Question

Conditions required for photo electric effect

Answer 1

according to classical electromagnetic theory the photoelectric effect can be attributed to the transfer of energy from the light to an electron...below that thesh hold no electrons are emitted from the material regardless of light intensity or the length of time exposure to the light...........

Answer 2

Photoelectric effect

It is the phenomenon of ejection of electrons by certain metals (like potassium, rubidium, caesium etc.) when light of suitable frequency incident on them. The electrons ejected are called photoelectrons. This phenomenon was first observed by H.Hertz. The important characteristics of photoelectric effect are:

1. The electrons are ejected from the metal surface as soon as the beam of light strikes the surface. i.e., there is no time lag between the striking of light beam and the ejection of electrons from the metal surface.

2. The number of electrons ejected is proportional to the intensity or brightness of light.

3. For each metal, there is a minimum frequency (known as threshold frequency ) below which photoelectric effect is not observed.

4. The kinetic energy of the ejected electrons is directly proportional to the frequency of the incident light.