Question

In a plot of photo electric current v/s anode potential how does
(a) the saturation current varies with anode potential for incident radiations of different frequencies but same intensity.
(b) the stopping potential varies for different intensities but same frequency of incident radiation
(c) photoelectric current varies for different intensities but same frequency of incident radiation?
justify your answer in each case.

Answer 1

(a) when the intensity (I) remains the same but frequencies of the incident radiation change . that means Energy of incident photons change { because we know, E = hv , where v is frequency of incident photons } therefore we can say that energy of emitted photons will be change . therefore, for different anode potential we get different saturation current.

(b) As we know, stopping potential depends upon number of photoelectrons emitted .
if intensity changes , then number of emitted photoelectrons will be change . therefore, stopping potential changes.

(c) photoelectric current is directly proportional to number of emitted photoelectrons .
and number of photoelectrons is directly proportional to the intensity of the incident radiation . that's why photoelectric current varies for different intensities but same frequency of incident radiation .

Answer 2

dont we have to show using graphs