The General class exam question of the week is from sub-element 6 (circuit components) section A (resistors) [G6A06]
What will happen to the resistance if the temperature of a resistor is increased?
A. It will change depending on the resistor’s reactance coefficient
B. It will stay the same
C. It will change depending on the resistor’s temperature coefficient
D. It will become time dependent
The answer is C. It will change depending on the resistor’s temperature coefficient. That number basically defines how the material in the resistor reacts to temperature.
A resistor doesn’t have a “reactance coefficient”, as reactance is a property of circuits and elements that respond to AC (Alternating Current.) It might be measured in Ohms, but the resistor doesn’t particularly care either way.
Staying the same would be ideal, but that is never the case. And becoming “time dependent” really doesn’t make sense here, unless you’re applying heat, in which case the temperature would continue to increase…. but the resistor’s response to that temperature would still be defined by the temperature coefficient.