why on increasing frequency of incidenting light photon photoelectric current not increases ? how on increasing retarding potential to anode make photoelectric current becomes zero?

Hi rahul,

You see Rahul every photon can only take out only one electron no matter how much enegy it has .If it has extra energy it gives the electron as the kinetic energy.If you increase the frequency you mean that you are increasing the energy of the photon and not the no.of photons so same no .of electrons are emitted same charge is extracted so same photoelectric current.

As the retarding potential increases at anode there will be an opposing electric force on electrons due to the potential and slowly the kinetic energy decreases and thus the velocity of electrons emitted decreases slowly and gradually it reaches zero.Thus the electrons wont flow and current becomes zero.