An em wave is propagating in a medium with a velocity vec v =vhat{i}. instantaneous oscillating

English

Gujarati

Hindi

8.Electromagnetic waves

easy

An em wave is propagating in a medium with a velocity $\vec v =v\hat i.$ The instantaneous oscillating electric field of this em wave is along $+y$ axis. Then the direction of oscillating magnetic field of the em wave will be along

A

$- z$ direction

B

$+ z $ direction

C

$- x$ direction

D

$- y$ direction

(NEET-2018)

Solution

Velocity of em wave in a medium is given by $\vec{v}=\vec{E} \times \vec{B}$

$\therefore \quad v \hat{i}=(E \hat{j}) \times(\vec{B})$

$[\because \vec{E}=E \hat{j}(\text { Given })]$

As $\hat{i}=\hat{j} \times \hat{k}$ so $\vec{B}=B \hat{k}$

Direction of oscillating magnetic field of the em wave will be along $+z$ direction.

Standard 12

Physics

Share

Similar Questions

The amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is $B_0 = 510 \;nT$.What is the amplitude of the electric field (in $N/C$) part of the wave?

medium

A mathematical representation of electromagnetic wave is given by the two equations $E = E_{max}\,\, cos (kx -\omega\,t)$ and $B = B_{max} cos\, (kx -\omega\,t),$ where $E_{max}$ is the amplitude of the electric field and $B_{max}$ is the amplitude of the magnetic field. What is the intensity in terms of $E_{max}$ and universal constants $μ_0, \in_0.$

medium

Show that average value of radiant flux density $'S'$ over a single period $'T'$ is given by $S = \frac{1}{{2c{\mu _0}}}E_0^2$.

medium

The photon energy in units of $eV$ for electromagnetic wave of wavelength $2\,cm$ is

easy

The electric field component of an electromagnetic wave in vaccum is given as $\vec E = 3\cos \,\left( {1.8y + 5.4 \times {{10}^8}\,t} \right)\hat i$ Its direction of propagation and wavelength is

easy