UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
(Same information as the question above.)
What is the profession of D ?
Answer (b) & explanation
D is the stenographer (b). Step 1: from the earlier working, B is the judge. The only jobs left for B and D were judge and stenographer. Step 2: so D is the stenographer. Step 3: check: A, the engineer, is married to the lady stenographer, and D is a lady, the grandmother of F. This fits. Option (a) is wrong: B is the judge. Option (c) is wrong: E is the doctor. Option (d) is wrong: the answer can be fixed.
Tip: in a set of linked questions, solve the puzzle once in a small table of names and jobs. Each question then takes seconds.
Answer as per the official UPSC answer key.
In the context of Indian economy, which of the following is/are the purpose/purposes of 'Statutory Reserve Requirements'?
- 1. To enable the Central Bank to control the amount of advances the banks can create
- 2. To make the people's deposits with banks safe and liquid
- 3. To prevent the commercial banks from making excessive profits
- 4. To force the banks to have sufficient vault cash to meet their day-to-day requirements
Select the correct answer using the code given below.
Answer (a) & explanation
Statutory reserve requirements are the CRR and SLR. By raising or lowering them, the RBI changes how much money banks can lend, so their key purpose is to control credit creation (1 correct). Deposit safety and liquidity (2) are only a side effect, not the stated purpose in UPSC's key. Curbing bank profits (3) is no aim at all, and keeping vault cash for daily needs (4) is the bank's own business.
The CRR is held as cash with the RBI; the SLR is kept in liquid assets such as government securities. Notice how these are quantitative tools, unlike qualitative tools such as moral suasion.
statement 2 sounds right because SLR assets are safe and liquid. The question asks for the purpose, which is credit control.
Answer as per the official UPSC answer key.
Which of the following statements is/are correct regarding vegetative propagation of plants?
- 1. Vegetative propagation produces clonal population.
- 2. Vegetative propagation helps in eliminating the virus.
- 3. Vegetative propagation can be practiced most of the year.
Select the correct answer using the code given below.
Answer (c) & explanation
Vegetative propagation, by cuttings, grafting, layering or tubers, gives genetically identical clones (1 correct) and can be done for most of the year (3 correct). Statement 2 is wrong: it passes on viruses present in the parent tissue rather than eliminating them. So the answer is (c).
To get virus-free plants, growers use meristem culture, since the growing tip of a plant is often free of virus. Banana, potato and sugarcane are often propagated this way. Notice how clonal crops are uniform but share the same weaknesses, so one disease can wipe out whole fields.
Answer as per the official UPSC answer key.
With reference to Union Budget, which of the following is/are covered under Non-Plan Expenditure?
- 1. Defence expenditure
- 2. Interest payments
- 3. Salaries and pensions
- 4. Subsidies
Select the correct answer using the code given below.
Answer (c) & explanation
All four were Non-Plan expenditure (c). Until 2016-17 the Budget split spending into Plan (new schemes and projects under the Five-Year Plan) and Non-Plan (running costs). Defence, interest payments, salaries and pensions, and subsidies all fell under Non-Plan. Options leaving out any of them are incomplete.
From 2017-18 the Plan/Non-Plan split was dropped, following the end of Five-Year Plans, and the Budget now uses revenue and capital expenditure. The same year the Railway Budget was merged into the Union Budget. Notice how fiscal terms change with reforms, so read such questions in their year.
this split no longer exists. Learn it for history and know today's revenue/capital split.
Answer as per the official UPSC answer key.
Read the passage
The Himalayan ecosystem is highly vulnerable to damage, both due to geological reasons and on account of the stress caused by increased pressure of population, exploitation of natural resources and other related challenges. These aspects may be exacerbated due to the impact of climate change. It is possible that climate change may adversely impact the Himalayan ecosystem through increased temperature, altered precipitation patterns, episodes of drought and biotic influences. This would not only impact the very sustenance of the indigenous communities in uplands but also the life of downstream dwellers across the country and beyond. Therefore, there is an urgent need for giving special attention to sustain the Himalayan ecosystem. This would require conscious efforts for conserving all the representative systems.
Further, it needs to be emphasized that the endemics with restricted distribution, and most often with specialized habitat requirements, are among the most vulnerable elements. In this respect the Himalayan biodiversity hotspot, with rich endemic diversity, is vulnerable to climate change. The threats include possible loss of genetic resources and species, habitats and concomitantly a decrease in ecosystem services. Therefore, conservation of endemic elements in representative ecosystems/habitats assumes a great significance while drawing conservation plans for the region.
