The electromagnetic waves travel with a velocity

The magnetic field of a beam emerging from a filter facing a floodlight is given by B${B_0} = 12 \times {10^{ – 8}}\,\sin \,(1.20 \times {10^7}\,z – 3.60 \times {10^{15}}t)T$. What is the average intensity of the beam ?

Aplane electromagnetic wave is incident on a plane surface of area A normally, and is perfectly reflected. If energy $E$ strikes the surface in time $t$ then average pressure exerted on the surface is ( $c=$ speed of light)

The magnetic field of an electromagnetic wave is given by

$\vec B = 1.6 \times {10^{ – 6}}\,\cos \,\left( {2 \times {{10}^7}z + 6 \times {{10}^{15}}t} \right)\left( {2\hat i + \hat j} \right)\frac{{Wb}}{{{m^2}}}$ The associated electric field will be

The magnetic field vector of an electromagnetic wave is given by ${B}={B}_{o} \frac{\hat{{i}}+\hat{{j}}}{\sqrt{2}} \cos ({kz}-\omega {t})$; where $\hat{i}, \hat{j}$ represents unit vector along ${x}$ and ${y}$-axis respectively. At $t=0\, {s}$, two electric charges $q_{1}$ of $4\, \pi$ coulomb and ${q}_{2}$ of $2 \,\pi$ coulomb located at $\left(0,0, \frac{\pi}{{k}}\right)$ and $\left(0,0, \frac{3 \pi}{{k}}\right)$, respectively, have the same velocity of $0.5 \,{c} \hat{{i}}$, (where ${c}$ is the velocity of light). The ratio of the force acting on charge ${q}_{1}$ to ${q}_{2}$ is :-