The velocity of certain ions that pass undeflected through crossed electric field $E = 7.7\,k\,V /m$ and magnetic field $B = 0.14\,T$ is…..$km/s$

A plane electromagnetic wave travels in vacuum along $z-$ direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is $30 \;MHz$, what is its wavelength in $m$?

The magnetic field of a plane electromagnetic wave is given by

$\overrightarrow{ B }=2 \times 10^{-8} \sin \left(0.5 \times 10^{3} x +1.5 \times 10^{11} t \right) \hat{ j } T$ The amplitude of the electric field would be.

A plane electromagnetic wave of frequency $50\, MHz$ travels in free space along the positive $x-$ direction. At a particular point in space and time, $\vec E = 6.3\,\hat j\,V/m$ . The corresponding magnetic field $\vec B$, at that point will be

A plane electromagnetic wave travels in a medium of relative permeability $1.61$ and relative permittivity $6.44$. If magnitude of magnetic intensity is $4.5 \times 10^{-2} \;Am ^{-1}$ at a point, what will be the approximate magnitude of electric field intensity at that point$?$

(Given : permeability of free space $\mu_{0}=4 \pi \times 10^{-7}\;NA ^{-2}$, speed of light in vacuum $c =3 \times 10^{8} \;ms ^{-1}$ )