what is the difference between frequency and intensity of light

Asked by lakshmiprasadsingh | 18th Feb, 2014, 07:09: AM

Expert Answer:

The energy of a photon is determined by its frequency, and the intensity of light is determined by the number of photons.

In photoelectric effect, when a photon strikes a metal surface photo electrons are emitted from the surface. Electrons are ejected only if its energy is greater than the work function of the metal. Hence, if the frequency of the light is too low, then it doesn't matter how intense the light is, since the energy of the photon is lower than the work function.

What the intensity does change is the number of photoelectrons emitted. The more photons (Intensity), the more electrons struck and the more that are ejected.

Hence, the energy of emitted electrons is directly proportional to the frequency of the radiation and independent of intensity of the radiation.


Answered by  | 18th Feb, 2014, 11:08: AM

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