Question

The mass of photon having wavelength $1nm$ is:

• A. $2.21\times {10}^{-35}kg$
• B. $2.21\times {10}^{-33}g$
• C. $2.21\times {10}^{-33}kg$
• D. $2.21\times {10}^{-26}kg$

Answer 1

Answer: (C)

$2.21\times {10}^{-33}kg$

Photons travel with the speed of light = $3\times {10}^{8}m/s$

De Broglie wavelength $\lambda =\frac{h}{mv}$

$h=6.626\times {10}^{-34}Js$

Now, $1\times {10}^{-9}=\frac{6.626\times {10}^{-34}}{m\times 3\times {10}^8}$

$m=2.21\times {10}^{-33}kg$

The mass of photon having wavelength 1nm is $2.21\times {10}^{-33}kg$