The ratio of average electric energy density and total average energy density of electromagnetic wave is:

In an $EM$ wave propagating along $X-$ direction magnetic field oscillates at a frequency of $3 \times 10^{10}\, Hz$ along $Y-$ direction and has an amplitude of $10^{-7}\, T$. The expression for electric field will be

The electric field of a plane electromagnetic wave propagating along the $x$ direction in vacuum is $\overrightarrow{ E }= E _{0} \hat{ j } \cos (\omega t - kx )$. The magnetic field $\overrightarrow{ B },$ at the moment $t =0$ is :

Electromagnetic waves travel in a medium with speed of $1.5 \times 10^8 \mathrm{~ms}^{-1}$. The relative permeability of the medium is $2.0$ . The relative permittivity will be :

A wave is propagating in a medium of electric dielectric constant $2$ and relative magnetic permeability $50$. The wave impedance of such a medium is.....$ \Omega$

An electric charge $+ q$ moves with velocity $\overrightarrow V  = 3\hat i + 4\hat j + \hat k$ in an electromagnetic field given by :  $\overrightarrow E  = 3\hat i + \hat j + 2\hat k$ and $\overrightarrow B  = \hat i + \hat j - 3\hat k$. The $y-$ component of the force experienced by $+ q$ is :-