Question

If the energy of a photon is $10 \,eV$, then its momentum is

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

Answer 1

Answer: (D)

Momentum of a photon $\propto \frac{E}{c}=\frac{10 \times 1.6 \times 10^{-19}}{3 \times 10^8}$
$=5.33 \times 10^{-27} kg \,ms ^{-1}$