96 previous year UPSC Prelims questions on the UPSC 2013 Prelims. Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 31–40 of 96 questions
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UPSC 2013Art and Culture · Buddhism and Jainism
Q31. Which of the following statements is/are applicable to Jain doctrine? 1. The surest way of annihilating Karma is to practice penance. 2. Every object, even the smallest particle, has a soul. 3. Karma is the bane of the soul and must be ended. Select the correct answer using the codes given below:
Explanation
In Jainism, penance (tapas) is a key practice to purify the soul and annihilate karma. Through austerities, self-discipline, and spiritual practices, Jains believe one can reduce and eventually destroy karmic influences. Jainism teaches that all living beings, as well as non-living objects, possess a form of soul (jiva). This worldview leads to Jains’ strong commitment to ahimsa (non-violence), as every soul, whether human, animal, plant or even minute organisms, is considered sacred. Karma is considered the bane of the soul and must be ended to achieve liberation. Karma is viewed as a powerful force that binds the soul (jiva) to the cycle of birth, death, and rebirth (samsara). The ultimate goal is to achieve liberation (moksha) by ending the influence of karma through right belief, right knowledge, and right conduct.
UPSC 2013Geography · Oceanography
Q32. The most important fishing grounds of the world are found in the regions where:
Explanation
Option (c) is correct: Regions where warm and cold ocean currents meet are highly productive fishing grounds due to:
Plankton Growth: Cold currents bring nutrient-rich deep water, while warm currents stabilize conditions, fostering plankton blooms, the base of the marine food chain. Fish Abundance: These regions attract fish feeding on plankton, creating rich fishing zones like Newfoundland (Labrador Current meets Gulf Stream), North Sea (Gulf Stream meets Arctic currents), and seas near Japan (Kuroshio meets Oyashio).
UPSC 2013Environment and Ecology · Pollution
Q33. Which of the following can be found as pollutants in the drinking water in some parts of India? 1. Arsenic 2. Sorbitol 3. Fluoride 4. Formaldehyde 5. Uranium Select the correct answer using the codes given below.
Explanation
Water Pollution is the contamination of water bodies, usually as a result of human activities. Heavy metal water pollution is the contamination of water with toxic heavy metals, such as lead, mercury, cadmium, arsenic, and chromium etc. Heavy metals can enter the water through natural processes and human activities. Options 1, 3 and 5 are correct: Arsenic, Fluoride, Iron, Uranium, Nitrate, are some major groundwater pollutants in India.
Option 2 is incorrect: Sorbitol is a sugar alcohol found in fruits and plants with diuretic, laxative and cathartic properties. It is not related with drinking water pollution.
Option 4 is incorrect: Formaldehyde is used to preserve fish longer. The use of this chemical is banned in fresh foods by the Food Safety and Standards Authority of India. The International Agency for Research on Cancer (IARC) of WHO classifies formaldehyde as "carcinogenic to humans". Formaldehyde is not established as a drinking water pollutant.
Additional insight:
Water Quality Criteria according to CPCB Drinking Water Source without conventional treatment but after disinfection Total Coliforms Organism MPN/100ml shall be 50 or less pH between 6.5 and 8.5 Dissolved Oxygen 6mg/l or more Biochemical Oxygen Demand 5 days 20C 2mg/l or less Drinking water source after conventional treatment and disinfection Total Coliforms Organism MPN/100ml shall be 5000 or less pH between 6 to 9 Dissolved Oxygen 4mg/l or more Biochemical Oxygen Demand 5 days 20C 3mg/l or less
UPSC 2013Environment and Ecology · Pollution
Q34. Due to improper/indiscriminate disposal of hold and used computers or their parts, which of the following are released into the environment as e-waste? 1. Beryllium 2. Cadmium 3. Chromium 4. Heptachlor 5. Mercury 6. Lead 7. Plutonium Select the correct answer using the codes given below:
Explanation
E-waste is any electrical or electronic equipment that’s been discarded. Recently, India’s first e-waste clinic was inaugurated in Bhopal. E-waste Sources Constituents PCBs, glass panels, and Computer monitors Lead Resistors & Semiconductors Cadmium Relays and switches, &PCBs Mercury Galvanised steel plates & decorator or hardener Chromium Cabling, Computer & housing Plastics & PVC Electronic equipments & circuit boards Brominated flame-retardants Front panels of CRTs Barium, Phosphorus & Heavy metals Copper wires, PCB tracks Copper Nickel Cadmium batteries Nickel Lithium-ion battery Lithium Motherboards Beryllium Options 1, 2, 3, 5 and 6 are correct: All elements in these options are the harmful constituents that are released into the environment due to improper disposal of e-waste.
Option 4 is incorrect: Heptachlor is a pesticide classified under Persistent Organic Pollutants (POPs) per the Stockholm Convention. It is unrelated to e-waste.
Option 7 is incorrect: Plutonium, while used in some industrial and military applications, is a radioactive material and is not classified as part of e-waste.
UPSC 2013Environment and Ecology · Pollution
Q35. Acid rain is caused by the pollution of environment by
Explanation
Normal rain has a pH of about 5.6 when pH falls below this; it is called Acid rain (pH 4.2 to 4.4). Acid rain results when Sulphur Dioxide (SO₂) & Nitrogen Oxides (NOX) react with water, oxygen & other chemicals to form Sulfuric & Nitric acids. NOx + SO₂ + Moisture + other chemicals Acid Rain (HNO₃ + H₂ SO₄) Acid rain harms microorganisms in the soil; inhibits the activity of nitrogen fixation bacteria; soil acidification; ocean acidification; affects the growth of plants; food chain; kills aquatic animals; corrosion of metals and weathering of stone buildings & statues.
