Electric field associated with an em wave in vacuum is given by vec{E}=hat{i} 40 cos left(k z-6 × 1

English

Gujarati

Hindi

8.Electromagnetic waves

medium

The electric field associated with an em wave in vacuum is given by $\vec{E}=\hat{i} 40 \cos \left(k z-6 \times 10^{8} t\right)$ where $E, x$ and $t$ are in $volt/m,$ meter and seconds respectively. The value of wave vector $k$ is....$ m^{-1}$

A

$2$

B

$0.5$

C

$6 $

D

$3 $

(AIPMT-2012)

Solution

Compare the given equation with

$E=E_{0} \cos (k z-\omega t)$

we get, $\omega=6 \times 10^{8} \mathrm{s}^{-1}$

Wave vector, $k=\frac{\omega}{c}=\frac{6 \times 10^{8}\, \mathrm{s}^{-1}}{3 \times 10^{8} \,\mathrm{ms}^{-1}}=2\, \mathrm{m}^{-1}$

Standard 12

Physics

Share

Similar Questions

The magnetic field of a plane electromagnetic Wave is $\overrightarrow{ B }=3 \times 10^{-8} \sin [200 \pi( y + ct )] \hat{ i }\, T$ Where $c=3 \times 10^{8} \,ms ^{-1}$ is the speed of light. The corresponding electric field is

hard

(JEE MAIN-2020)

Suppose that the electric field amplitude of an electromagnetic wave is $E_{0}=120\; N / C$ and that its frequency is $v=50.0\; MHz$.

$(a)$ Determine, $B_{0}, \omega, k,$ and $\lambda .$

$(b)$ Find expressions for $E$ and $B$

medium

Aplane electromagnetic wave is incident on a plane surface of area A normally, and is perfectly reflected. If energy $E$ strikes the surface in time $t$ then average pressure exerted on the surface is ( $c=$ speed of light)

easy

The electric field part of an electromagnetic wave in a medium is represented by

$E_x=0, E_y=2.5 \frac{N}{C}\, cos\,\left[ {\left( {2\pi \;\times\;{{10}^6}\;\frac{{rad}}{s}\;\;} \right)t – \left( {\pi \;\times\;{{10}^{ – 2}}\;\frac{{rad}}{m}} \right)x} \right]$,and $ E_z=0$ . The wave is

medium

(AIPMT-2009)

An electromagnetic wave of frequency $\nu = 3.0\,MHz$ passes from vacuum into a dielectric medium with permitivity $\varepsilon = 4.0$. Then

easy

(AIEEE-2004)