In an $EM$ wave,the amplitude of the magnetic field $H_0$ and the amplitude of the electric field $E_0$ at any place are related as:

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?

$A$ plane electromagnetic wave of frequency $50 \ MHz$ travels in free space. If the average energy densities in the electric field and magnetic field are $K_{E}$ and $K_{B}$ respectively,then the correct option in the following is

What is the amplitude of the electric field in a parallel beam of light of intensity $\left(\frac{15}{\pi}\right) \text{ W/m}^2$ (in $\text{ N/C}$)? $\left[\text{Assume} \frac{1}{4 \pi \varepsilon_0} = 9 \times 10^9 \text{ Nm}^2/\text{C}^2\right]$

$A$ source emits electromagnetic waves of frequency $8.2 \times 10^6 \text{ Hz}$. What is the wavelength of these waves in meters?

What is the wavelength of light with a frequency of $100\;Hz$?