According to the wave theory of radiation, the greater the intensity, the greater are the amplitude of electric and magnetic fields. consequently, the greater the intensity the greater should be the energy absorbed by each electron. In this picture, the maximum K.E of the photoelectrons is then expected to increase with an increase in intensity, but it is contrary to the experimentally observed fact.
According to wave theory, electrons should always be emitted from as metal by radiation of any frequency if the incident beam more intense. A threshold frequency, therefore should not exist. This is just opposite to photoelectric effect observation.
According to wave theory, the energy of radiation is spread over the wavefront of the radiation. Therefore, a single electron in the metal will intercept only a small fraction of the wave’s energy. Consequently, considerable time would be needed for an electron to absorb enough energy from the wave to escape the metal’s surface. But experiments show that photoelectric emission is instantaneous, there is no delay.
i.e we can say that wave picture is unable to explain the most basic features of photoelectric emission.
| Introduction | Electron Emission |
| Photoelectric Effect | Experimental Study of Photoelectric Effect |
| Photoelectric Effect and Wave Theory of Light | Einstein’s Photoelectric Equation: Energy Quantum of Radiation |
| Particle Nature of Light: The Photon | Wave Nature of Matter |
| Davisson and Germer Experiment | |