1997 General Studies, all questions
UPSC Prelims 1997 · General Studies
Question 116: Science and Technology
Which one of the following is used as an anti-freeze for the automobile engines?
aPropyl alcohol
bEthanol
cMethanol
dEthylene glycol
AnswerThe answer is (d).
Ethylene glycol is mixed with water in car radiators because it lowers the freezing point of the coolant well below that of water and also raises its boiling point. It is the standard anti-freeze for engines. Methanol and ethanol also lower the freezing point, but they evaporate easily and catch fire.
Why each option is right or wrong
- (a) Propyl alcohol is not used as an engine anti-freeze.
- (b) Ethanol is flammable and evaporates readily, so it is not the standard choice.
- (c) Methanol is toxic and boils off easily; it is not the standard anti-freeze.
- (d) Right: ethylene glycol.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1997, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.