Photons of frequency v fall on a metal surface for which the threshold frequency is $v_0$. Then,
Answer & explanation
Correct answer: option 2
After taking energy from photon a electron goes through many collisions and hence loses its energy. If loss of energy is such that the energy remains with the electron is less than $h\nu_0$ then electron will not come out of metal surface. Hence energy with the electron coming out of the metal surface can vary between zero to a maximum value of $h(\nu - \nu_0)$.