The refractive index of the ionosphere is ........

The ratio of the amplitude of the magnetic field to the amplitude of the electric field for an electromagnetic wave propagating in vacuum is equal to:

$A$ plane electromagnetic wave of frequency $28 \, MHz$ travels in free space along the positive $x$-direction. At a particular point in space and time, the electric field is $9.3 \, V/m$ along the positive $y$-direction. The magnetic field (in $T$) at that point is:

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:

The ratio of the electric field $(E)$ to the magnetic field $(B)$ in an electromagnetic wave gives which physical quantity?

In an electromagnetic wave,the amplitude of the electric field is $1 \ V/m$. The frequency of the wave is $5 \times 10^{14} \ Hz$. The wave is propagating along the $z$-axis. The average energy density of the electric field,in $J/m^3$,will be: