The momentum of a photon associated with a radiation of frequency \( 2 \times 10^{13}\,\mathrm{Hz} \) is (Given: \( h = 6.6 \times 10^{-34}\,\mathrm{J\,s} \) and \( c = 3 \times 10^{8}\,\mathrm{m/s} \))
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 4.4 \times 10^{-29}\,\mathrm{kg\,m/s} \)
A photon of frequency \( \nu \) has energy \( E = h\nu \) and momentum \( p = E/c = h/\lambda \).
\( \displaystyle p = \frac{h\nu}{c} = \frac{6.6\times10^{-34} \times 2\times10^{13}}{3\times10^{8}} \)
\( \displaystyle p = \frac{13.2\times10^{-21}}{3\times10^{8}} = 4.4\times10^{-29}\,\mathrm{kg\,m\,s^{-1}} \)