Current Electricity and Electrical InstrumentHard
Question
A strip of copper and another germanium are cooled from room temperature to 80 K. The resistance of
Options
A.each of these decreases
B.copper strip increases and that of germanium decreases
C.copper strip decreases and that of germanium increases
D.each of these increases.
Solution
The temperature coefficient of resistance of copper is positive and that of germanium is negative, therefore when copper and germanium are cooled, resistance of copper strip decreases and that of germanium increases.
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