2007 General Studies, all questions
UPSC Prelims 2007 · General Studies
Question 122: Science and Technology
Which one of the following does not contain silver?
aHorn Silver
bGerman Silver
cRuby Silver
dLunar Caustic
AnswerThe answer is (b).
German silver is an alloy of copper, zinc and nickel and contains no silver at all. Horn silver is silver chloride (AgCl), ruby silver is the ore pyrargyrite (a silver antimony sulphide), and lunar caustic is silver nitrate (AgNO3), so all three contain silver.
Why each option is right or wrong
- (a) Horn silver is silver chloride.
- (b) Correct: German silver has copper, zinc and nickel, no silver.
- (c) Ruby silver is a silver-antimony sulphide ore.
- (d) Lunar caustic is silver nitrate.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2007, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.