Towards achieving the above, we will have to shift toward contemporary conservation approaches, which include a paradigm of landscape level interconnectivity between protected area systems. The concept advocates a shift from the species-habitat focus to an inclusive focus on expanding the biogeographic range so that natural adjustments to climate change can proceed without being restrictive.
Which one of the following statements best implies the need to shift toward contemporary conservation approach ?
Answer (d) & explanation
The need is to let the Himalaya adapt smoothly (d). Step 1: find why the new approach is wanted. The shift to landscape-level conservation is made "so that natural adjustments to climate change can proceed without being restrictive". Option (d) says exactly this. Step 2: test the others. Option (a) is wrong: resource exploitation is a cause of stress, the problem, not the reason for the new method. Option (b) is wrong: it lists climate impacts, also part of the problem. Option (c) is wrong: rich endemic diversity explains why the region matters, not why the method must change.
Tip: "justify the shift" asks for the purpose of the change. Look for the "so that" clause in the passage.
Answer as per the official UPSC answer key.
A question paper must have a question on one of the eight poets : A, B, C, D, E, F, G or H. The first four belong to the medieval period while the rest are considered modern poets. Generally, modern poets figure in the question paper in alternate years. Generally those who like H like G also; and those who like F like E also. The paper-setter does not like to ask about F as he has written a book on F, but he likes F. Last year, the paper contained a question on A. On the basis of the information given, this year's paper is most likely to contain a question on
Answer (b) & explanation
E is the most likely poet (b). Step 1: last year's paper had A, a medieval poet. Modern poets "generally" come in alternate years, so this year a modern poet is likely: E, F, G or H. Options (a) C is ruled out, as C is medieval. Step 2: the setter likes F but will not ask about F, as he wrote a book on F. So (c) is ruled out. Step 3: "those who like F like E also". The setter likes F, so he likely likes E too, and will choose E. Option (d) H is wrong: nothing says he likes H or G.
Tip: in "most likely" puzzles, use every "generally" rule to narrow choices, then pick the option the clues point to, not one that is merely possible.
Answer as per the official UPSC answer key.
With reference to a grouping of countries known as BRICS, consider the following statements :
- 1. The First Summit of BRICS was held in Rio de Janeiro in 2009.
- 2. South Africa was the last to join the BRICS grouping.
Which of the statements given above is/are correct?
Answer (b) & explanation
Statement 1 is wrong: the first BRIC summit was held at Yekaterinburg, Russia, in 2009, not Rio. Brazil hosted the second, in Brasília in 2010. Statement 2 was correct in 2014: South Africa joined in 2010–11 and turned BRIC into BRICS.
The group has since grown: Egypt, Ethiopia, Iran and the UAE joined in 2024 and Indonesia in 2025. Its New Development Bank (Shanghai) and Contingent Reserve Arrangement were agreed at the Fortaleza summit in 2014. Notice how a question set in one year can age; always read membership questions in the year they were asked.
Answer as of 2014. The expansion from 2024 came after this question was set.
Answer as per the official UPSC answer key.
With reference to the cultural history of India, the term ‘Panchayatan’ refers to
Answer (c) & explanation
A panchayatana temple has a main shrine at the centre with four smaller shrines at the corners of its platform, so it is a style of temple construction (c). The Dashavatara temple at Deogarh and the Kandariya Mahadeva at Khajuraho follow this plan. It is not a village assembly (a), a sect (b) or an official (d), though the word resembles "panchayat".
A related idea is panchayatana puja, popularised by Adi Shankaracharya, which worships five deities together: Shiva, Vishnu, Devi, Surya and Ganesha. Notice how architecture and religious practice mirror each other here.
"Panch" points you towards the village panchayat. Here it means five shrines.
UPSC repeats traps like this year after year. The PYQ Book gathers every trap in one place, so you see them coming. Try the free sample
Answer as per the official UPSC answer key.
Consider the following international agreements :
- 1. The International Treaty on Plant Genetic Resources for Food and Agriculture
- 2. The United Nations Convention to Combat Desertification
- 3. The World Heritage Convention
Which of the above has/have a bearing on the biodiversity?
Answer (d) & explanation
All three bear on biodiversity (d). The Plant Treaty (FAO, 2001) conserves the genetic diversity of crops and shares their benefits (1). The UNCCD (1994) protects drylands and the life they support (2). The World Heritage Convention (1972) protects natural sites such as Kaziranga, Manas and the Western Ghats (3).
These sit with the CBD, CITES, the Ramsar Convention and the Convention on Migratory Species among the biodiversity-related conventions that coordinate their work. Notice how biodiversity is protected not by one treaty but by a web of them, each with its own focus.
Answer as per the official UPSC answer key.
Five persons fire bullets at a target at an interval of 6, 7, 8, 9 and 12 seconds respectively. The number of times they would fire the bullets together at the target in an hour is
Answer (b) & explanation
UPSC's final key accepts both 7 (b) and 8 (c). Step 1: find when all five fire together again. That is the smallest number that 6, 7, 8, 9 and 12 all divide into, the LCM. 8 covers 2 and 4; 9 covers 3; 7 is separate; 6 and 12 are already covered by 8 × 9. So LCM = 7 × 8 × 9 = 504 seconds. Step 2: one hour is 3,600 seconds. 3,600 ÷ 504 = 7 and a bit. So after the first shot they fire together 7 more times, option (b). If you also count the starting shot, it is 8, option (c). The question does not say which, so both were accepted. Options (a) and (d) fit neither count.
Tip: for "together again" questions, always use the LCM, and check whether the start is counted.
The question does not say whether to count the first shot, so UPSC's final key accepts both (b) 7 and (c) 8.
Answer as per the official UPSC answer key.
The following table shows the marks obtained by two students in different subjects :
| Student A | Maximum Marks | Student B | Maximum Marks | |
|---|---|---|---|---|
| English | 60 | 100 | 80 | 150 |
| Psychology | 70 | 100 | 70 | 100 |
| History | 50 | 100 | 60 | 100 |
| Sanskrit | 30 | 50 | 15 | 25 |
The difference in the mean aggregate percentage marks of the students is
Answer (d) & explanation
The difference is zero (d). Step 1: Student A's marks are 60 + 70 + 50 + 30 = 210 out of a maximum of 350. 210 ÷ 350 = 0.6, that is 60%. Step 2: Student B's marks are 80 + 70 + 60 + 15 = 225 out of a maximum of 375. 225 ÷ 375 = 0.6, that is 60%. Step 3: both aggregate percentages are 60%, so the difference is zero. Options (a), (b) and (c) come from adding subject percentages or using the wrong maximum.
Tip: aggregate percentage = total marks obtained ÷ total maximum marks × 100. Do not average the subject-wise percentages when the maximum marks differ.
Add up the marks first, then find one percentage. Do not average the subject percentages.
Answer as per the official UPSC answer key.
Read the passage
Directions : The following six items are based on two passages in English to test the comprehension of English language and therefore these items do not have Hindi version. Read each passage and answer the items that follow.
Passage - 1
In front of us was walking a bare-headed old man in tattered clothes. He was driving his beasts. They were all laden with heavy loads of clay from the hills and looked tired. The man carried a long whip which perhaps he himself had made. As he walked down the road he stopped now and then to eat the wild berries that grew on bushes along the uneven road. When he threw away the seeds, the bold birds would fly to peck at them. Sometimes a stray dog watched the procession philosophically and then began to bark. When this happened, my two little sons would stand still holding my hands firmly. A dog can sometimes be dangerous indeed.
The author's children held his hands firmly because
No official answer (question dropped) & notes
The answer is (a), they were scared of the barking dog. UPSC did not evaluate the six English-only items of 2014 (Q70 to Q75), so this answer is for practice. Step 1: find the line. "Sometimes a stray dog watched the procession philosophically and then began to bark. When this happened, my two little sons would stand still holding my hands firmly." So they held his hands when the dog barked, out of fear. The last line, "A dog can sometimes be dangerous indeed," confirms it. Step 2: test the others. Option (b) is wrong: the berries were eaten by the old man. Option (c) is wrong: the whip is mentioned but did not scare the boys. Option (d) is wrong: the road was uneven, but that is not when they held on.
Tip: "When this happened" points back to the sentence just before it.
UPSC did not evaluate the six English-only items of 2014 (Q70 to Q75), so there is no official key. The answer given in the explanation is for practice.
UPSC dropped this question from evaluation; there is no official answer.
