Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • A photon of wavelength is incident on a totally reflecting su

A photon of wavelength 5030 \mathrm{~A}^{\circ} is incident on a totally reflecting surface. The momentum delivered by the photon is equal to

Option: 1

6.63 \times 10^{-27} \mathrm{kgm} / \mathrm{s}


Option: 2

2 \times 10^{-27} \mathrm{kgm} / \mathrm{s}


Option: 3

10^{-27} \mathrm{kgm} / \mathrm{s}


Option: 4

None \, \, of \, \, these


Answers (1)

best_answer

The momentum of the incident radiation is given as  \mathrm{P}=\frac{\mathrm{h}}{\lambda}

When the light is totally reflected normal to the surface the direction
of the ray is reversed. That means it reverses the direction of its
momentum without changing its magnitude.

\Rightarrow \quad Change in momentum has a magnitude 

\Delta \mathrm{P}=2 \mathrm{P}=\frac{2 \mathrm{~h}}{\lambda}

\Rightarrow \quad \Delta \mathrm{P}=\frac{2\left(6.63 \times 10^{-34} \mathrm{~J}-\mathrm{sec}\right)}{\left(6630 \times 10^{-10} \mathrm{~m}\right)}

\Rightarrow \quad \Delta \mathrm{P}=2 \times 10^{-27} \mathrm{kgm} / \mathrm{s}

 

Posted by

Pankaj Sanodiya

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2026: JCECEB invites fresh applications for Jharkhand state merit list correction

Latest Question