Light of wavelength 400 nm is incident continuously on a caesium ball ( work function 1.9 eV ). The maximum potential to which the ball will be charged is

Options

A. 3.1V
B. 1.2V
C. zero
D. Infinte

Answer

B

Explanation

(2) `eV_(S)=(hc)/(lambda)-phi=(1240(nm) eV)/(400(nm)) -1.9 eV=1.2 eV`
`rArr V_(S)=1.2 V`
`:.` The cesium ball can be charged to a maximum potential of 1.2 V