The electric field of a plane electromagnetic wave propagating through a non-magnetic medium is given by $E = 20 \cos (2 \times 10^{10} t - 200 x) \, V/m$. The dielectric constant of the medium is equal to: (Take $\mu_r = 1$)

$A$ plane electromagnetic $(EM)$ wave is propagating along the $x$-direction. It has a wavelength of $4 \text{ mm}$. If the electric field is in the $y$-direction with a maximum magnitude of $60 \text{ Vm}^{-1}$,the equation for the magnetic field is:

In an electromagnetic wave,the amplitude of the electric field is $1 \ V/m$. The frequency of the wave is $5 \times 10^{14} \ Hz$. The wave is propagating along the $z$-axis. The average energy density of the electric field,in $J/m^3$,will be:

If $\vec{E}$ and $\vec{B}$ represent electric and magnetic field vectors of an electromagnetic wave,the direction of propagation of the wave is along

The electric field of a plane polarized electromagnetic wave in free space at time $t = 0$ is given by the expression $\vec E(x,z) = 10\hat j \cos(6x + 8z)$. The magnetic field $\vec B(x,z,t)$ is given by: ($c$ is the velocity of light)

The equation that represents the magnetic field of a plane electromagnetic wave which is propagating along the $x$-direction with a wavelength of $10 \,mm$ and a maximum electric field of $60 \,Vm^{-1}$ in the $y$-direction is (where,$c$ is the speed of light):