Q.13. A light beam of wavelength 400 nm is incident on a metal plate of work function 2.20 eV. (a) A particular electron absorbs a photon and makes two collisions before coming out of the metal. Assuming that 10% of the energy excess of the average energy of other electrons is lost to the metal in each collision, find the kinetic energy of the electron as it comes out of the metal. (b) Under the same assumption, find the maximum number of collisions the electron can suffer and still be able to come out of the metal.