$A$ 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 $c = 3 \times 10^{8} \ m/s$)

$A$ point source of electromagnetic radiation has an average power output of $800 \ W$. Find the maximum value of the magnetic field at a distance of $3.5 \ m$ from the source.

Three observers $A, B$ and $C$ measure the speed of light coming from a source. Observer $A$ moves towards the source,observer $C$ moves away from the source with the same speed,and observer $B$ remains stationary. The surrounding space is a vacuum everywhere. Which of the following is true regarding the measured speeds ${v_A}, {v_B}$ and ${v_C}$?

$A$ plane electromagnetic wave is moving in free space with velocity $c = 3 \times 10^8 \ m/s$ and its electric field is given as $\vec{E} = 54 \sin(kz - \omega t) \hat{j} \ V/m$, where $\hat{j}$ is the unit vector along the $y$-axis. The magnetic field vector $\vec{B}$ of the wave 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 $500\, MHz$ is travelling in vacuum along $y$-direction. At a particular point in space and time,$\overrightarrow{B} = 8.0 \times 10^{-8} \hat{z}\, T$. The value of electric field at this point is (speed of light $c = 3 \times 10^{8}\, m/s$). $\hat{x}, \hat{y}, \hat{z}$ are unit vectors along $x, y$ and $z$ directions.