Light of wavelength L falls on a metal surface with intensity X and the metal emits Y electrons per second of average energy Z. what happens to Y and Z if L is halved????
For a given metal, the number of electrons ejected per second is directly proportional to the intensity of the incident light. Since there is no change in the intensity hence, Y will not change on changing L.
Above the threshold frequency, the maximum kinetic energy of emitted electrons is independent of the intensity of the incident light but depends only on the frequency (or wavelength) of the incident light.
Wavelength (L) is halved means that the frequency is doubled since frequency is inversely proportional to wavelength. Hence, the energy of emitted electrons will become twice since it depends upon the frequency of incident light.
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