(a) A 5 m length of copper wire at 20°C has a radius of 0.25mm. If a potential difference of 10V is applied across the length of the wire, determine the current in the wire.
(b) If the wire is heated to 50.0°C and the 10 V potential difference is maintained, what is the resulting current in the wire?
a) We can use Ohm's law to determine the current for V = 10 V.
For copper resistivity, r = 1.7à?10^-8 Ohm m,
The resistance is,
R = rl/A ...
Detailed explanations included.