Question

Mention any three features of results of experiment on photoelectric effect which cannot be explained using the wave theory of light.

Hint:

Einstein's explanation of the photoelectric effect relies on the particle theory of light, where light is treated as quanta (photons).

Answer 1

The three features of the photoelectric effect that cannot be explained using the wave theory of light are:
(A) The photoelectric effect occurs instantly when light of a frequency higher than the threshold frequency strikes the metal surface. The wave theory suggests a delay in the emission of electrons.
(B) The kinetic energy of the emitted electrons depends on the frequency of the incident light, not its intensity. Wave theory predicts that the energy should depend on the intensity of light.
(C) The photoelectric effect cannot occur below a certain threshold frequency, regardless of the intensity of light. According to wave theory, there should be no threshold, and intensity should control the emission.