## Question

### Solution

Correct option is

310.5 Å, 1242 Å

Let be the wavelength of the incident radiation, W the work function of the surface and the maximum kinetic energy of the emitted photoelectrons. Then When illuminated with light of wavelength , then Substituting eq. (ii) from eq. (i), we get :    = 310.5 Å.

The energy of that photon of maximum wavelength for which photoelectrons can be emitted will be equal to the work function of the surface. Thus    = 10 eV.   .

= 1242 Å.

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