Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Medical
  • A 27 mW laser beam has a cross-sectional area of . The mag

A 27 mW laser beam has a cross-sectional area of \mathrm{10 \mathrm{~mm}^2}. The magnitude of the maximum electric field in this electromagnetic wave is given by [Given permittivity of space \mathrm{\varepsilon_0=9 \times 10^{-12}} SI units, speed of light \mathrm{c=3 \times 10^8 \mathrm{~m} / \mathrm{s}} ]

Option: 1

2 kV/m
 


Option: 2

0.7 kV/m


Option: 3

1 kV/m


Option: 4

1.4 kV/m


Answers (1)

best_answer

The intensity of the electromagnetic wave is given by

\mathrm{\mathrm{I}=\operatorname{Power}(\mathrm{P}) / \operatorname{Area}(\mathrm{A})=1 / 2 \varepsilon_0 \mathrm{E}^2 \mathrm{C}}

\begin{aligned} & \text{E}=\sqrt{\frac{2 P}{A \epsilon_0 C}}=\sqrt{\frac{2 \times 27 \times 10^{-3}}{10 \times 10^{-6} \times 9 \times 10^{-12} \times 3 \times 10^8}} \\ \\& \text{E}=\sqrt{0.2 \times 10^7}=\sqrt{2 \times 10^6} \end{aligned}

\mathrm{\mathrm{E}=1.4 \mathrm{kV} / \mathrm{m}}

Posted by

admin

View full answer

NEET 2024 Most scoring concepts

    Just Study 32% of the NEET syllabus and Score up to 100% marks

Similar Questions

Trending Articles/News

anam-khan

Before NEET, CMC Vellore’s unique MBBS admissions tested aptitude along with merit; paper-leak restarts debate
anam-khan

NEET-UG paper leak fallout: Latur admin orders crackdown on illegal coaching classes
anam-khan

Re-NEET in 30 days a ‘massive logistical challenge’, NTA adopts ‘zero trust’ policy: Report

Latest Question