Question

How does quantum theory explain the working of a photocell?

A. Each light wave with a certain minimum energy releases an electron from an atom.

B. Each photon of light with energy below a certain value releases an electron from an atom.

C. Each light wave with energy below a certain value releases an electron from an atom.

D. Each photon of light with a certain minimum energy releases an electron from an atom.

Answer 1

Photocell works on the principle of photoelectric effect in which photon is considered to be having particle nature. In this experiment, photon from the source hits on a metal plate. The photons having energy greater than work function of the metal ejects the electrons from plate. D is correct

Answer 2

The correct option is D.
The mechanism of action of photocell has to do with the interaction of photons with electrons. Generally, when light is incident on an electrode, the incident light will knock loose electrons out of the valence shells of the electrode, the knock out electron will move to the surface of the electrode where it is ejected. This electron is free to move about and to conductor electricity.