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If wavelength of photon is $2.2 \times 10^{-11} \mathrm{~m}$ and $h=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}$, then momentum of photon
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The correct answer is:
$3 \times 10^{-23} \mathrm{~kg} \mathrm{~ms}^{-1}$
Given, wavelength of photon, $\lambda=22 \times 10^{-11} \mathrm{~m}$
Plank constant, $h=6.6 \times 10^{-34} \mathrm{Js}$
We know that, $\lambda=\frac{h}{m c} \Rightarrow m c=\frac{h}{\lambda}$ and $m c=$ momentum
$$
\begin{aligned}
\therefore \text { Momentum } & =\frac{6.6 \times 10^{-34}}{2.2 \times 10^{-11}} \\
& =3 \times 10^{-23} \mathrm{~kg} \mathrm{~ms}^{-1}
\end{aligned}
$$
Plank constant, $h=6.6 \times 10^{-34} \mathrm{Js}$
We know that, $\lambda=\frac{h}{m c} \Rightarrow m c=\frac{h}{\lambda}$ and $m c=$ momentum
$$
\begin{aligned}
\therefore \text { Momentum } & =\frac{6.6 \times 10^{-34}}{2.2 \times 10^{-11}} \\
& =3 \times 10^{-23} \mathrm{~kg} \mathrm{~ms}^{-1}
\end{aligned}
$$
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