The electric and the magnetic field,associated with an electromagnetic wave propagating along the $+z$-axis,can be represented by

$A$ plane electromagnetic wave of frequency $20\, MHz$ propagates in free space along the $x$-direction. At a particular space and time, $\overrightarrow{E} = 6.6 \hat{j} \, V/m$. What is $\overrightarrow{B}$ at this point?

The rms value of the electric field of an electromagnetic wave emitted by a source is $660 \ NC^{-1}$. The average energy density of the electromagnetic wave is

Which of the following quantities changes when the velocity of light in a vacuum changes?

In the given electromagnetic wave $E_y = 600 \sin (\omega t - kx) \ Vm^{-1}$,the intensity of the associated light beam is (in $W/m^2$); (Given $\epsilon_0 = 9 \times 10^{-12} \ C^2 N^{-1} m^{-2}$ and $c = 3 \times 10^8 \ m/s$)

You are driving in your car listening to music on the radio. Your car is equipped with a radio that can receive radio signals of frequency $(f_1 \approx 3 \, MHz)$,$(f_2 \approx 30 \, MHz)$,and $(f_3 = 3 \, GHz)$. You enter a tunnel with a circular opening of diameter $10 \, m$. Which kind of radio signal will you be able to receive for the longest distance as you continue to travel in the tunnel?