NEET-XII-Physics

42: Photoelectric Effect and Wave Particle Duality

with Solutions - page 3
Qstn# iii-3 Prvs-QstnNext-Qstn
  • #3
    A photon of energy hv is absorbed by a free electron of a metal with work-function hv - φ.
    (a) The electron is sure to come out.
    (b) The electron is sure to come out with kinetic energy hv - φ.
    (c) Either the electron does not come out or it comes our with kinetic energy hv - φ.
    (d) It may come out with kinetic energy less than hv - φ.
    digAnsr:   d
    Ans : (d) It may come out with kinetic energy less than hv - φ.
    When light is incident on the metal surface, the photons of light collide with the free electrons. In some cases, a photon can give all the energy to the free electron. If this energy is more then the work-function of the metal,then there are two possibilities. The electron can come out of the metal with kinetic energy hv - φ or it may lose energy on collision with the atoms of the metal and come out with kinetic energy less than hv - φ. Thus, it may come out with kinetic energy less than hv - φ.
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