In a plane electromagnetic wave,the electric field oscillates sinusoidally at a frequency of $2 \times 10^{10} \, Hz$ and an amplitude of $48 \, V/m$. What is the wavelength of the wave in $cm$?

The relationship between the amplitude of the electric field $(E_0)$ and the magnetic field $(B_0)$ in an electromagnetic wave is given by:

$A$ laser beam has intensity $17.7 \times 10^{14} \ W/m^2$. The amplitude of the electric field is
[Use $\epsilon_0 = 8.85 \times 10^{-12} \ C^2 / (N \cdot m^2)$]

$A$ flood light is covered with a filter that transmits red light. The electric field of the emerging beam is represented by a sinusoidal plane wave
$E_x=36\,\sin\,(1.20 \times 10^7z -3.6 \times 10^{15}\,t)\,V/m$
The average intensity of the beam will be.....$W/m^2$

If ${\varepsilon _0}$ and ${\mu _0}$ are respectively the electric permittivity and the magnetic permeability of free space,and ${\varepsilon}$ and ${\mu}$ are the corresponding quantities in a medium,the refractive index of the medium is:

For the plane electromagnetic wave given by $E=E_0 \sin (\omega t-kx)$ and $B=B_0 \sin (\omega t-kx)$,the ratio of average electric energy density to average magnetic energy density is