The relative permittivity of distilled water is $81$. The velocity of light in it will be $....\times 10^{7} \text{ m/s}$. (Given $\mu_{r} = 1$) (in $.33$)

The electric fields of two plane electromagnetic waves in vacuum are given by $\overrightarrow{E}_{1}=E_{0} \hat{j} \cos (\omega t-kx)$ and $\overrightarrow{E}_{2}=E_{0} \hat{k} \cos (\omega t-ky)$. At $t=0$,a particle of charge $q$ is at the origin with a velocity $\overrightarrow{v}=0.8 c \hat{j}$ ($c$ is the speed of light in vacuum). The instantaneous force experienced by the particle is:

The ratio of the magnitudes of the electric field and $10^8$ times the magnetic field of a plane electromagnetic wave is

$A$ magnetic field vector in an electromagnetic wave is represented by $\vec{B} = B_0 \sin(2\pi vt - \frac{2\pi x}{\lambda}) \hat{j}$. Its associated electric field vector is . . . . . . .

The rms value of the electric field of the light coming from the sun is $720 \ N/C$. The average total energy density of the electromagnetic wave is $:-$

The electric field of a plane electromagnetic wave of wave number $k$ and angular frequency $\omega$ is given by $\vec{E} = E_0(\hat{i} + \hat{j}) \sin(kz - \omega t)$. Which of the following gives the direction of the associated magnetic field $\vec{B}$?