Question

State the laws of photoelectric effect.

Answer 1

Hint: Photo electric effect is defined as the phenomenon in which electrons (i.e. electrically charged particles) are instantly emitted by the surface of photoelectric material when electromagnetic radiation of certain frequency (i.e. above Threshold Frequency) falls on it.

Complete step by step solution:
Photo electric effect is defined as the phenomenon in which electrons (i.e. electrically charged particles) are instantly emitted by the surface of photoelectric material when electromagnetic radiation of certain frequency (i.e. above Threshold Frequency) falls on it.

The laws governing the photoelectric effect are as follows:
1. Photoelectric effect is an instantaneous process (There is no time lag between the photons hitting the surface of photoelectric material and the emission of electrons from the surface of the material).
2. Photoelectric current is directly proportional to the intensity of light falling on the photoelectric material.
3. Photoelectric current is independent of the frequency of light falling on the photoelectric material.
4. The stopping potential and maximum velocity of the electrons depends upon the frequency light falling on the photoelectric material. It is independent of the intensity of light.
5. The emission of electrons stops below the threshold frequency (Threshold Frequency is defined as the minimum frequency of light required for photoelectric effect to occur)

Note: Photoelectric is composed of Photo (meaning Light) and Electric (meaning flow of electrons). Use this to remember the purpose and usage of Photoelectric Effect.