Monochromatic light of frequency `6xx10^(14)Hz` is produced by a laser. The power emitted is `2xx10^(-3)` W.
The number of photons emitted per second is
`("Given h"=6.63xx10^(-34)Js)`

Options

A. `2xx10^(15)`
B. `3xx10^(15)`
C. `4xx10^(15)`
D. `5xx10^(15)`

Answer

D

Explanation

(d) : Here, `v=6xx10^(14)Hz,h=6.63xx10^(-31)Js`
As `E=hv=6.63xx10^(-34)xx6xx10^(14)=3.98xx10^(-19)J`
`n=(P)/(E)=(2xx10^(-3))/(3.98xx10^(-19))=5xx10^(15)`