Question

A photon of energy 4 eV is incident on a metal surface whose work function is 2 eV. The minimum reverse potential to be applied for stopping the emission of electrons is

(a) 2 V

(b) 4 V

(c) 6 V

(d) 8 V

Answer 1

The correct option is (a) 2 V.

Explanation:

When stopping potential is applied no electron will reach the cathode and the current will becomes zero.