In an electromagnetic wave,$E = 50 \sin(\omega t - kx)$. If $\mu = 4\mu_0$ and $\varepsilon = \varepsilon_0$,then the average power per unit area is $-$ (in $W/m^2$)

The electric field of an electromagnetic wave in free space is represented as $\vec{E} = E_0 \cos(\omega t - kz) \hat{i}$. The corresponding magnetic induction vector will be:

$A$ plane electromagnetic wave of frequency $100 \, MHz$ is travelling in vacuum along the $x$-direction. At a particular point in space and time,$\overrightarrow{B} = 2.0 \times 10^{-8} \hat{k} \, T$ (where $\hat{k}$ is the unit vector along the $z$-direction). What is $\overrightarrow{E}$ at this point?

Light is an electromagnetic wave. Its speed in vacuum is given by the expression

What are called non-mechanical waves? Give its examples.

$A$ sky wave with a frequency $55 \, MHz$ is incident on the $D$-region of the Earth's atmosphere at $45^\circ$. The angle of refraction is ......... $^\circ$ (electron density for the $D$-region is $400 \, \text{electrons}/cm^3$).