(ii) For a given photosensitive material and frequency of incident radiation,
saturation current is found to be proportional to the intensity of
incident radiation whereas the stopping potential is independent of
its intensity (Fig 11 3) (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 emission of photoelectrons takes place,
no matter how intense the incident light is