A long copper wire is connected to an ideal battery that maintains a constant…
PHYSICS · Single correct · CBSE · Physics · Current Electricity · Current Electricity
Problem
A long copper wire is connected to an ideal battery that maintains a constant potential difference across the wire. After several minutes, the wire has warmed to a higher uniform temperature. Which of the following best explains what happens to the current in the circuit as the wire warms?
(a) The current increases because the charge carriers move faster at the higher temperature.
(b) The current remains essentially the same because the battery maintains a constant potential difference across the wire.
(c) The current decreases because the wire’s resistance increases when its temperature rises.
(d) The current increases because thermal expansion makes the wire slightly thicker, reducing its resistance.