There are two sources of light, each emitting with a power of 100 W. One emits X-rays of wavelength 1 nm and the other visible light at 500 nm. Find the ratio of number of photons of X-rays to the photons of visible light of the given wavelength?

Hint: The energy of photons depends on the wavelength of the rays.

Step 1: Find the ratio of photons.

Suppose the wavelength of X-rays is λ1, and the wavelength of visible light is λ2.

                             Given,  P=100W            λ1=1nmand       λ2=500 nm

Also, n1 and n2 represents the number of photons of X-rays and visible light emitted from the two sources per sec.

So, Et=P=n1hcλ1=n2hcλ2 n1λ1=n2λ2 n1n2=λ1λ2=1500