UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
If another global financial crisis happens in the near future, which of the following actions/policies are most likely to give some immunity to India ?
- 1. Not depending on short-term foreign borrowings
- 2. Opening up to more foreign banks
- 3. Maintaining full capital account convertibility
Select the correct answer using the code given below :
Answer (a) & explanation
Only statement 1 is correct (a). In a crisis, short-term foreign loans are the first to leave or not be renewed. This happened in the East Asian crisis of 1997, when countries such as Thailand and Indonesia had borrowed heavily short-term. So avoiding them gives protection (1). Statement 2 is wrong because more foreign banks would tie India more closely to world markets. In a crisis, they may pull money back to their home countries. Statement 3 is wrong because full capital account convertibility would let money flow out freely, spreading a shock faster.
India's partial convertibility and large forex reserves helped it weather the 2008 crisis. Notice the Tarapore Committees (1997, 2006), which set preconditions for full convertibility, such as low inflation and a strong banking system.
Answer as per the official UPSC answer key.
If a particular plant species is placed under Schedule VI of The Wildlife Protection Act, 1972, what is the implication ?
Answer (a) & explanation
A licence is needed to cultivate that plant (a). Schedule VI of the Wild Life (Protection) Act, 1972 listed specified plants, such as the red vanda, blue vanda, ladies' slipper orchid and pitcher plant. They could be grown, but only with a licence from the Chief Wildlife Warden, so that plants taken from the wild could not be passed off as cultivated ones. Option (b) is wrong: cultivation is allowed under licence. Option (c) is wrong: GM crops are regulated by the GEAC. Option (d) is wrong: the schedule protects rare plants, it does not list invasive ones.
Notice the 2022 amendment, which cut the schedules from six to four: specified plants are now in Schedule III, and CITES species in Schedule IV.
Answer as per the official UPSC answer key.
Let XYZ be a three-digit number, where (X + Y + Z) is not a multiple of 3. Then (XYZ + YZX + ZXY) is not divisible by
Answer (b) & explanation
The sum is not divisible by 9 (b). Step 1: in XYZ + YZX + ZXY, each digit appears once in every place (hundreds, tens, units). So the sum = 111X + 111Y + 111Z = 111(X + Y + Z). Step 2: 111 = 3 × 37. So the sum is divisible by 3 (a), by 37 (c) and by (X + Y + Z) (d). Step 3: to be divisible by 9, we need a second factor of 3. That would have to come from X + Y + Z, but the question says it is not a multiple of 3. So the sum is not divisible by 9.
Tip: check with numbers: 124 + 241 + 412 = 777 = 111 × 7. 777 ÷ 9 is not whole.
Answer as per the official UPSC answer key.
A person bought a car and sold it for ₹ 3,00,000. If he incurred a loss of 20%, then how much did he spend to buy the car?
Answer (d) & explanation
He spent ₹ 3,75,000 on the car (d). Step 1: a 20% loss means he got back 80% of what he paid. Step 2: 80% = ₹ 3,00,000, so 1% = 3,00,000 ÷ 80 = ₹ 3,750. Step 3: 100% = ₹ 3,75,000. Check: 20% of 3,75,000 is 75,000, and 3,75,000 − 75,000 = 3,00,000. Option (a), ₹ 3,60,000, wrongly adds 20% of the selling price. Options (b) and (c) fail.
Tip: loss and profit % are always on the cost price. So cost = selling price ÷ (1 − loss%). Adding 20% to the selling price is the classic trap.
(a) adds 20% to 3,00,000. The 20% is of the buying price, not the selling price.
Answer as per the official UPSC answer key.
A car travels from a place X to place Y at an average speed of v km/hr, from Y to X at an average speed of 2v km/hr, again from X to Y at an average speed of 3v km/hr and again from Y to X at an average speed of 4v km/hr. Then the average speed of the car for the entire journey
Answer (b) & explanation
The average speed lies between v and 2v (b). Step 1: each trip covers the same distance d. Average speed = total distance ÷ total time, not the average of the speeds. Step 2: total time = d/v + d/2v + d/3v + d/4v = (d/v)(1 + ½ + ⅓ + ¼) = 25d/12v. Step 3: average speed = 4d ÷ 25d/12v = 48v/25 = 1·92v. That is between v and 2v. Option (c) is the trap from averaging the speeds (2·5v).
Tip: for equal distances, the average speed is the harmonic mean, always less than the simple average. Slow legs take more time, so they pull the average down.
the plain average of v, 2v, 3v, 4v is 2·5v. The car spends more time at low speed.
Answer as per the official UPSC answer key.
