Question 295: Dual Nature of Matter and Radiation

Question

The frequency of incident light falling on a photosensitive material is doubled, the K.E. of the emitted photoelectrons will be

Accepted Answer

The kinetic energy of emitted photoelectrons from a photosensitive material is determined by the equation:
$ \mathrm{K.E}_{\max} = \mathrm{h}
u - \mathrm{W} $
When the frequency ($
u$) of the incident light is doubled, the equation becomes:
$ \begin{aligned} \mathrm{K.E}_{\max} & = \mathrm{h}(2
u) - \mathrm{W} \ & = 2\mathrm{h}
u - 2\mathrm{W} + \mathrm{W} \ & = 2(\mathrm{h}
u - \mathrm{W}) + \mathrm{W} \ & = 2\mathrm{K.E}_{	ext{initial}} + \mathrm{W} \end{aligned} $
Thus, the maximum kinetic energy of the emitted photoelectrons is more than twice the initial value.

Answer

unchanged.

Answer

two times its initial value.

Answer

more than two times its initial value.

Answer

less than two times its initial value.

Dual Nature of Matter and Radiation

The frequency of incident light falling on a photosensitive material is doubled, the K.E. of the emitted photoelectrons will be

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