Question

A uniform conducting rod of length 34 cm has a potential difference across its ends equal to 39 mV (millivolts). What is the magnitude of the electric field inside the conductor in units of N/C?

Answer 1

Electric field is the change in voltage per unit distance\[E=\frac{\Delta V}d\]we know the potential difference DeltaV, and the distance over which it occurs (the length of the rod) so you can just plug in and solve.