Question

Of what material is a resistor made if its resistance is 40.0% greater at 100ºC than at 20.0ºC?

a) Tungsten
b) Copper
c) Aluminum
d) Carbon

Answer 1

To find the material of a resistor with a 40.0% increased resistance from 20.0°C to 100.0°C, one must match the temperature coefficient of resistivity to the materials given. Carbon is unlikely due to its lower temperature coefficient.

Step-by-step explanation:

The question involves determining the material of a resistor based on the change in its resistance due to a temperature increase. The key is to identify which material has a temperature coefficient of resistivity that corresponds to a 40.0% increase when the temperature changes from 20.0°C to 100.0°C. Among the options given, tungsten and copper typically show a significant change in resistance with a temperature increase, but carbon shows a relatively small change, and therefore is an unlikely candidate. Aluminum's resistance also changes with temperature, but its temperature coefficient of resistivity is different from the figures given in the question.