As per the wave theory, the maximum kinetic energy of the photoelectron should be affected by the change in intensity. But, the experiments on photoelectric effect showed that maximum kinetic energy doesn’t depend on the change in intensity. So, this was the first inconsistency of the wave theory with the experiments.
Wave theory didn’t talk about the relation between stopping potential and the threshold frequency.It said only increasing the intensity could overcome the stopping potential. Here came the second inconsistency of wave theory with the experimental results.
According to the wave theory, photoelectric effect was not aninstantaneous process, it was time taking. This was the third inconsistency with the experiments.
The above three inconsistencies showed that wave theory of light could not explain the experimentally observed characteristics of photoelectric effect.