In case of photoelectric effect:

Asked by sureshkumar kumar | 8th Jun, 2013, 08:29: PM

Expert Answer:

Frequency means no. of photons hitting per second.
Intensity means no. of photons hitting per unit area.
I think you are mistaken. In the case of photoelectric effect, frequency of the beam affects the number of photons hitting the material per second but intensity does not have a major effect. Increasing the intensity of the light beam increases the number of photons in the light beam, and thus increases the number of electrons excited, but does not increase the energy that each electron possesses. The energy of the emitted electrons does not depend on the intensity of the incoming light, but only on the energy or frequency of the individual photons. It is an interaction between the incident photon and the outermost electron. However, increasing intensity means increasing the number of these photons. And if one photon per electron is needed to induce the photoelectric effect, then you will see higher number of electrons being excited and hence, overall internsity of the light emitted would increase. 

Answered by  | 9th Jun, 2013, 06:23: AM

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