How much time will it take for information to propagate over a distance of $30 \, km$ in space?

Select the correct statement from the following:

The electromagnetic waves travel in free space with the velocity of

Suppose that the electric field amplitude of an electromagnetic wave is $E_{0}=120 \text{ NC}^{-1}$ and its frequency $f=50 \text{ MHz}$. Then,which of the following values is incorrectly computed?

An electromagnetic wave of frequency $1 \times 10^{14} \, Hz$ is propagating along the $z$-axis. The amplitude of the electric field is $4 \, V/m$. If $\varepsilon_0 = 8.8 \times 10^{-12} \, C^2/N \cdot m^2$,then the average energy density of the electric field will be:

$A$ radio transmitter transmits at $830 \, kHz$. At a certain distance from the transmitter,the magnetic field has an amplitude of $4.82 \times 10^{-11} \, T$. The electric field and the wavelength are respectively: