Question

If h is Plancks constant, the momentum of a photon of wavelength 0.01 $A^o$ is

• A. ${10}^{-2}h$
• B. h
• C. ${10}^2$
• D. ${10}^{12}h$

Answer 1

The correct option is D ${10}^{12}h$

Momentum of photo, $p=\frac{E}{c}=\frac{h\nu }{c}$where E is the energy of a photon and c is the velocity of light.

$\therefore$ $p=\frac{hc}{c\lambda }$ $[\because \nu =\frac{c}{\lambda }]$

$p=\frac{h}{\lambda }=\frac{h}{0.01\times {10}^{-10}}={10}^{12}h$