Question

On a photosensitive material, when frequency of incident radiation is increased by 30% kinetic energy of emitted photoelectrons increases from `0.4 eV` to `0.9 eV`. The work function of the surface is
A. 1eV
B. 1.267eV
C. 1.4eV
D. 1.8eV

Answer 1

Correct Answer - B
`hv=0.4+W_(0) .....(i)`
`1.3 hv=0.9+W_(0) .....(ii)`
(ii)-1.3 (i) gives
`0.3 W_(0)=0.9-1.3 (0.4)`
`therefore W_(0)=(0.38)/(0.3)=1.267eV`