A 100 watt bulb emits monochromatic light of wavelength 400 nm. Calculate the number of photons emitted per second by the bulb.

Explanation

Energy failing per aqure metre per second is .Number of quanta falling per metre second xx Energy of one question
`= 6.37 xx 10^(15) xx (hc)/(lambda)`
`= 6.37 xx 10^(12) xx (6.25 xx 10^(-34) xx 3 xx 10^(8))/(632.6 xx 10^(-6))`
`= 2 xx 10^(-3) J m^(-1)s^(-1)`