2006 General Studies, all questions
UPSC Prelims 2006 · General Studies
Question 128: Science and Technology
Which are the materials generally employed as solder in soldering operation in electronics?
aIron and tin
bLead and tin
cAluminum and lead
dAluminum and iron
AnswerThe answer is (b).
Solder is a low-melting alloy of tin and lead used to join electronic components, commonly in ratios such as 60:40 or 63:37, because it melts at a low temperature and flows to form a good electrical joint. Iron and aluminium melt at much higher temperatures and are poor for soldering. Lead-free solders are now used in many places.
Why each option is right or wrong
- (a) Iron melts at too high a temperature.
- (b) Correct: lead and tin.
- (c) Aluminium is hard to solder and melts high.
- (d) Aluminium and iron are unsuitable for soldering electronics.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2006, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.