A photocell is illuminated by a small bright source places `1` m away when the same source of light is placed `(1)/(2)` m away. The number of electron emitted by photocathode would be

Options

A. increase by factor of `2`
B. decrease by a factor of `2`
C. increase by a factor of `4`
D. decrease by a factor of `4`

Answer

C

Explanation

`Ialpha1/r^(2)`