Stopping potential or cut-off potential is defined as the required potential for stopping the removal of an electron from a metal surface when the incident light energy is greater than the work potential of the metal on which the incident light is focused.
- Stopping potential does not depend on the intensity of incident radiation. On increasing intensity, the value of saturated current increases, whereas the stopping potential remains unchanged.
- For a given intensity of radiation, the stopping potential depends on the frequency. Higher the frequency of incident light higher the value of stopping potential.