Physics - Modern Physics Question with Solution | TestHub

Given, power of lamp,$\mathrm{p}=100 \mathrm{W}$

The wavelength of the sodium light,$\lambda =589$$\mathrm{nm} = 589\times {10}^{-9} \mathrm{m}$

Planck constant$h=6.63\times {10}^{-34} \mathrm{J} \mathrm{s}$

Let n photons are delivered per second.

$\therefore$$\text{n}=\frac{\text{Power}}{\text{Energy of each photon}}$(From P = En)

$=\frac{100}{3\text{.}38\times 10^{-19}}=3\times 10^{20}{\text{ photon s}}^{-1}$

$=3\times {10}^{20} \mathrm{photon} {\mathrm{s}}^{-1}$are delivered.