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 $W/m^2$.

$A$ laser beam of pulse power $10^{12} \ W$ is focused on an object area of $10^{-4} \ cm^2$. The energy flux in $W/cm^2$ at the point of focus is:

Suppose that the electric field amplitude of an electromagnetic wave is $E_{0} = 120 \; N/C$ and that its frequency is $\nu = 50.0 \; MHz$.
$(a)$ Determine $B_{0}, \omega, k,$ and $\lambda$.
$(b)$ Find expressions for $E$ and $B$.

Energy stored in electromagnetic oscillations is in the form of

$A$ laser beam has an intensity of $4.0 \times 10^{14} \ W/m^{2}$. The amplitude of the magnetic field associated with the beam is . . . . . . $T$. (Take $\epsilon_{0} = 8.85 \times 10^{-12} \ C^{2}/Nm^{2}$ and $c = 3 \times 10^{8} \ m/s$)

The velocity of an electromagnetic wave in a medium is $2.5 \times 10^{8} \ m/s$. What is the dielectric constant of the medium?