When light propagates through a material medium of relative permittivity $\varepsilon_{ r }$ and relative permeability $\mu_{r^{\prime}}$ the velocity of light, $v$ is given by: (c - velocity of light in vacuum)

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

The electric field associated with an em wave in vacuum is given by $\vec{E}=\hat{i} 40 \cos \left(k z-6 \times 10^{8} t\right)$ where $E, x$ and $t$ are in $volt/m,$ meter and seconds respectively. The value of wave vector $k$ is....$ m^{-1}$

The electric field of plane electromagnetic wave of amplitude $2\,V/m$ varies with time, propagating along $z-$ axis. The average energy density of magnetic field (in $J/m^3$ ) is

If $\overrightarrow E $ and $\overrightarrow B $ are the electric and magnetic field vectors of E.M. waves then the direction of propagation of E.M. wave is along the direction of

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 :-