As per Einstein’s theory of photoelectric effect when a photon strikes the metal surface it ejects an electron. If we increase the intensity of light, the number of photons incident on surface will increase and thus, the number of electrons ejected willincrease proportionally and the photocurrent will also increase. Kinetic energy of ejected electrons is given as
1
2
meve2=eV0 Here, V0 is stopping potential. The stopping potential of surface is constant and it will not increase with increase in intensity of light, so the kinetic energy of ejected electrons will not increase. Thus, increasing the intensity of light will increase the number of photons incident and the kinetic energy will remain unchanged.