Explain Briefly how classical theory could not explain the phenomenon of photoelectric effect

Explanation

To eject an electron from a metal surface, a minimum amount of energy, called the work function of the metal, is required Classically, if incident radiation is a wave its energy is shared by all the atoms in the metal surface and calculation show that it will take almost a year, when the requisite amount of energy may be accumulated by an electron. Hence , on classical picture, The photoelectric emission cannot be instantaneous. When the incident radiation is assumed to be sonsisting of photons, a photon of frequency `v_0` or more can possess the energy needed to eject an electron. If frequency of hte incident photon is less than `v_0`, no photoelectric emission will take place. In a way, `v_0` is cut-off frequency.