Write any three experimental observations of photoelectric effect

Explanation

(i) For a given photosensitive material and frequency of incident radiation (above the threshold frequency), the photosensitive current is directly proportional to the intensity of incident light.
(ii) For a given photosensitive material and frequency of incident radiation, saturation current is proportional to the intensity of incident radiation but stopping potential is independent of its intensity
(iii) For a given photosensitive material, there exists a certain minimum cut-off frequency of the incident radiation called the threshold frequency, below which no photoelectrons emission.
(iv) Above the threshold frequency, the stopping potential or the maximum kinetic energy of the emitted photoelectrons increases linearly with the frequency of the incident radiation, but is independent of its intensity.
(v) The photoelectric emission is an instantaneous process.