Question

To keep the electric current flowing in a conductor continuously we need to maintain a constant difference across its terminals.

• A. Temperature
• B. charge density
• C. pressure
• D. electric potential

Answer 1

The correct option is D electric potential

To maintain a current you need to maintain the electric field inside a conductor. Only then will the electrons move in the forward direction. For that a potential difference across the conductor is required. We know $E=\frac{dv}{dr}$, so if dv =0 (i.e. potential difference is zero) there can’t be an electric field and hence no current. Therefore, a potential difference is must.