For which of the following media will the wave propagation occur without experiencing attenuation?

In an electromagnetic wave,the maximum value of the electric field is $18 \, V/m$. What is the maximum value of the magnetic field?

The equation of a light wave,normally incident on a surface,is given by $B = (100 \text{ nT}) \sin(2\pi(10^{15}t - (3 \times 10^{-7})x) + \frac{\pi}{6})$. Find the intensity of light on that surface in $W/m^2$.

Electromagnetic waves travel in a medium which has relative permeability $1.3$ and relative permittivity $2.14$. Then the speed of the electromagnetic wave in the medium will be

$A$ beam of light travelling along the $X$-axis is described by the electric field $E_{y} = 900 \sin \omega(t - x/c)$. The ratio of the electric force to the magnetic force on a charge $q$ moving along the $Y$-axis with a speed of $3 \times 10^{7} \, m/s$ will be:
[Given: speed of light $c = 3 \times 10^{8} \, m/s$]

Write the equation for the energy density of electromagnetic waves.