3,238 previous year UPSC Prelims (GS Paper-I) questions, from 1995 to 2025, each with the correct answer and a full explanation. Filter by subject, chapter or year.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 801–810 of 3238 questions
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UPSC 2017Geography · Oceanography
Q801. With reference to ‘Indian Ocean Dipole (IOD)’ sometimes mentioned in the news while forecasting Indian monsoon, which of the following statements is/are correct? 1. The IOD phenomenon is characterised by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean. 2.An IOD phenomenon can influence an El Nino’s impact on the monsoon. Select the correct answer using the code given below:
Explanation
Statement 1 is incorrect: The Indian Ocean Dipole(IOD) is defined by the difference in sea surface temperatures (SSTs) between the western and eastern parts of the Indian Ocean, not the Pacific Ocean. Specifically, it involves the SST gradient between the western equatorial Indian Ocean (50°E-70°E and 10°S-10°N) and the southeastern equatorial Indian Ocean (90°E-110°E and 10°S-0°N).
Statement 2 is correct: A positive IOD (warmer SST in the western Indian Ocean) can help mitigate the adverse effects of El Niño on the Indian monsoon by enhancing monsoonal rainfall. Conversely, a negative IOD (warmer SST in the eastern Indian Ocean) can exacerbate El Niño’s drought-like conditions over India.
Exam tip:
For S1, It’s called the Indian Ocean Dipole, so logically, it should involve two regions within the Indian Ocean, not the Pacific. So mentioning the Eastern Pacific is a red flag and likely false. For S2, phrase "can influence" is way too general to be called false. Atmospheric phenomenons are complex and related Hence likely true.
UPSC 2017Science and Technology · Information and Communication Technology
Q802. Which of the following statements is/are correct regarding Smart India Hackathon 2017? 1. It is a centrally sponsored scheme for developing every city of our country into Smart Cities in a decade. 2. It is an initiative to identify new digital technology innovations for solving the many problems faced by our country. 3. It is a programme aimed at making all the financial transactions in our country completely digital in a decade. Select the correct answer using the code given below:
Explanation
Statement 1 is incorrect:
Smart India Hackathon (SIH) 2017 was not a centrally sponsored scheme for developing Smart Cities. It is a nationwide initiative to promote innovation and problem-solving among students by leveraging digital technology. The event was organized by the Ministry of Human Resource Development (MHRD) and the All India Council for Technical Education (AICTE) in collaboration with other government bodies.
Statement 2 is correct: SIH was launched to encourage young minds to develop innovative solutions to challenges faced by ministries, departments, and public sector organizations. It provided a platform for students to collaborate on real-world problems using digital technology.
Statement 3 is incorrect: The Smart India Hackathon is not related to making financial transactions digital. The initiative aimed at promoting digital financial transactions is the Digital India campaign, which includes programs like Unified Payments Interface (UPI), BHIM app, and Aadhaar-enabled payment systems.
UPSC 2017Science and Technology · Information and Communication Technology
Q803. In India, it is legally mandatory for which of the following to report on cyber security incidents? 1. Service providers2. Data centres3. Body corporate Select the correct answer using the code given below:
Explanation
It is legally mandatory for service providers, data centres, and body corporate to report cybersecurity incidents to the Indian Computer Emergency Response Team (CERT-In). Under the Information Technology (IT) Act, 2000, and the Information Technology (The Indian Computer Emergency Response Team and Manner of Performing Functions and Duties) Rules, 2013. CERT-In is the national nodal agency for responding to cybersecurity incidents and ensuring the security of India’s cyber infrastructure.
Additional insight:
The Indian Computer Emergency Response Team (CERT) imposes rules on service providers, intermediaries, data centres, body corporate or persons who provide the information called for or comply with the direction of CERT. They need to report cyber incidents within a reasonable time so that CERT-In may have scope for timely action.
UPSC 2017Environment and Ecology · Pollution
Q804. Biological Oxygen Demand (BOD) is a standard criterion for:
Explanation
BOD measures the amount of dissolved oxygen required by microorganisms to break down organic material in water over a specific time. BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water. It is measured in milligrammes per litre of water of oxygen. The higher value of BOD indicates low (Dissolved Oxygen) DO content of water. BOD is not a reliable method for assessing water pollution because it only includes biodegradable elements.
Additional insight:
Standard Method 5210B is the most widely used method for determining Biological Oxygen Demand (BOD). It measures the difference in dissolved oxygen (DO) over a five-day incubation period at 20°C. The initial DO is recorded, and after incubation, the final DO is measured. The BOD value is then calculated based on oxygen depletion. Higher BOD indicates poor water quality due to higher oxygen demand, while lower BOD suggests purer water with less oxygen consumption. DO levels are lower in summer as warm water holds less oxygen.
UPSC 2017Environment and Ecology · Pollution
Q805. In the context of solving pollution problems, what is/are the advantage/advantages of bioremediation techniques? 1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature. 2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms. 3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation. Select the correct answer using the code given below:
Explanation
Bioremediation is a branch of biotechnology that employs the use of living organisms in the removal of contaminants, pollutants, and toxins from soil, water, and other environments. These organisms can include microbes and bacteria. As a result, compared to other cleanup techniques, bioremediation causes less disruption to the neighbourhood communities.
Statement 1 is correct: Bioremediation uses naturally occurring organisms to break down hazardous substances into less toxic or non-toxic substances.
Statement 2 is incorrect: Not all contaminants are easily treated by bioremediation using microorganisms. For eg. Heavy metals such as cadmium and lead are not readily absorbed or captured by microorganisms.
Statement 3 is correct: The use of genetic engineering to create organisms specifically designed for bioremediation has great potential. For e.g. Alcanivorax, a bacteria with oil-eating abilities, can be used to create species that are much more capable of cleaning oil spills.
Additional insight:
Types of Bioremediation:
Aerobic Bioremediation: Requires oxygen for microbial reactions, where bacteria use a carbon substrate as an electron donor and oxygen as the electron acceptor to break down contaminants. Anaerobic Bioremediation: Occurs in the absence of oxygen, using alternatives like nitrate, sulfate, or carbon dioxide as electron acceptors. Processes include fermentation, methanogenesis, and reductive dechlorination to degrade pollutants. Cometabolic Bioremediation: Microbes degrade contaminants without gaining energy or carbon from them, breaking down pollutants as a side reaction while metabolizing other substances.
Exam tip:
For S2, "Readily and Completely" treated- it is Clearly an extreme phrase, hence very unlikely to be true. If this would have been true, water and soil pollution would have been talk of past, but that’s not the case, hence likely false. Eliminating options B and D.
UPSC 2017Environment and Ecology · Pollution
Q806. It is possible to produce algae based biofuels, but what is/are the likely limitation(s) of developing countries in promoting this industry? 1. Production of algae based biofuels is possible in seas only and not on continents. 2. Setting up and engineering the algae based biofuels production requires high level of expertise/ technology until the construction is complete. 3. Economically viable production necessitates the setting up of large scale facilities which may raise ecological and social concerns. Select the correct answer using the code given below:
Explanation
Biofuels are hydrocarbon fuel that is created in a short amount of time--days, weeks, or even months--from organic matter (living or once-living material). Biofuels may be solid, liquid or gaseous in nature:
Solid: Wood, dried plant material, and manure Liquid: Bioethanol and Biodiesel Gaseous: Biogas
Statement 1 is incorrect: Algaculture (farming algae) can be initiated on land unsuitable for agriculture or saline water or wastewater. Statements 2 and 3 are correct: Producing algae for biofuels (excluding simple seaweed production) requires significant capital investments, which may be a significant barrier in developing countries that have a weak investment climate. Also during the setup stage, the production of algae- based biofuels will necessitate expertise in advanced technology.
Exam tip:
For S1, "seas ONLY" is an extreme absolute phrase and hence unlikely to be true. Thus eliminate options A and D. In contrast, S 2 and S3 are too general and practical to be false, hence more likely to be true.
UPSC 2017Polity · Fundamental Duties
Q807. Which of the following statements is/are true of the Fundamental Duties of an Indian citizen? 1. A legislative process has been provided to enforce these duties. 2. They are correlative to legal duties. Select the correct answer using the code given below:
Explanation
Fundamental Duties are enumerated in Part IV-A and consists of single Article 51A with 11 sub-articles.
Statement 1 is incorrect: Fundamental Duties in the Indian Constitution are outlined in Article 51A (Part IVA) and were added by the 42nd Amendment in 1976. These duties aim to promote a sense of responsibility, unity, and patriotism among Indian citizens. They serve as guidelines for citizens to contribute to the welfare of the nation. But no legislative process has been provided to enforce these duties. These duties are thus non-enforceable and non-justiciable in nature. However, courts have interpreted them as complementary to Fundamental Rights, and certain laws indirectly enforce them. Example: The Prevention of Insults to National Honour Act, 1971 penalizes disrespect to the National Flag and National Anthem, indirectly enforcing Article 51A(a). Example: The Environment Protection Act, 1986 enforces Article 51A(g) (duty to protect the environment).
Statement 2 is incorrect: Fundamental Duties are not legally enforceable duties like legal obligations. They are moral obligations intended to promote civic responsibility and national consciousness, but there are no direct legal consequences for their violation.
Exam tip:
For S2, "Correlative" means they go hand-in-hand -- if you have a legal duty, then you also have a constitutional duty, and vice versa. But that’s not necessarily true. Many legal duties (e.g. paying taxes, obeying traffic laws) exist regardless of Fundamental Duties. And many Fundamental Duties (like developing scientific temper or promoting harmony) are moral/ethical, not legal mandates. Hence S2 likely false.
UPSC 2017Environment and Ecology · Climate Change
Q808. In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be potential sites for carbon sequestration? 1. Abandoned and uneconomic coal seams 2. Depleted oil and gas reservoirs 3. Subterranean deep saline formations Select the correct answer using the code given below:
Explanation
Carbon Sequestration is a process to capture and store CO₂ to curb global warming. It is captured from the air, industries or power stations and stored permanently underground. Terrestrial Carbon Sequestration is the process through which CO₂ from the atmosphere is absorbed by trees and plants through photosynthesis and stored as carbon in soils and biomass (tree trunks, branches, foliage, and roots). In Geologic Carbon Sequestration CO₂ can be stored in oil reservoirs, gas reservoirs, unmineable coal seams, saline formations and shale formations with high organic content.
Statement 1 is correct: Uneconomic coal seams can be used to store CO₂ because the CO₂ molecules attach to the surface of coal.
Statement 2 is correct: CO₂ is sometimes injected into declining oil fields to increase oil recovery.
Statement 3 is correct: Other potential sites are gas reservoirs, saline formations and shale formations with high organic content.
UPSC 2017International Relations and Current Affairs · Current Affairs
Q809. With reference to ‘National Investment and Infrastructure Fund’, which of the following statements is/ are correct? 1. It is an organ of NITI Aayog. 2. It has a corpus of ‘ 4,00,000 crore at present. Select the correct answer using the code given below:
Explanation
Statement 1 is incorrect: NIIF is not an organ of NITI Aayog. It is an independent investment fund set up by the Indian government under the Ministry of Finance. While NITI Aayog plays a role in policy-making, it is not directly involved in managing the NIIF.
Statement 2 is incorrect: NIIF does not have a corpus of ‘4,00,000 crore. The fund was initially set up with a corpus of ‘40,000 crore. The target corpus has been planned to increase over time, but it currently stands much lower than ‘4,00,000 crore.
UPSC 2017Polity · Emergency Provisions
Q810. Which of the following are not necessarily the consequences of the proclamation of the President’s rule in a State? 1. Dissolution of the State Legislative Assembly 2. Removal of the Council of Ministers in the State 3. Dissolution of the local bodies Select the correct answer using the code given below:
Explanation
Statement 1 is correct: As per article 356 of the Constitution of India, the president has the authority to declare if he is satisfied that the state government cannot function in accordance with the Constitution’s provisions. (The President can act on the report of the governor or otherwise). But the ground for Dissolution of the State Legislative Assembly is not necessarily the consequence of proclamation.
Statement 2 is incorrect: When the President’s Rule is imposed in a state, the President dismisses the state council of ministers headed by the chief minister.
Statement 3 is correct: There is no mention of Dissolution of the local bodies during the proclamation of President’s Rule.
Answer key for these questions
Q
UPSC year
Correct answer
801
2017
(b) 2 only
802
2017
(b) 2 only
803
2017
(d) 1, 2 and 3
804
2017
(c) Pollution assay in aquatic ecosystems
805
2017
(c) 1 and 3 only
806
2017
(b) 2 and 3 only
807
2017
(d) Neither 1 nor 2
808
2017
(d) 1, 2 and 3
809
2017
(d) Neither 1 nor 2
810
2017
(b) 1 and 3 only
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This page covers 3238 previous year UPSC Prelims GS Paper-I questions on UPSC Prelims GS Paper-I, asked from 1995 to 2025. Each has the correct answer and an explanation.
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Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
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Questions on UPSC Prelims GS Paper-I are available for 31 years, from 1995 to 2025. Use the Year filter to practise a single paper.
