UPSC Prelims 1998 · General Studies
Question 113: Science and Technology
Consider the following statements about acetylene: I. It is used in welding industry. II. It is raw material for preparing plastics. III. It is easily obtained by mixing silicon carbide and water. Of these statements:
AnswerThe answer is (a).
Acetylene burns with oxygen in the oxy-acetylene flame at above 3000 degrees C, which is used for welding and cutting metals. It is also a raw material for plastics and synthetic fibres, through compounds such as vinyl chloride. It is obtained by adding water to calcium carbide, not silicon carbide, so III is wrong.
- I. The oxy-acetylene flame is used for welding.
- II. It is a raw material for plastics such as PVC.
- III. It is made from calcium carbide and water, not silicon carbide.
Why each option is right or wrong
- (a) Right: I and II are correct.
- (b) III is wrong: acetylene comes from calcium carbide.
- (c) III is wrong, and it leaves out I.
- (d) III is wrong, so not all three are correct.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1998, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.