NEET-XII-Physics

42: Photoelectric Effect and Wave Particle Duality

with Solutions - page 2
Qstn# ii-8 Prvs-QstnNext-Qstn
  • #8
    When stopping potential is applied in an experiment on photoelectric effect, no photoelectric is observed. This means that
    (a) the emission of photoelectrons is stopped
    (b) the photoelectrons are emitted but are re-absorbed
    (c) the photoelectrons are accumulated near the collector plate
    (d) the photoelectrons are dispersed from the sides of the apparatus
    digAnsr:   b
    Ans : (b) the photoelectrons are emitted but are re-absorbed by the emitter metal
    In an experiment on photoelectric effect, the photons incident at the metal plate cause photoelectrons to be emitted. The metal plate is termed as "emitter". The electrons ejected are collected at the other metal plate called "collector". When the potential of the collector is made negative with respect to the emitter (or the stopping potential is applied), the electrons emitted from the emitter are repelled by the collector. As a result, some electrons go back to the cathode and the current decreases.
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