Question

If a source of power `4 kW` produces `10^(20)` photons`//`second, the radiation belongs to a part of the spectrum called:
A. X-rays have wavelength of the order of the inter-atomic spacing
B. ultraviolet rays
C. microwaves
D. `gamma`-rays

Answer 1

Correct Answer - B
Energy of each photon `(4000)/(10^(20))=4xx10^(17)`
`lambda=(12400xx1.6xx10^(-19))/(4xx10^(-17))A^(0)=49.6+B240Å`
It is in ultraviolet spectrum.