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UPSC CSE Prelims 2023 — Science & Technology Questions with Answers

All 11 Science & Technology previous-year questions from UPSC CSE Prelims 2023, each with the correct answer and a full explanation. Practise them as a free, timed mock test with instant scoring.

1. Q1.Science & Technology

   Consider the following statements: Statement-I: India, despite having uranium deposits, depends on coal for most of its electricity production. Statement-II: Uranium, enriched to the extent of at least 60%, is required for the production of electricity. Which one of the following is correct in respect of the above statements?

   • a)Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
   • b)Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
   • c)Statement-I is correct but Statement-II is incorrect
   • d)Statement-I is incorrect but Statement-II is correct
2. Q2.Science & Technology

   Consider the following statements: 1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts. 2. Carbon fibres once used cannot be recycled. Which of the statements given above is/are correct?

   • a)1 only
   • b)2 only
   • c)Both 1 and 2
   • d)Neither 1 nor 2
3. Q3.Science & Technology

   Consider the following actions: 1. Detection of car crash/collision which results in the deployment of airbags almost instantaneously 2. Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive 3. Detection of the tilt of the smart-phone which results in the rotation of display between portrait and landscape mode In how many of the above actions is the function of accelerometer required?

   • a)Only one
   • b)Only two
   • c)All three
   • d)None
4. Q4.Science & Technology

   With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements: 1. Biofilters provide waste treatment by removing uneaten fish feed. 2. Biofilters convert ammonia present in fish waste to nitrate. 3. Biofilters increase phosphorus as nutrient for fish in water. How many of the statements given above are correct?

   • a)Only one
   • b)Only two
   • c)All three
   • d)None
5. Q5.Science & Technology

   Consider the following pairs: Objects in space : Description 1. Cepheids : Giant clouds of dust and gas in space 2. Nebulae : Stars which brighten and dim periodically 3. Pulsars : Neutron stars that are formed when massive stars run out of fuel and collapse How many of the above pairs are correctly matched?

   • a)Only one
   • b)Only two
   • c)All three
   • d)None
6. Q6.Science & Technology

   Which one of the following countries has its own Satellite Navigation System?

   • a)Australia
   • b)Canada
   • c)Israel
   • d)Japan
7. Q7.Science & Technology

   Consider the following statements: 1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket-powered only in the initial phase of flight. 2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile. Which of the statements given above is/are correct?

   • a)1 only
   • b)2 only
   • c)Both 1 and 2
   • d)Neither 1 nor 2
8. Q8.Science & Technology

   'Wolbachia method' is sometimes talked about with reference to which one of the following?

   • a)Controlling the viral diseases spread by mosquitoes
   • b)Converting crop residues into packing material
   • c)Producing biodegradable plastics
   • d)Producing biochar from thermo-chemical conversion of biomass
9. Q9.Science & Technology

   'Aerial metagenomics' best refers to which one of the following situations?

   • a)Collecting DNA samples from air in a habitat at one go
   • b)Understanding the genetic makeup of avian species of a habitat
   • c)Using air-borne devices to collect blood samples from moving animals
   • d)Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies
10. Q10.Science & Technology

    'Microsatellite DNA' is used in the case of which one of the following?

    • a)Studying the evolutionary relationships among various species of fauna
    • b)Stimulating 'stem cells' to transform into diverse functional tissues
    • c)Promoting clonal propagation of horticultural plants
    • d)Assessing the efficacy of drugs by conducting series of drug trials in a population
11. Q11.Science & Technology

    Consider the following heavy industries: 1. Fertilizer plants 2. Oil refineries 3. Steel plants Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries?

    • a)Only one
    • b)Only two
    • c)All three
    • d)None