Multiple Choice
The temperature coefficient of resistivity of iron is 5.0 * 10-3 / C and that of carbon is -0.50 * 10-3 / C.When an iron wire and a carbon rod, each having the same 10 resistance at 20 C, are cooled from that temperature to -80 C, the new ratio of the resistance of the carbon rod to the resistance of the iron wire at the lower temperature is:
A) (-0.10.)
B) +1.9.
C) +2.1.
D) (-10.)
E) +10.
Correct Answer:

Verified
Correct Answer:
Verified
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