The Vital-Vidhvansak, the first monthly journal to have the untouchable people as its target audience was published by
Answer (a) & explanation
Gopal Baba Walangkar published it (a). Walangkar, a Mahar ex-soldier and follower of Jyotiba Phule, started Vital-Vidhvansak ("Destroyer of Brahmanical pollution") in 1888. It was the first monthly journal aimed at untouchable readers. He also petitioned against the ban on Mahars joining the army. Jyotiba Phule (b) founded the Satyashodhak Samaj (1873) and wrote Gulamgiri; the paper Deenbandhu (1877) was linked to his movement. Gandhi (c) started Harijan in 1933. Ambedkar (d) launched Mooknayak in 1920, and later Bahishkrit Bharat (1927).
Notice Ambedkar's other milestones: the Mahad Satyagraha (1927) for water rights, the burning of the Manusmriti (1927), and the Poona Pact (1932).
Answer as per the official UPSC answer key.
In India, under cyber insurance for individuals, which of the following benefits are generally covered, in addition to payment for the loss of funds and other benefits ?
- 1. Cost of restoration of the computer system in case of malware disrupting access to one's computer
- 2. Cost of a new computer if some miscreant wilfully damages it, if proved so
- 3. Cost of hiring a specialized consultant to minimize the loss in case of cyber extortion
- 4. Cost of defence in the Court of Law if any third party files a suit
Select the correct answer using the code given below :
Answer (b) & explanation
Items 1, 3 and 4 are covered (b). Personal cyber insurance in India covers losses from online fraud and attacks, as shaped by IRDAI guidelines. Item 1 is right: it pays to restore data and the computer system after malware blocks access. Item 3 is right: in cyber extortion, such as ransomware, it pays for a specialist consultant to limit the loss. Item 4 is right: it pays legal defence costs if a third party sues, say for a privacy breach. Item 2 is wrong: it does not buy a new computer after deliberate physical damage; that falls under ordinary property insurance.
Notice CERT-In, India's agency for cyber incidents, and the national cybercrime helpline 1930. Other covers include identity theft and phishing losses.
Answer as per the official UPSC answer key.
Consider the following minerals :
- 1. Bentonite
- 2. Chromite
- 3. Kyanite
- 4. Sillimanite
In India, which of the above is/are officially designated as major minerals ?
Answer (d) & explanation
Chromite, kyanite and sillimanite are major minerals (d). Under the Mines and Minerals (Development and Regulation) Act, 1957, the Union regulates major minerals, while States make rules for minor minerals. Item 1 is wrong: bentonite, a clay used in drilling and foundries, was notified as a minor mineral in 2015 along with others such as building stone, sand and limestone used in kilns. Item 2 is right: chromite is a major mineral, mined mostly in Odisha (Sukinda valley). Items 3 and 4 are right: kyanite and sillimanite are major minerals used in refractories that resist high heat.
Notice the 2023 amendment to the MMDR Act, which let the Union auction critical minerals such as lithium.
Answer as per the official UPSC answer key.
A family of two generations consisting of six members P, Q, R, S, T and U has three males and three females. There are two married couples and two unmarried siblings. U is P's daughter and Q is R's mother-in-law. T is an unmarried male and S is a male. Which one of the following is correct?
Answer (b) & explanation
R is S's wife (b). Step 1: Q is R's mother-in-law. So Q is in the older generation, and R married Q's child. Step 2: the two unmarried siblings must be T (unmarried male) and U (P's daughter). So R's spouse is the remaining child, S, a male. The couples are P–Q and S–R. Step 3: males: P, S, T. Females: Q, R, U. So R is S's wife. Option (a) fails because U is unmarried. Option (c) fails because S is married. So (d) fails too.
Tip: in family puzzles, first count generations and couples. Then place unmarried people; the married pairs follow.
Answer as per the official UPSC answer key.
What is the greatest length x such that 3½ m and 8¾ m are integral multiples of x?
Answer (d) & explanation
The greatest length is 1¾ m (d). Step 1: write both in quarter-metres: 3½ m = 14/4 and 8¾ m = 35/4. Step 2: HCF(14, 35) = 7. So x = 7/4 = 1¾ m. Step 3: check: 3½ = 2 × 1¾ and 8¾ = 5 × 1¾. Both are whole multiples. Option (c), 1¼, divides 8¾ (7 times) but not 3½. Options (a) and (b) fail too.
Tip: for the HCF of fractions, put them over a common denominator and take the HCF of the numerators. Or use HCF of numerators ÷ LCM of denominators.
Answer as per the official UPSC answer key.
With reference to the funds under Members of Parliament Local Area Development Scheme (MPLADS), which of the following statements are correct ?
- 1. MPLADS funds must be used to create durable assets like physical infrastructure for health, education, etc.
- 2. A specified portion of each MP’s fund must benefit SC/ST populations.
- 3. MPLADS funds are sanctioned on yearly basis and the unused funds cannot be carried forward to the next year.
- 4. The district authority must inspect at least 10% of all works under implementation every year.
Select the correct answer using the code given below :
Answer (d) & explanation
Statements 1, 2 and 4 are correct (d). Under MPLADS, started in 1993, each MP gets ₹5 crore a year for local works. Statement 1 is right because the money must be used for durable community assets, such as roads, school buildings, health centres and drinking water. Statement 2 is right because at least 15% must go to areas with SC people and 7.5% to areas with ST people. Statement 4 is right because the district authority must inspect at least 10% of works each year. Statement 3 is wrong because MPLADS funds are non-lapsable: unspent money carries forward to the next year.
The scheme was suspended for two years in 2020–22 to fund COVID relief. Notice the 2023 guidelines, which moved funds to an online e-SAKSHI portal for tracking.
Answer as per the official UPSC answer key.
With reference to Visible Light Communication (VLC) technology, which of the following statements are correct ?
- 1. VLC uses electromagnetic spectrum wavelengths 375 to 780 nm.
- 2. VLC is known as long-range optical wireless communication.
- 3. VLC can transmit large amounts of data faster than Bluetooth.
- 4. VLC has no electromagnetic interference.
Select the correct answer using the code given below :
Answer (c) & explanation
Statements 1, 3 and 4 are correct (c). Visible Light Communication (VLC), also called Li-Fi, sends data by switching LED lights on and off very fast, too fast for the eye to notice. Statement 1 is right because it uses visible light, about 375–780 nm. Statement 3 is right because it can carry large amounts of data faster than Bluetooth, even faster than Wi-Fi in labs. Statement 4 is right because light causes no radio-frequency interference, so it suits hospitals, aircraft and mines. Statement 2 is wrong because light cannot pass through walls, which makes VLC a short-range technology.
Harald Haas coined the term "Li-Fi" in 2011. Notice that the IEEE 802.11bb standard (2023) brought Li-Fi into the Wi-Fi family.
Answer as per the official UPSC answer key.
With reference to the cultural history of India, consider the following pairs :
- 1. Parivrajaka — Renunciant and Wanderer
- 2. Shramana — Priest with a high status
- 3. Upasaka — Lay follower of Buddhism
Which of the pairs given above are correctly matched ?
Answer (b) & explanation
Pairs 1 and 3 are correct (b). Pair 1 is right: a parivrajaka was a wandering renouncer who left home to seek truth, common in the age of the Buddha and Mahavira. Pair 2 is wrong: shramanas were ascetics outside the Brahmanical order, such as Buddhist, Jain and Ajivika monks, and they rejected priestly rank and Vedic ritual. A priest of high status would be a Brahmin or purohita. Pair 3 is right: an upasaka (male) or upasika (female) was a lay Buddhist who took the three refuges and the five precepts but did not become a monk.
Notice the Buddhist community: the sangha of bhikkhus and bhikkhunis, plus lay followers. Notice too Makkhali Gosala, who led the Ajivikas.
Answer as per the official UPSC answer key.
With reference to the religious history of India, consider the following statements :
- 1. Sthaviravadins belong to Mahayana Buddhism.
- 2. Lokottaravadin sect was an offshoot of Mahasanghika sect of Buddhism.
- 3. The deification of Buddha by Mahasanghikas fostered the Mahayana Buddhism.
Which of the statements given above is/are correct ?
Answer (b) & explanation
Statements 2 and 3 are correct (b). Statement 1 is wrong because the Sthaviravadins ("elders") are the root of the Hinayana schools, such as Theravada, not Mahayana. At the Second Buddhist Council (Vaishali, about 383 BCE), the Sangha split into the Sthaviravadins and the Mahasanghikas over monastic rules. Statement 2 is right because the Lokottaravadins were an offshoot of the Mahasanghikas. They saw the Buddha as lokottara, above the world. Statement 3 is right because this raising of the Buddha into a divine figure led towards Mahayana.
Notice the four councils: Rajagriha (Ajatashatru), Vaishali (Kalashoka), Pataliputra (Ashoka) and Kashmir (Kanishka). Pali was declared a classical language in 2024.
Answer as per the official UPSC answer key.
Two Statements S1 and S2 are given below with regard to two numbers followed by a Question :
S1 : Their product is 21.
S2 : Their sum is 10.
Question : What are the two numbers?
Which one of the following is correct in respect of the above Statements and the Question?
Answer (c) & explanation
S1 and S2 together are sufficient, but neither alone (c). Step 1: S1 alone: two numbers with product 21 could be 1 and 21 or 3 and 7 (or even fractions). Not enough. Step 2: S2 alone: many pairs add to 10: 1 and 9, 2 and 8, and so on. Not enough. Step 3: together: among pairs with product 21, only 3 and 7 add to 10. Algebra agrees: x + y = 10 and xy = 21 give x² − 10x + 21 = 0, so x = 3 or 7. The numbers are fixed. Options (a), (b) and (d) fail.
