Question

In a plot of photoelectric current versus anode potential, how does
(i) the saturation current vary with anode potential for incident radiations of different frequencies but same intensity?
(ii) the stopping potential vary for incident radiations of different intensities but the same frequency?
(iii) Photoelectric current vary of different intensities but same frequency of incident radiation? justify your answer is each case.

Answer 1

(i) In photoelectric emission from a given metal surface, the saturation current depends on the intensity of the incident radiation but is independent of the frequency of the incident radiation. Therefore, for the radiation of diff. frequency but of same intensity, the value of saturation current will be the same.
(ii) The value of stopping potential for a given metal surface depends on the frequency of the intensity of the incident radiation. Therefore, for the incident radiations of the same frequency but of diff. intensity, the value of stopping potential will be the same.
(iii) The photoelectric current depends on the number of photoelectric emitted, which in turn depends on intensity of incident radiations but is independent of frequency of the incident radiations provided the frequency is more than the threshold frequency for the given metal surface. Therefore, the photoelectric current for the radiations of the same frequency but of different intensity will be different.