In an experiment, a bulb of power 1000 W produces 1010 photons/second. The radiation belongs to a part of the spectrum called
| A : | γ-rays | |
| B : | X-rays | |
| C : | ultraviolet rays | |
| D : | microwaves |
If N is the number of photons emitted by the source per second,then the power P transmitted in the beam equals N times the energy per photon E, so that
P = N E.
or, E = P/N
we have, P = 1000W
N = 1010
so, E = 1000/1010
= 10-7J
now E = hν
or, ν = E/h (h is the plank's constant = 6.63 x 10-34Js)
= 10-7/6.63 x 10-34
= 1.5 x 1028Hz
The above frequency corresponds to the γ - rays region, hence option A is correct.