If a source of power `4 kW` produces `10^(20)` photons`//`second, the radiation belongs to a part of the spectrum called:

Options

A. `gamma` rays
B. X-rays
C. ultaviolet rays
D. microwaves

Answer

B

Explanation

Here,
Power of source, P=4 KW `=4 xx 10^(3)W`
Number of photons emitted per second, `N=10^(20)`
Energy of photon, `E=h upsilon = (hc)/(lambda) = P/N`
or `lambda = (Nhc)/(P) = (10^20 xx 6.63 xx 10 ^(-34) xx 3 xx 10^8)/(4 xx 10^(3))`
`=4.972 xx 10^(-9) m = 49.72 Å`
It lies in the X-ray region