What physical quantity is the same for $X$-rays of wavelength $10^{-10} \; m$,red light of wavelength $6800 \; \mathring{A}$,and radio waves of wavelength $500 \; m$?

$A$ plane electromagnetic wave is propagating along the direction $\frac{\hat{i}+\hat{j}}{\sqrt{2}},$ with its polarization along the direction $\hat{k}$. The correct form of the magnetic field of the wave would be (here $B_{0}$ is an appropriate constant)

The wavelength of an electromagnetic wave radiated by a charge oscillating with a frequency of $1 \, \text{kHz}$ is ..... $km$.

The layer of the atmosphere that reflects low frequency $(LF)$ electromagnetic waves during day time only is

The magnetic field of a plane electromagnetic wave is given by $B = (400 \ \mu T) \sin [ (4.0 \times 10^{15} \ s^{-1}) (t - \frac{x}{c}) ]$. The average energy density corresponding to the electric field is:

The peak value of the magnetic field of an electromagnetic wave moving in a magnetic field is $20 \, nT$. The peak value of the electric field intensity is ..... $V/m$.