An electromagnetic wave of frequency $3 \, GHz$ enters a dielectric medium of relative electric permittivity $2.25$ from vacuum. The wavelength of this wave in that medium will be $....... \times 10^{-2} \, cm$.

$A$ flood light is covered with a filter that transmits red light. The electric field of the emerging beam is represented by a sinusoidal plane wave
$E_x=36\,\sin\,(1.20 \times 10^7z -3.6 \times 10^{15}\,t)\,V/m$
The average intensity of the beam will be.....$W/m^2$

If an electromagnetic wave is propagating in the $x$-direction and the magnetic field $\vec{B}$ at any instant is in the $z$-direction,then at that instant,the electric field $\vec{E}$ will be in the ........ direction.

In an electromagnetic wave,the electric field intensity is $100 \ Vm^{-1}$ and the magnetic intensity is $H_0 = 0.265 \ Am^{-1}$. The maximum intensity of radiation is ..... $Wm^{-2}$.

$A$ sky wave with a frequency $55 \, MHz$ is incident on the $D$-region of the Earth's atmosphere at $45^\circ$. The angle of refraction is ......... $^\circ$ (electron density for the $D$-region is $400 \, \text{electrons}/cm^3$).

The magnetic field in a plane electromagnetic wave is given as $B = (3 \times 10^{-7} \text{ T}) \sin (3 \times 10^4 x + 9 \times 10^{12} t) \hat{j}$. The electric field of this wave is given as: