heinous offences because they do not have a prescribed minimum punishment. The JJ Act, amended in 2021, now categorises an offence that has no minimum sentence, but has a maximum sentence of seven years or more as a serious offence which nonetheless, in the opinion of activists, does not merit the transfer of a case to the adult criminal justice system.
Which of the following statements is/are correct?
- 1. If an offence has no minimum prescribed punishment, it cannot be considered heinous as per the JJ Act, 2015.
- 2. As per the JJ Act, 2021, an offence for which there is a provision for a maximum sentence of seven years or more, but no minimum sentence, is to be considered a serious offence.
Select the answer using the code given below.
Answer (c) & explanation
Both statements are correct (c). Step 1: statement 1: the passage says a heinous offence has a minimum punishment of seven years, and gives culpable homicide as an example that is not heinous "because they do not have a prescribed minimum punishment". So an offence with no minimum cannot be heinous: correct. Step 2: statement 2 repeats the 2021 amendment: no minimum sentence plus a maximum of seven years or more = serious offence. Correct. Step 3: so options (a), (b) and (d) fail.
Tip: when a passage gives a definition plus an example, use both to test statements. The example (culpable homicide) confirms the rule in statement 1.
Answer as per the official UPSC answer key.
| List-I (Relationship category) | List-II (Communication type) |
|---|---|
| A. Between cricket captain and team members | 1. Informal and firm |
| B. Between judge and lawyers in court | 2. Informal and open-ended |
| C. Between Vice Chancellor and Deputy Registrar | 3. Formal and open-ended |
| D. Between peers and coworkers | 4. Formal and firm |
Match List-I with List-II and select the answer using the code given below the Lists :
Answer (b) & explanation
The match is A-1, B-4, C-3, D-2 (b). Step 1: a court is the most formal and binding setting, so judge and lawyers = formal and firm (B-4). Peers and coworkers talk freely and loosely = informal and open-ended (D-2). Step 2: a cricket captain is friendly with players, but his decision is final = informal and firm (A-1). Step 3: a Vice Chancellor and Deputy Registrar work through official channels but discuss matters = formal and open-ended (C-3). Options (a), (c) and (d) mismatch these.
Tip: in matching questions, fix the clearest pairs first (here court and peers). The rest often fall into place.
Answer as per the official UPSC answer key.
Which of the following with reference to Indian States is/are not correct ?
- 1. Uttar Pradesh shares its boundary with the highest number of other Indian States.
- 2. Rajasthan shares the longest international border among all Indian States.
- 3. Sikkim is the only State that shares its boundary with just one other Indian State.
Select the answer using the code given below :
Answer (c) & explanation
Statements 2 and 3 are not correct (c). Statement 1 is correct: Uttar Pradesh touches eight States, plus Delhi, the most of any State. Statement 2 is wrong: the longest international border belongs to West Bengal, with Bangladesh, not Rajasthan. Statement 3 is wrong: Sikkim touches only West Bengal, but Meghalaya also touches only one State, Assam, so the word "only" fails. So options (a), (b) and (d) fail.
Notice the trap: the question asks which are not correct. UP's neighbours are Uttarakhand, Himachal, Haryana, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand and Bihar. Rajasthan has the longest border with Pakistan, about 1,070 km. Words like "only", "all" and "never" often hide the error.
The question asks for statements that are not correct. Statement 3 is half right; the word "only" breaks it.
Answer as per the official UPSC answer key.
Consider the following statements about the Committee on the Welfare of Scheduled Castes and Scheduled Tribes of the Parliament of India :
- 1. Although members of this Committee are elected from both Houses of Parliament, the Chairperson of this Committee is appointed by the Chairman of the Rajya Sabha.
- 2. Twenty members are elected by the Rajya Sabha and ten members by the Lok Sabha.
- 3. No Minister, except for the Union Minister of Social Justice and Empowerment, is eligible to be a member of this Committee.
- 4. Members are elected for a fixed term of two years from the date they enter their office.
Which one of the following conclusions based on the above statements is correct ?
Answer (d) & explanation
No statement is correct (d). The Committee on the Welfare of SCs and STs has 30 members. Statement 1 is wrong: the Speaker appoints its Chairperson from among the Lok Sabha members. Statement 2 is wrong: 20 members come from the Lok Sabha and 10 from the Rajya Sabha, the reverse of the statement. Statement 3 is wrong: no Minister at all can be a member. Statement 4 is wrong: the term is one year, not two. So options (a), (b) and (c) fail.
Notice the pattern: like the Estimates and Public Accounts committees, it is a financial-style committee where Ministers are barred. Its job is to examine the work of the National Commissions for SCs and STs and the implementation of safeguards.
four confident details, all slightly off. When every line has a number or an office, check each one.
Answer as per the official UPSC answer key.
Which of the following statements about Real-World Assets (RWA) Tokenization are correct ?
- 1. Tokenization is the process of turning real world assets into digital tokens using blockchain technology.
- 2. Tokenization of real world assets offers 24x7 access, promoting financial inclusion.
- 3. Tokenization of real world assets will allow the access to high growth investment opportunities for individuals in India.
Select the answer using the code given below :
Answer (a) & explanation
All three statements are correct (a). Statement 1 is right: tokenization turns a real asset, like a building, bond or gold, into digital tokens recorded on a blockchain. Statement 2 is right: tokens can be traded 24x7, which widens financial inclusion. Statement 3 is right: small, fractional tokens let ordinary individuals get into high-growth investments that once needed crores. So options (b), (c) and (d) fail.
Notice the risks: unclear regulation, cyber threats and weak investor protection. In India, related steps include Fractional Ownership Platforms and REITs and InvITs, which already let small investors own slices of real estate and infrastructure. The RBI is also testing tokenized deposits and government securities in sandbox pilots.
Answer as per the official UPSC answer key.
If 10m × 1000 × n = 7525 × 2532 × 3275, where n is not divisible by 10, then the value of m is
Answer (b) & explanation
m is 111 (b). Step 1: each 10 needs one 2 and one 5. Count the 5s: 75²⁵ = (3 × 5²)²⁵ = 3²⁵ × 5⁵⁰, and 25³² = 5⁶⁴. Total 5s = 50 + 64 = 114. Step 2: count the 2s: 32⁷⁵ = (2⁵)⁷⁵ = 2³⁷⁵. Far more than 114. Step 3: so the right side has exactly 114 factors of 10 (n has no more, since n is not divisible by 10). The left side has 10ᵐ × 1000 = 10^(m + 3). So m + 3 = 114 and m = 111. Options (a), (c) and (d) fail.
Tip: the number of 10s equals the smaller count of 2s and 5s. Do not forget the extra 10s hidden in 1000.
remember the 1000 on the left: it already holds 103.
Answer as per the official UPSC answer key.
Seven cubes are identical in shape. Out of these, the weight of each of the six cubes is equal and the weight of the remaining cube is less than the weight of any other cube. A balance is used to identify the lightest cube. What is the minimum number of attempts required to distinguish the odd cube with certainty?
Answer (a) & explanation
Two weighings are enough (a). Step 1: put 3 cubes against 3, keeping one aside. If they balance, the cube kept aside is the light one: done in one weighing. Step 2: if one side is lighter, the odd cube is among those three. Weigh 1 against 1 of them. Step 3: the lighter pan holds the odd cube; if they balance, it is the third cube. So 2 weighings always work. One weighing (d) cannot cover all cases. Options (b) and (c) use more than needed.
Tip: each weighing has three outcomes (left, right, balance), so split into three groups. With n weighings you can find a light coin among up to 3ⁿ coins.
one weighing can only split the cubes into three groups (left, right, aside), so 7 cubes need at least two.
Answer as per the official UPSC answer key.
Consider the following statements :
- I. Pali texts contain the first definite references to coins, e.g., kahapana, nikkha, kamsa, and kakanika.
- II. The literary evidence from Pali texts is corroborated by archaeological evidence of punch-marked coins from many sites, most of them made of silver.
The above statements have been associated with which of the following ?
- 1. Emergence of urban life
- 2. Transition to money economy
Select the answer using the code given below :
Answer (c) & explanation
Both are linked to urban life and a money economy (c). Statement I: the Pali texts name coins such as kahapana, nikkha, kamsa and kakanika. Statement II: silver punch-marked coins turn up at many sites. Item 1 is right: coins and the cities of the second urbanisation (6th century BCE onward) grew up together. Item 2 is right: both point to trade paid for in money, not barter. So options (a), (b) and (d) fail.
Notice the context: the rise of the mahajanapadas, cities like Rajagriha, Shravasti and Kaushambi, and the Northern Black Polished Ware pottery. Punch-marked coins had symbols stamped on them, with no king's name or writing. Later the Indo-Greeks issued coins with rulers' portraits.
Answer as per the official UPSC answer key.
Which one of the following statements with regard to the Moidams, built by the Tai-Ahom kingdom and inscribed as a World Heritage Site by UNESCO, is/are correct ?
- 1. They acted as army fortresses.
- 2. They were recreation centres of the Royals and Nobles.
- 3. They were burial grounds of the Royals and Nobles.
- 4. They were battle drill centres of the Royals and Nobles.
Select the answer using the code given below :
Answer (c) & explanation
Only statement 3 is correct (c). The Moidams of Charaideo in Assam are earthen burial mounds of Ahom kings, queens and nobles, raised over vaulted chambers from the 13th to the 19th century. Statement 3 is right. Statements 1, 2 and 4 are wrong: they were never army forts, recreation centres or battle drill grounds. So options (a), (b) and (d) fail.
Notice their status: in 2024 they became the North-East's first cultural World Heritage Site, and India's 43rd. They are often called the "pyramids of Assam". The Ahoms ruled Assam for about 600 years, and their general Lachit Borphukan defeated the Mughals at Saraighat (1671). Charaideo was their first capital.
Answer as per the official UPSC answer key.
Consider the following UN organisations/agencies :
- 1. World Food Programme
- 2. United Nations Children’s Fund
- 3. United Nations High Commissioner for Refugees
- 4. International Labour Organisation
How many of the above has/have been awarded the Nobel Prize twice ?
Answer (a) & explanation
Only one of these won the Nobel Peace Prize twice (a). Item 3 is right: the UNHCR won in 1954 and 1981. Item 1 is wrong: the World Food Programme won once, in 2020. Item 2 is wrong: UNICEF won once, in 1965. Item 4 is wrong: the ILO won once, in 1969, its 50th year. So options (b), (c) and (d) fail.
Notice the record holder: the International Committee of the Red Cross has won three times (1917, 1944, 1963), the most of any organisation. The UN and Kofi Annan shared the prize in 2001, and UN Peacekeeping Forces won in 1988. The IAEA won in 2005. Indian-born Kailash Satyarthi shared the 2014 prize.
Answer as per the official UPSC answer key.
What does an empty seat represent in early Buddhist iconography ?
Answer (a) & explanation
An empty seat represents the Buddha's meditation (a). Early Buddhist art at Bharhut and Sanchi does not show the Buddha in human form. Symbols stand in for him: an empty seat, often under the Bodhi tree, for his meditation and enlightenment. Option (b) is wrong: a wheel stands for the First Sermon at Sarnath. Option (c) is wrong: a stupa stands for the Mahaparinibbana, his death. Option (d) is wrong: a horse stands for the Great Departure (Mahabhinishkramana).
Notice the later change: the Gandhara and Mathura schools, under the Kushanas, first showed the Buddha as a human. Other symbols: a lotus or elephant for his birth, and footprints for his presence. This early stage is called aniconic.
The key follows UPSC's provisional key. The usual symbol table pairs each event with a different sign, so learn all four together.
Answer as per the official UPSC answer key.
Suppose x, y and z are variables taking positive real numbers as their possible values. It is given that y is directly proportional to x2 and x is inversely proportional to z. For z = 7/25, the values of x and y are 5 and 50, respectively. If y = 98, what is z equal to?
Answer (b) & explanation
z equals 1/5 (b). Step 1: y is directly proportional to x², so y = k × x². With x = 5 and y = 50: 50 = k × 25, so k = 2. Step 2: y = 98 means 2x² = 98, so x² = 49 and x = 7. Step 3: x is inversely proportional to z, so x × z stays the same. At the start: 5 × 7/25 = 7/5. Now 7 × z = 7/5, so z = 1/5. Options (a), (c) and (d) fail.
Tip: "directly proportional" means the ratio stays fixed; "inversely proportional" means the product stays fixed. Find the constant first, then use it.
Answer as per the official UPSC answer key.
Read the passage
Was it the sun-dappled ambience, the strawberries and cream, the frustration of Flavio Cobolli’s unforced errors against Serbian Novak Djokovic on Centre Court or simply the crushing weight of being a 64-year-old man in the third act of a very public life? Whatever the reason, Hugh Grant, the actor, deserves empathy. There he was, in the Royal Box at Wimbledon, flanked by Britain’s well-dressed and well-rested spectators, watching the men’s singles quarterfinals, when the actor did something quietly radical : head at a tilt, eyes closed, utterly unbothered, he took a nap. So praise be to Grant for serving up an unexpected ace. In that small, delicious moment, he didn’t merely catch forty winks, he made an elegant case for surrender. Not to laziness, but to limits. To the body’s quiet wisdom over society’s relentless performance metrics. Wimbledon had its tennis. The perpetually sleep-deprived discovered a leading man, not of action, but of rest.
Which of the following statements is/are correct?
- 1. Hugh Grant was watching, from the Royal Box, the men’s semifinal match on Centre Court between Flavio Cobolli and Novak Djokovic.
- 2. The phrase ‘unexpected ace’ in the context uses a term from the game of tennis to highlight Hugh Grant’s somewhat uncharacteristic act of catching ‘forty winks’; an act that is viewed with opprobrium.
- 3. Grant subjects the demands of society to the wisdom of his body.
Select the answer using the code given below.
Answer (b) & explanation
Only statement 3 is correct (b). Step 1: statement 3 matches "the body's quiet wisdom over society's relentless performance metrics". Grant let his body's need win over social demands. Correct. Step 2: statement 1 says it was the semifinal. The passage says "men's singles quarterfinals". Wrong. Step 3: statement 2 rightly explains "ace" as a tennis term, but adds that the nap is viewed with "opprobrium" (disgrace). The writer praises it: "praise be to Grant". So 2 is wrong. Options (a), (c) and (d) fail.
Tip: a statement that is half right is still wrong. Check every part, especially the tone words like "opprobrium". The match was played on 9 July 2025.
Answer as per the official UPSC answer key.
Which of the following factors contributed to the formation of the Forward Bloc by Subhas Chandra Bose in 1939 ?
- 1. Bose failed to win the confidence of Mahatma Gandhi.
- 2. The Congress Left was disunited and failed to support Bose.
- 3. The Communists did not support Bose in his endeavours.
- 4. The supporters of M.N. Roy and socialist leaders like Jayaprakash Narayan preferred Congress unity to supporting Bose.
Select the answer using the code given below :
Answer (b) & explanation
Factors 1, 2 and 4 contributed (b). Bose beat Gandhi's choice, Pattabhi Sitaramayya, at Tripuri (1939). Factor 1 is right: Gandhi then held back, Bose could not form a Working Committee, and he resigned. Factor 2 is right: the Congress Left was split and did not back him. Factor 4 is right: CSP leaders like Jayaprakash Narayan and M.N. Roy's supporters put Congress unity first. Factor 3 is not in UPSC's key. So in May 1939 Bose founded the Forward Bloc inside Congress.
Notice what came next: Rajendra Prasad became Congress president. Bose escaped India in 1941, went to Germany and Japan, and led the Indian National Army (Azad Hind Fauj) from 1943.
Answer as per the official UPSC answer key.