UPSC Prelims Practice Questions — Govt. amends rules to enable use of E100 in compliant vehicles

Q1. With reference to flex-fuel vehicles and the recent amendment of the Central Motor Vehicles Rules, 1989 enabling E100, consider the following statements: Which of the statements given above is/are correct?

  1. A vehicle certified as compatible with E20 petrol is, for that reason, also suitable for E85, since both are ethanol-petrol blends.
  2. Under the amended rules, E85 and E100 may be used only in vehicles that manufacturers have designed as flex-fuel vehicles.
  3. A flex-fuel vehicle is designed to run on petrol alone as well as on ethanol blends of varying strength, up to pure ethanol.
  • A. 1 and 3 only
  • B. 1 and 2 only
  • C. 2 and 3 only
  • D. 3 only

Q2. Consider the following statements: Which of the following is correct in respect of the above statements?

  1. A petrol vehicle built to run on E10 or E20 cannot be assumed fit to run on E85 or E100.
  2. At high concentrations, ethanol requires a different engine calibration and fuel-system materials, which vehicles not designed as flex-fuel vehicles lack.
  • A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
  • B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  • C. Statement-I is correct, but Statement-II is incorrect
  • D. Statement-I is incorrect, but Statement-II is correct

Q3. Consider the following statements about the instruments governing ethanol use in India: Which of the statements given above is/are correct?

  1. The 20% ethanol blending target was advanced by a Union Cabinet decision amending the National Policy on Biofuels, 2018, without Parliament enacting a law for it.
  2. The National Policy on Biofuels is the legal instrument under which emission standards for vehicles running on ethanol blends are notified.
  3. The use of E100 in vehicles was enabled by amending the rules on vehicle emission standards and testing, not by amending the biofuel policy.
  • A. 1 and 3 only
  • B. 1 and 2 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q4. Consider the following statements: Which of the following is correct in respect of the above statements?

  1. India advanced its target of 20% ethanol blending in petrol from 2030 to Ethanol Supply Year 2025-26.
  2. The 2022 amendment to the National Policy on Biofuels narrowed the range of feedstocks permitted for biofuel production to protect food security.
  • A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
  • B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  • C. Statement-I is correct, but Statement-II is incorrect
  • D. Statement-I is incorrect, but Statement-II is correct

Q5. With reference to generations of ethanol in India, consider the following statements: Which of the statements given above is/are correct?

  1. Second-generation ethanol is produced from lignocellulosic biomass such as agricultural residues.
  2. Ethanol from B-heavy molasses counts as second-generation ethanol because molasses is a by-product of sugar manufacture.
  3. PM JI-VAN Yojana provides financial support to integrated bio-ethanol projects based on lignocellulosic biomass and other renewable feedstock.
  • A. 1, 2 and 3
  • B. 2 and 3 only
  • C. 1 only
  • D. 1 and 3 only

Q6. India has now permitted E85 and E100 in flex-fuel vehicles. If the extra ethanol needed for wider use of such fuels came mainly from sugarcane and cereal grains, which of the following would be the most likely consequence?

  • A. A shift in the ethanol supply away from first-generation towards second-generation routes
  • B. Greater competition for cropland and irrigation water between edible and energy uses
  • C. A fall in demand among vehicle manufacturers for engines with flex-fuel capability
  • D. A rise in the crude oil import requirement for each litre of transport fuel consumed

Q7. With reference to ethanol as a transport fuel, consider the following statements: Which of the statements given above are correct?

  1. Since ethanol is derived from biomass, burning it in an engine releases no carbon dioxide at the tailpipe.
  2. Ethanol has a higher octane rating than petrol, so blending it in improves the fuel's resistance to engine knocking.
  3. The drop in fuel economy with E20 is roughly equal to the full calorific-value gap between pure ethanol and petrol.
  4. Ethanol carries less energy per litre than petrol, so blending can lower mileage in vehicles not optimised for it.
  • A. 2 and 4 only
  • B. 2, 3 and 4 only
  • C. 1 and 3 only
  • D. 1, 2 and 4 only

Q8. Consider the following assertion: The October 2026 amendment adding E100 to the Central Motor Vehicles Rules, 1989 is enabling rather than mandatory in nature. Which of the statements given below support/supports the above assertion?

  1. It does not require owners of existing vehicles to switch to higher ethanol fuels or to modify their vehicles.
  2. Actual use of E100 depends on manufacturers bringing out flex-fuel models and on the fuel being available.
  3. Under the amended rules, E100 means fuel of 100% ethanol, subject to the applicable fuel specification.
  • A. 1 only
  • B. 1 and 2 only
  • C. 1, 2 and 3
  • D. 2 and 3 only