$A$ 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 electric field intensity of an electromagnetic wave is ....... to the distance it has traveled.

$A$ plane $EM$ wave travelling along $z-$ direction is described by $\vec E = E_0 \sin(kz - \omega t)\hat i$ and $\vec B = B_0 \sin(kz - \omega t)\hat j$. Show that:
$(i)$ The average energy density of the wave is given by $U_{av} = \frac{1}{4} \epsilon_0 E_0^2 + \frac{1}{4} \frac{B_0^2}{\mu_0}$.
$(ii)$ The time-averaged intensity of the wave is given by $I_{av} = \frac{1}{2} c \epsilon_0 E_0^2$.

In an electromagnetic wave,the electric field $\vec{E}$ and the magnetic field $\vec{B}$ oscillate in the region near the source as:

The biological importance of the ozone layer is that:

Light waves are which type of waves?