Question

The momentum of a photon in an X-ray beam of ${10}^{-10}$ metre wavelength is

• A. $1.5\times {10}^{-23}kg-m/sec$
• B. $6.6\times {10}^{-24}kg-m/sec$
• C. $6.6\times {10}^{-44}kg-m/sec$
• D. $2.2\times {10}^{-52}kg-m/sec$

Answer 1

The correct option is B

$6.6\times {10}^{-24}kg-m/sec$

Momentum of photon
$p=\frac{h}{\lambda }=\frac{6.6\times {10}^{-34}}{{10}^{-10}}=6.6\times {10}^{-24}kg-m/sec$.