Two monochromatic beam A and B of equal intensity I, hit a screen. The number of photons hitting the screen by beam A is twice that by beam B. Then what inference can you make about their frequencies?

Options

A. 2
B. 3
C. 4
D. 5

Answer

A

Explanation

Let `n_(1),n_(2)` be the number of photons hitting the screen per second by beam `A` and `B` respectively
Inteisity of beam of photon, `I=nhv`
`thereforen_(1)v_(1)=n_(2)v_(2),n_(1)/n_(2)=v_(2)/v_(1)`
As `n_(1)/n_(2)=2 therefore v_(2)/v_(1)=2,v_(2)=2v_(1)`
i.e., frequency of beam `B` is twice of that of beam `A`.