(a) Draw a graph showing the variation of photoelectric current with collector plate potential for two different frequencies of the incident radiation.
(b) Write Einstein's photoelectric equation. Explain two features of photoelectric effect cannot be explained by wave theory of light.
(a)
(b) Einstein photoelectric equation is given by;
where
h - Plank's constant
- Frequency of light
- work function
- maximum kinetic energy
Features of photoelectric effect which cannot be explained by the wave theory of light.
(i) The kinetic energy of emitted electrons is found to be independent of the intensity of incident light.
(ii) The electrons are emitted only at a particular frequency called threshold frequency. Below that frequency, no photoemission takes place.