UPSC 2012 Science and Technology Questions with Answers
13 previous year UPSC Prelims questions on Science and Technology in the UPSC 2012 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 11–13 of 13 questions
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UPSC 2012Science and Technology · Miscellaneous
Q11. To meet its rapidly growing energy demand, some opine that India should pursue research and development on thorium as the future fuel of nuclear energy. In this context, what advantage does thorium hold over uranium? 1. Thorium is far more abundant in nature than uranium. 2. On the basis of per unit mass of mined mineral, thorium can generate more energy compared to natural uranium. 3. Thorium produces less harmful waste compared to uranium. Which of the statements given above is/are correct?
Explanation
Statement 1 is correct: Thorium composes 0.0006% of the earth’s crust whereas Uranium composes 0.00018% of the earth’s crust, where a substantial amount of Uranium is found in dissolved seawater. Thus, Thorium(Th) is comparatively far more abundant in nature than uranium(U).
Statement 2 is correct: Uranium-233, produced from thorium, is generally considered to have higher energy output compared to natural uranium, with estimates suggesting it could produce significantly more energy per unit mass, though the exact ratio can vary depending on reactor design and conditions.
Statement 3 is correct: Thorium-based reactors generate less long-lived radioactive waste compared to uranium-based reactors. The waste from thorium has a lower proportion of transuranic elements like plutonium, which are highly radioactive and pose disposal challenges."
UPSC 2012Science and Technology · Miscellaneous
Q12. Which one of the following sets of elements was primarily responsible for the origin of life on the Earth?
Explanation
Biologists studying various forms of life on Earth have identified a common characteristic among all living organisms. The matter within every living organism on Earth primarily consists of four chemical elements: hydrogen, oxygen, carbon, and nitrogen.
Option (b) is correct: Carbon, hydrogen, and nitrogen are the elements that were primarily responsible for the origin of life on Earth. These elements are fundamental in the formation of organic compounds, such as proteins, nucleic acids, and lipids, which are essential for life. The combination of carbon, hydrogen, and nitrogen forms the basis of amino acids, nucleotides, and other critical biomolecules involved in the origin of life on Earth.
UPSC 2012Science and Technology · Miscellaneous
Q13. Consider the following statements: If there were no phenomenon of capillarity 1. It would be difficult to use a kerosene lamp. 2. One would not be able to use a straw to consume a soft drink. 3. The blotting paper would fail to function. 4. The big trees that we see around would not have grown on the Earth. Which of the statements given above are correct?
Explanation
Capillarity (or capillary action) is the ability of a liquid to flow in narrow spaces, such as thin tubes or porous materials, without the assistance of external forces and even against gravity. It occurs due to the cohesion (attraction between liquid molecules) and adhesion (attraction between the liquid and solid surface), along with surface tension.
Statement 1 is correct: The oil in the wick of a lamp rises due to the capillary action of threads in the wick. Absence of capillarity would certainly make it difficult to use Kerosene lamps.
Statement 2 is incorrect: There is no capillary action in using a straw to consume the soft drink as the consumer applies additional pressure from the mouth to consume the soft drink.
Statement 3 is correct: A blotting paper soaks ink by the capillary action of the pores in the blotting paper. The blotting paper will not be useful without the capillarity phenomenon.
Statement 4 is correct: The root-hairs of plants draw water from the soil through capillary action. Therefore absence of capillarity phenomenon would adversely affect the growth of trees.
Answer key for these questions
Q
UPSC year
Correct answer
11
2012
(d) 1, 2 and 3
12
2012
(b) Carbon, Hydrogen, Nitrogen
13
2012
(b) 1, 3 and 4 only
Frequently asked questions
How many previous year UPSC questions are there on Science and Technology?
This page covers 13 previous year UPSC Prelims GS Paper-I questions on Science and Technology in the UPSC 2012 Prelims, asked from 1996 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 Science and Technology?
Questions on Science and Technology in the UPSC 2012 Prelims are available for 30 years, from 1996 to 2025. Use the Year filter to practise a single paper.
