Explain effect of potential on photoelectric current.

Explanation

Photoelectric effect is the phenomenon of emission of electrons by certain substances when they are illuminated by radiations like X-rays, ultraviolet rays and even visible light.

Variation of Stopping Potential with the frequency of the incident radiation. Take radiations of different frequencies, say of `v_(1), v_(2),v_(3)` ... but of the same intensity. Study variation of photoelectric current and potential of plate Q for each frequency and plot. A graph as shown in the figure will be observed. If `v_(3) gt v_(2) gt v_(1)` the stopping potential `V_(3)` will-be observed to be most negative and `V_(1)` the least negative. This means higher the frequency higher the energy of photoelectrons and more the negative have potential to be applied to stop it.