The factor on which the number of photoelectrons emitted per unit time depends in the photoelectric effect is:

Options

A. Energy of incident radiations
B. Frequency of incident radiations
C. Intensity of incident radiations
D. Both frequency and intensity of incident radiation

Answer

C

Explanation

Results observed in the photoelectric effect experiment:
(i) 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.
(ii) The number of electrons ejected is proportional to the intensity or brightness of light.
(iii) For each metal, there is a characteristic minimum frequency, also known as threshold frequency below which photoelectric effect is not observed.