The speed of an electromagnetic wave in a vacuum depends upon the source of radiation.

An $EM$ wave from air enters a medium. The electric fields are $\overrightarrow {{E_1}} = {E_{01}}\hat x\cos[2\pi v(\frac{z}{c} - t)]$ in air and $\overrightarrow {{E_2}} = {E_{02}}\hat x\cos[k(2z - ct)]$ in medium,where the wave number $k$ and frequency $v$ refer to their values in air. The medium is nonmagnetic. If $\varepsilon_{r_1}$ and $\varepsilon_{r_2}$ refer to relative permittivities of air and medium respectively,which of the following options is correct?

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:

If a source is transmitting electromagnetic waves of frequency $8.196 \times 10^{6} \ Hz$,then the wavelength of the $EM$ waves transmitted from the source will be . . . . . . . (in $cm$)

Electromagnetic theory suggests that light consists of

Write the standard equation for a plane electromagnetic wave traveling in the $x$-direction.