Question

There are two source of light, each emitting with a power fo `100W`, One emits `X`-rays of wavelength `1nm` and the other visible light at `5400nm`. Find the ratio of number of photons of `X-rays` to the photos of visible light of the given wavelength?
A. `1//100`
B. `1//200`
C. `1//300`
D. `1//500`

Answer 1

Correct Answer - D
Given,`P=100 W,lambda_(1)=1nm,lambda_(2)=500nm`.If `n_(1)` and `n_(2)` denote the number of photons of `X`-ray and visible of wavelength `lambda_(1)` and `lambda_(2)` respectively. Then
`P=(n_(1)hc)/lambda_(1)=(n_(2)hc)/lambda_(2)` or `n_(1)/lambda_(1)=n_(2)/lambda_(2)` or `n_(1)/n_(2)=lambda_(1)/lambda_(2)=1/500`.