Question

a 50 watt bulb emits monochromatic light of wavelength of 500 angstrom calculate the rate of emission of quanta per second

Answer 1

Answer:

The energy of one photon is

E=λhc​

    =0.57×10−66.626×10−34Js×3×108m/s​

    =3.487×10−19J .

25 watt corresponds to 25 J per second.

The number of photons emitted per second is 3.487×10−1925​=7.17×1019/s.