Lichens, which are capable of initiating ecological succession even on a bare rock, are actually a symbiotic association of
Answer (b) & explanation
A lichen is a symbiotic association of a fungus with an alga or a cyanobacterium (b). The fungus provides shelter and holds water; the alga makes food by photosynthesis. Options with bacteria and fungi (c), algae and bacteria (a), or fungi and mosses (d) do not describe a lichen, though some lichens do include cyanobacteria.
Lichens are the pioneers of primary succession on bare rock: their acids slowly weather the rock into the first thin soil, preparing the way for mosses and then larger plants. They are also sensitive to sulphur dioxide, which makes them useful indicators of air pollution.
Answer as per the official UPSC answer key.
What are the benefits of implementing the 'Integrated Watershed Development Programme'?
- 1. Prevention of soil runoff
- 2. Linking the country's perennial rivers with seasonal rivers
- 3. Rainwater harvesting and recharge of groundwater table
- 4. Regeneration of natural vegetation
Select the correct answer using the code given below.
Answer (c) & explanation
A watershed programme treats a whole catchment. Check dams, trenches, bunds and planting stop soil runoff (1 correct), harvest rainwater and recharge groundwater (3 correct), and help regenerate natural vegetation (4 correct). Statement 2 is wrong: linking perennial and seasonal rivers is the separate national Interlinking of Rivers project, not a local watershed activity. So the answer is (c).
The IWMP of 2009 now runs as the Watershed Development Component of PMKSY. Notice how the "ridge to valley" approach treats land and water together: it echoes Ralegan Siddhi and other village success stories.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. ‘Bijak’ is a composition of the teachings of Saint Dadu Dayal.
- 2. The Philosophy of Pushti Marg was propounded by Madhvacharya.
Which of the statements given above is/are correct?
Answer (d) & explanation
Neither statement is correct (d). The Bijak is a collection of the sayings of Kabir and the holy book of the Kabirpanth; Dadu Dayal's verses are gathered in the Dadu Vani. Pushti Marg, the path of grace through loving devotion to Krishna, was taught by Vallabhacharya, not Madhvacharya. Madhvacharya taught Dvaita (dualism).
Vallabhacharya's school is centred on Shrinathji at Nathdwara in Rajasthan, and his philosophy is called Shuddhadvaita. Notice how the Bhakti saints are best learnt with three tags each: philosophy, text and region.
Both statements pair a real text or idea with the wrong saint. Check each name.
Answer as per the official UPSC answer key.
Read the passage
It is essential that we mitigate the emissions of greenhouse gases and thus avoid some of the worst impacts of climate change that would take place in coming years and decades. Mitigation would require a major shift in the way we produce and consume energy. A shift away from overwhelming dependence on fossil fuels is now long overdue, but unfortunately, technological development has been slow and inadequate largely because government policies have not promoted investments in research and development, myopically as a result of relatively low prices of oil. It is now, therefore, imperative for a country like India treating the opportunity of harnessing renewable energy on a large scale as a national imperative. This country is extremely well endowed with solar, wind and biomass sources of energy. Where we have lagged, unfortunately, is in our ability to develop and to create technological solutions for harnessing these resources.
One particular trajectory for carrying out stringent mitigation of greenhouse gas emissions assessed by the Intergovernmental Panel on Climate Change (IPCC) clearly shows the need for ensuring that global emissions of greenhouse gases peak no later than 2015 and reduce rapidly thereafter. The cost associated with such a trajectory is truly modest and would amount, in the estimation of IPCC, to not more than 3 percent of the global GDP in 2030. In other words, the level of prosperity that the world would have reached without mitigation would at worst be postponed by a few months or a year at the most. This is clearly not a very high price to pay for protecting hundreds of millions of people from the worst risks associated with climate change. Any such effort, however, would require lifestyles to change appropriately also. Mitigation of greenhouse gas emissions is not a mere technological fix, and clearly requires changes in lifestyles and transformation of a country’s economic structure, whereby effective reduction in emissions is brought about, such as through the consumption of much lower quantities of animal protein. The Food and Agriculture Organization (FAO) has determined that the emissions from the livestock sector amount to 18 percent of the total. The reduction of emissions from this source is entirely in the hands of human beings, who have never questioned the impacts that their dietary habits of consuming more and more animal protein are bringing about. Mitigation overall has huge co-benefits, such as lower air pollution and health benefits, higher energy security and greater employment.
According to the passage, how does the mitigation of greenhouse gases help us ?
- 1. Reduces expenditure on public health
- 2. Reduces dependence on livestock
- 3. Reduces energy requirements
- 4. Reduces rate of global climate change
Select the correct answer using the code given below :
Answer (b) & explanation
Mitigation helps public health, energy needs and climate change (b). Step 1: find the benefits. Mitigation has "co-benefits, such as lower air pollution and health benefits" (item 1, lower health spending), "higher energy security" (item 3, read by UPSC as reduced energy needs), and it helps "avoid some of the worst impacts of climate change" (item 4). Step 2: test item 2. It is wrong: livestock is a source of emissions to cut by eating less animal protein, not a dependence that mitigation reduces. So options (a), (c) and (d) fail.
Tip: match each option to a phrase in the passage. Item 2 uses a passage word, "livestock", but twists its role.
Answer as per the official UPSC answer key.
As per agreement with a bank, a businessman had to refund a loan in some equal instalments without interest. After paying 18 instalments he found that 60 percent of his loan was refunded. How many instalments were there in the agreement?
Answer (c) & explanation
There were 30 instalments (c). Step 1: 18 instalments cleared 60% of the loan. The instalments are equal and there is no interest, so every instalment clears the same share. Step 2: each instalment clears 60 ÷ 18 = 3⅓%. Step 3: to clear 100%, he needs 100 ÷ 3⅓ = 30 instalments. A faster way: 18 is 60%, so 100% is 18 ÷ 0.6 = 30. Options (a), (b) and (d) do not give 100%.
Tip: this is simple proportion. If 60% takes 18, then 10% takes 3, and 100% takes 30. Breaking it into 10% chunks makes the maths easy without a calculator.
Answer as per the official UPSC answer key.
What are the significances of a practical approach to sugarcane production known as 'Sustainable Sugarcane Initiative'?
- 1. Seed cost is very low in this compared to the conventional method of cultivation.
- 2. Drip irrigation can be practised very effectively in this.
- 3. There is no application of chemical/inorganic fertilizers at all in this.
- 4. The scope for intercropping is more in this compared to the conventional method of cultivation.
Select the correct answer using the code given below.
Answer (b) & explanation
SSI raises single-bud seedlings in a nursery and transplants them with wide spacing. Far less seed cane is needed, so seed cost falls (1 correct). Wide rows suit drip irrigation (2 correct) and leave space for intercropping pulses or vegetables (4 correct). Statement 3 is the odd one out: SSI cuts chemical use through efficient, balanced inputs, but it does not ban fertilizers.
SSI grew out of the System of Rice Intensification (SRI) idea of "less input, more output". Notice how the same logic of spacing, water saving and soil health keeps returning in questions on SRI, micro-irrigation and natural farming.
"no application ... at all". SSI is about efficient inputs, not organic farming.
Answer as per the official UPSC answer key.
Recently, a series of uprisings of people referred to as ‘Arab Spring’ originally started from
Answer (d) & explanation
The Arab Spring began in Tunisia in December 2010, after street vendor Mohamed Bouazizi set himself on fire in protest (d). President Ben Ali fled in January 2011. Protests then spread to Egypt (a), where Hosni Mubarak fell in February 2011, and to Libya, Yemen, Syria (c) and Bahrain. Lebanon (b) was not the starting point.
The outcomes varied widely: Tunisia moved to democracy for a decade, Libya and Yemen slid into conflict, and Syria descended into a long civil war that ended with Assad's fall in December 2024. Notice how food prices, youth unemployment and social media fuelled these protests.
Answer as per the official UPSC answer key.
Which of the following pairs is/are correctly matched?
| Spacecraft | Purpose
| 1. Cassini-Huygens | Orbiting the Venus and transmitting data to the Earth
| 2. Messenger | Mapping and investigating the Mercury
| 3. Voyager 1 and 2 | Exploring the outer solar system
Select the correct answer using the code given below.
Answer (b) & explanation
Pairs 2 and 3 are correct (b). Cassini–Huygens studied Saturn, not Venus, and its Huygens probe landed on the moon Titan in 2005, so pair 1 is wrong. NASA's MESSENGER orbited and mapped Mercury from 2011 to 2015. Voyager 1 and 2, launched in 1977, explored the outer planets and have since entered interstellar space.
Venus missions include Magellan, ESA's Venus Express and Japan's Akatsuki; India plans its Venus Orbiter Mission. Notice how UPSC likes pairing spacecraft with their targets: a short table of missions saves marks.
Answer as per the official UPSC answer key.