Question

If energy of the photon is 10 eV, then momentum of the photon isk

• A. $5.33\times {10}^{-25}kgm/s$
• B. $5.33\times {10}^{-27}kgm/s$
• C. $5.33\times {10}^{-29}kgm/s$
• D. $5.33\times {10}^{-23}kgm/s$

Answer 1

The correct option is B $5.33\times {10}^{-27}kgm/s$

$\begin{array}{cc}\text{Energy of Photon}& =10eV\\ & =10\times 1.6\times {10}^{-19}J\end{array}$

$\begin{array}{c}\text{we know that}\\ E=mc\\ \begin{array}{c}E=\text{energy of photon}\\ m=\text{momentum}\\ c=\text{speed of light}=3\times {10}^8{ms}^{-1}\end{array}\end{array}$

$\begin{array}{c}10\times 1.6\times {10}^{-19}=m\times 3\times {10}^8\\ \Rightarrow m=\frac{10\times 1.6\times {10}^{-19}}{3\times {10}^8}\\ m=5.33\times {10}^{-27}{Kgms}^{-1}\end{array}$