The amplitude of the electric field associated with a light beam of intensity $\frac{15}{\pi} \text{ W m}^{-2}$ is (in $\text{ N C}^{-1}$)

The electric field of a plane electromagnetic wave, travelling in an unknown non-magnetic medium is given by, $E_y = 20 \sin(3 \times 10^6 x - 4.5 \times 10^{14} t) \text{ V/m}$ (where $x, t$ and other values are in $S$.$I$. units). The dielectric constant of the medium is . . . . . . . (Speed of light in free space is $c = 3 \times 10^8 \text{ m/s}$)

$A$ 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

$A$ plane electromagnetic wave of intensity $6 \, W/m^2$ strikes a small mirror of area $30 \, cm^2$,held perpendicular to the approaching wave. The momentum transmitted in $kg \cdot m/s$ by the wave to the mirror each second will be:

$A$ plane electromagnetic wave of frequency $20 \text{ MHz}$ travels through space along the $x$-direction. If the electric field vector at a certain point in space is $6 \text{ V m}^{-1}$,what is the magnetic field vector at that point?

Why does a microwave oven heat up a food item containing water molecules most efficiently?