A beam of light has three wavelengths `4144 Å`, `4972 Å` and `6216 Å` with a total instensity of `3.6 xx 10^(-3) Wm^(-2)` equally distributed amongst the three wavelengths. The beam falls normally on an area `1.0 cm^2` of a clean metallic surface of work function 2.3 eV. Assume that there is no loss of light by reflection and that each energetically capable photon ejects on electron. Calculate the number of photo electrons liberated in two seconds.

Options

A. `6 xx 10^11`
B. `9 xx 10^11`
C. `11 xx 10^11`
D. `15 xx 10^11`

Answer

B

Explanation

`9 xx 10^11`