A plane electromagnetic wave is travelling in the positive $X-$axis. At the instant shown electric field at the extremely narrow dashed rectangle is in the $-ve$  $z$ direction and its magnitude is increasing. Which diagram  correctly shows the direction and relative magnitudes of magnetic field at the edges of rectangle :-

All electromagnetic wave is transporting energy in the negative $z$ direction. At a certain point and certain time the direction of electric field of the wave is along positive y direction. What will be the direction of the magnetic field of the wave at that point and instant?

In an electromagnetic wave, the electric and magnetising fields are $100\,V\,{m^{ - 1}}$ and $0.265\,A\,{m^{ - 1}}$. The maximum energy flow is.......$W/{m^2}$

A plane $EM$ wave travelling along $z-$ direction is described$\vec E = {E_0}\,\sin \,(kz - \omega t)\hat i$ and $\vec B = {B_0}\,\sin \,(kz - \omega t)\hat j$. Show that

$(i)$ The average energy density of the wave is given by $U_{av} = \frac{1}{4}{ \in _0}E_0^2 + \frac{1}{4}.\frac{{B_0^2}}{{{\mu _0}}}$

$(ii)$ The time averaged intensity of the wave is given by  $ I_{av}= \frac{1}{2}c{ \in _0}E_0^2$ વડે આપવામાં આવે છે.

The energy associated with electric field is $(U_E)$ and with magnetic field is $(U_B)$ for an electromagnetic wave in free space. Then

A radio transmitter transmits at $830\, kHz$. At a certain distance from the transmitter magnetic field has amplitude $4.82\times10^{-11}\,T$. The electric field and the wavelength are respectively