UPSC Prelims 2008 · General Studies
Question 115: Science and Technology
Mixture of which one of the following pairs of gases is the cause of occurrence of most of the explosions in mines?
AnswerThe answer is (c).
Most mine explosions are caused by firedamp, a mixture of methane and air. Methane seeps out of coal seams, and when its concentration in air is roughly 5 to 15 per cent a spark can set off an explosion. Miners use ventilation, gas detectors and safety lamps to prevent this. Carbon dioxide does not burn, and hydrogen and acetylene are not the usual mine gases.
Why each option is right or wrong
- (a) Hydrogen and oxygen are not the usual mine mixture.
- (b) Acetylene is not the gas found in mines.
- (c) Methane and air (firedamp) cause most mine explosions.
- (d) Carbon dioxide does not burn, so this pair is not the cause.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2008, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.