Write magnitude and dimensional formula of $\frac{1}{{\sqrt {{\mu _0}{ \in _0}} }}$

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?

The magnetic field of a plane electromagnetic wave is given by

$\vec B\, = {B_0}\hat i\,[\cos \,(kz - \omega t)]\, + \,{B_1}\hat j\,\cos \,(kz - \omega t)$ where ${B_0} = 3 \times {10^{-5}}\,T$ and ${B_1} = 2 \times {10^{-6}}\,T$. The rms value of the force experienced by a stationary charge $Q = 10^{-4} \,C$ at $z = 0$ is closet to

A point source of $100\,W$ emits light with $5 \%$ efficiency. At a distance of $5\,m$ from the source, the intensity produced by the electric field component is :

In the given electromagnetic wave $E_y=600 \sin (\omega t-k x) \mathrm{Vm}^{-1}$, intensity of the associated light beam is (in $\mathrm{W} / \mathrm{m}^2$ ); (Given $\epsilon_0=$ $\left.9 \times 10^{-12} \mathrm{C}^{-2} \mathrm{~N}^{-1} \mathrm{~m}^{-2}\right)$

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