The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of 3.3 × 10–3 watt will be
The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of 3.3 × 10–3 watt will be

(h = 6.6 × 10–34 J s)

(1) 1018                               (2) 1017

(3) 1016                               (4) 1015

Solution: Answer (3)

The power of a source is given by the expression: