Question

14. Electrons are constantly in motion within metals but there is no currents until a potential difference, is established across 1 because :
(A) Electrons do not take part in conduction of current.

(B) Electrons become only free when potentialdifference is applied across the conductor.

(C) Electrons move from one point to another only when potential difference is applied across thevconductor

(D) None of these​

Answer 1

The electrons are in random motion inside a conductor. Their average velocity sums up to 0 and hence there is no current inside the conductor till a potential difference is applied. on applying a voltage, the electrons start moving in a fixed direction that leads to current in the conductor.