Suppose that the intensity of a laser is $\left(\frac{315}{\pi}\right) \ W/m^2$. The $rms$ electric field,in units of $V/m$,associated with this source is close to the nearest integer. Given: $\epsilon_0 = 8.86 \times 10^{-12} \ C^2 N^{-1} m^{-2}$ and $c = 3 \times 10^8 \ m/s$.

If the magnetic field of a plane electromagnetic wave is given by $B = 5 \times 10^{-6} \sin (0.6 \times 10^2 x + 0.5 \times 10^{10} t)$,then the speed of the wave is

An electromagnetic wave travelling in $x$-direction is described by field equation $E_y = 300 \sin \omega \left( t - \frac{x}{c} \right)$. If the electron is restricted to move in $y$-direction only with speed of $1.5 \times 10^6 \text{ m/s}$, then the ratio of maximum electric and magnetic forces acting on the electron is . . . . . . .

$A$ plane electromagnetic wave travels in a medium of relative permeability $\mu_{r} = 1.61$ and relative permittivity $\epsilon_{r} = 6.44$. If the magnitude of the magnetic intensity $H$ is $4.5 \times 10^{-2} \; A m^{-1}$ at a point,what will be the approximate magnitude of the electric field intensity $E$ at that point? (Given: $\mu_{0} = 4 \pi \times 10^{-7} \; N A^{-2}$,$c = 3 \times 10^{8} \; m s^{-1}$)

What is the displacement variable in a simple pendulum and the propagation of light?

$A$ charged particle oscillates about its mean equilibrium position with a frequency of $10^{9} \,Hz$. The frequency of electromagnetic waves produced by the oscillator is . . . . . . .