Tip: a sum and a product together fix two numbers, since they make a quadratic with one pair of roots.
Answer as per the official UPSC answer key.
Read the passage
India has tremendous potential for solar energy. We all realize that we have to stop burning fossil fuels to meet our energy needs. But certain renewable resources are still going through their cost curves and learning curves to get the required amount of output. The Indian Government has strongly committed to its targets of reducing emissions by 33 per cent by 2030, and towards this it has initiated a strong push towards a gas-based economy and has also invested heavily in renewable energy. However, business houses are wary of investing too heavily in renewable energy at a time when the technology is not yet ready.
Which one of the following is the most logical and rational inference that can be made from the above passage?
Answer (c) & explanation
The inference is that rushing renewables to market too soon may be costly (c). Step 1: the passage says renewables are "still going through their cost curves", meaning their prices are still falling. Business is wary while "the technology is not yet ready". So pushing them early is costly. That is (c). Step 2: option (a) predicts India will miss its 33% target. The passage does not predict this. Step 3: option (b), import gas instead of renewables, and option (d), more gas exploration, are not suggested.
Tip: a cost curve shows prices falling as technology matures. Solar power costs in India fell sharply over the last decade for this reason.
Answer as per the official UPSC answer key.
The Preamble to the Constitution of India is
Answer (d) & explanation
Option (d) is correct. In Kesavananda Bharati (1973), the Supreme Court held that the Preamble is part of the Constitution, reversing the opinion in Berubari Union (1960) that it was not. Option (b) is therefore wrong. The Preamble is not enforceable on its own in a court; a person cannot sue only because a Preamble ideal is not met. But it guides how the other provisions are read and explained, especially where the text is unclear. That is why option (c) is wrong, as it does not have the same legal effect as other parts. Option (a) goes too far in saying it has no legal effect at all.
The 42nd Amendment (1976) added "socialist", "secular" and "integrity". Notice that the Court upheld these words in November 2024.
(a) and (d) differ by one word: "independently". The Preamble has effect through the other parts.
Answer as per the official UPSC answer key.
If you withdraw ₹1,00,000 in cash from your Demand Deposit Account at your bank, the immediate effect on aggregate money supply in the economy will be
Answer (d) & explanation
The money supply stays unchanged (d). Money supply, both M1 (narrow money) and M3 (broad money), is mainly currency with the public plus deposits with banks. When you withdraw ₹1 lakh in cash from a demand deposit, such as a savings or current account, your deposit falls by ₹1 lakh, and currency with the public rises by the same ₹1 lakh. The total does not change; only its form does. So options (a), (b) and (c) are wrong. Over time, lower bank reserves can reduce lending, but the question asks only about the immediate effect.
Notice the other measures: M0 is reserve money, and M3 includes time deposits. The RBI uses M3 as its main measure of money supply.
Answer as per the official UPSC answer key.
With reference to the period of Gupta dynasty in ancient India, the towns Ghantasala, Kadura and Chaul were well known as
Answer (a) & explanation
They were ports handling foreign trade (a). Ghantasala and Kadura (Koduru) lay on the Andhra coast near the Krishna delta, and Chaul on the Konkan coast near Mumbai. In the Gupta period and earlier, these ports traded with South-east Asia, the Roman world and the Arabs, exporting textiles, spices and gems. Option (b) is wrong: they were not royal capitals. Option (c) is wrong: they were not known for stone art. Option (d) is a trap: Ghantasala had a Buddhist stupa, but here it is grouped as a port.
Notice other ports of the time: Tamralipti in Bengal and Bharukachchha (Broach). Notice too the Periplus of the Erythraean Sea, which lists ports of the early centuries AD.
Answer as per the official UPSC answer key.
Let p, q, r and s be natural numbers such that p – 2016 = q + 2017 = r – 2018 = s + 2019. Which one of the following is the largest natural number?
Answer (c) & explanation
r is the largest (c). Step 1: call the common value k. Then p − 2016 = k gives p = k + 2016. q + 2017 = k gives q = k − 2017. Step 2: r − 2018 = k gives r = k + 2018. s + 2019 = k gives s = k − 2019. Step 3: compare: r has the biggest number added, so r is the largest. p is second. q and s are smaller. Options (a), (b) and (d) fail.
Tip: setting a chain of equal expressions to one letter, k, makes comparison easy. Watch the signs: "p minus 2016" means p is bigger than k, while "q plus 2017" means q is smaller than k.
Answer as per the official UPSC answer key.