UPSC 2013Environment and Ecology · Pollution
Q36. Photochemical smog is a resultant of the reaction among
Explanation
Photochemical smog, often referred to as "Los Angeles smog," is most commonly found in urban areas with high numbers of automobiles. It does not require smoke or fog to form. This type of smog is formed from the nitrogen oxides and hydrocarbon (peroxyacetyl nitrate, a hazardous pollutant) vapors released by vehicles and other sources, which then undergo photochemical reactions in the lower atmosphere in the presence of sunlight.
UPSC 2013Environment and Ecology · Pollution
Q37. Improper handling and storage of cereal grains and oilseeds result in the production of toxins known as aflatoxins which are not generally destroyed by the normal cooking process. Aflatoxins are produced by:
Explanation
Aflatoxins are produced by certain species of fungi (moulds), specifically Aspergillus flavus and Aspergillus parasiticus, which often grow on stored grains and oilseeds under conditions of high humidity and temperature. Exposure to aflatoxins can lead to serious health issues, including liver cancer, especially in children. Beyond health risks, aflatoxins cause significant economic losses, with an estimated 25% of global food crops affected annually.
UPSC 2013Polity · Constitutional Amendment
Q38. Consider the following statements: 1. An amendment to the Constitution of India can be initiated by an introduction of a bill in the Lok Sabha only. 2. If such an amendment seeks to make changes in the federal character of the Constitution, the amendment also requires to be ratified by the legislature of all the States of India. Which of the statements given above is/are correct?
Explanation
Statement 1 is incorrect: An amendment of the Constitution can be initiated by the introduction of a bill in either house of the Parliament. (not only in Lok Sabha).
Statement 2 is incorrect: If the bill seeks to amend the Federal provisions of the Constitution, then it must also be ratified by the legislatures of half of the states by a simple majority and not all the states.
UPSC 2013Geography · Geomorphology
Q39. Which of the following statements regarding laterite soils of India are correct? 1. They are generally red in colour. 2. They are rich in nitrogen and potash. 3. They are well-developed in Rajasthan and UP. 4. Tapioca and cashew nuts grow well on these soils. Select the correct answer using the codes given below:
Explanation
Statement 1 is correct: The distinctive red colour is one of the key characteristics of laterite soils. It appears red due to the high concentration of iron oxides. In tropical climates, heavy rainfall causes intense leaching, washing away silica and other bases while leaving behind iron and aluminum oxides, which give the soil its distinctive red color.
Statement 2 incorrect: Laterite soils are poor in nitrogen, phosphorus, and potash (potassium). The intense leaching caused by heavy rainfall in tropical regions washes away these soluble nutrients.
Statement 3 is incorrect: Laterite soils are primarily found in the humid tropical regions of India, such as the Western Ghats, parts of Eastern Ghats, and some northeastern states. Rajasthan and Uttar Pradesh (UP) have a drier climate which is not suitable for the formation of laterite soils.
Statement 4 is correct: The agro-climatic conditions of laterite soils support the cultivation of crops such as tapioca, cashew nuts, groundnut, coffee, and rubber. These crops are well-adapted to the moisture-retaining and nutrient-poor nature of laterite soils.
UPSC 2013Geography · Geomorphology
Q40. Consider the following statements: 1. Natural gas occurs in the Gondwana beds. 2. Mica occurs in abundance in Kodarma. 3. Dharwars are famous for petroleum. Which of the statements given above is/are correct?
Explanation
Statement 1 is incorrect: The Gondwana beds are primarily famous for containing coal reserves, with nearly 98% of India’s coal reserves found in them. They are not significant for natural gas reserves. Natural gas in India is more commonly associated with other formations such as sedimentary basins such as the Cambay Basin or the Krishna-Godavari Basin.
Statement 2 is correct: Kodarma in Jharkhand is a well-known region for mica production, which has been an important mineral in India’s mineral resources. Mica is found abundantly here and Kodarma is often referred to as the "mica capital" of India.
Statement 3 is incorrect: The Dharwar system of rocks is not known for petroleum production. The Dharwar rocks are particularly valuable for metallic minerals like high-grade iron ore, manganese, and copper. Petroleum is not found in the Dharwar rock system but in other formations like the Cambay Basin or the Rajasthan Basin.
Answer key for these questions
Q
UPSC year
Correct answer
31
2013
(d) 1, 2 and 3
32
2013
(c) Warm and cold oceanic currents meet
33
2013
(c) 1, 3 and 5 only
34
2013
(b) 1, 2, 3, 5 and 6 only
35
2013
(d) nitrous oxide and sulphur dioxide
36
2013
(a) NO₂, O₃ and peroxyacetyl nitrate in the presence of sunlight
37
2013
(c) moulds
38
2013
(d) Neither 1 nor 2
39
2013
(c) 1 and 4
40
2013
(b) 2 only
Frequently asked questions
How many previous year UPSC questions are there on all subjects?
This page covers 96 previous year UPSC Prelims GS Paper-I questions on the UPSC 2013 Prelims, asked from 1995 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
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.
Which years are covered for all subjects?
Questions on the UPSC 2013 Prelims are available for 31 years, from 1995 to 2025. Use the Year filter to practise a single paper.