1)

 Let the energy of an emitted photoelectron be E and wavelength of incident light be $\lambda$. What will be the change in E if $\lambda$ is doubled?


A) E

B) E/2

C) 2E

D) E/4

Answer:

Option B

Explanation:

We have 

 hv= W0+E, where E is the energy of emitted photoelectron

$\Rightarrow \frac{hc}{\lambda}=W_{0}+E$

 As hc and W0 are constant

$E\propto \frac{1}{\lambda}$

 Therefore, as $\lambda$  is doubled, E will become half