Question

A photon of wavelength $1\mathring{\text{A}}$ is completely absorbed by a surface. What is the momentum transferred by this photon?

• A. ${10}^{-34}\text{Ns}$
• B. $6.63\times {10}^{-24}\text{Ns}$
• C. $3.31\times {10}^{-24}\text{Ns}$
• D. $10.52\times {10}^{-24}\text{Ns}$

Answer 1

The correct option is B $6.63\times {10}^{-24}\text{Ns}$

As all of the momentum of the photon is transferred to the surface by absorption
$\Rightarrow \Delta P=\frac{h}{\lambda }$
$\therefore \Delta P=\frac{6.63\times {10}^{-34}}{{10}^{-10}}=6.63\times {10}^{-24}\text{Ns}$

Hence, $\left(B\right)$ is the correct answer.

Why this question? A typical formula based numericals can be asked in NEET exam.