The electromagnetic waves travel in a medium at a speed of $2.0 \times 10^{8}\, m / s$. The relative permeability of the medium is $1.0.$ The relative permittivity of the medium will be

An electromagnetic wave with frequency $\omega $ and wavelength $\lambda $ travels in the $+y$ direction. Its magnetic field is along $+x$ axis. The vector equation for the associated electric field (of amplitude $E_0$) is

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 :-

The electric field associated with an electromagnetic wave propagating in a dielectric medium is given by $\vec{E}=30(2 \hat{x}+\hat{y}) \sin \left[2 \pi\left(5 \times 10^{14} t-\frac{10^7}{3} z\right)\right] \mathrm{V} \mathrm{m}^{-1}$. Which of the following option($s$) is(are) correct?

[Given: The speed of light in vacuum, $c=3 \times 10^8 \mathrm{~ms}^{-1}$ ]

($A$) $B_x=-2 \times 10^{-7} \sin \left[2 \pi\left(5 \times 10^{14} t-\frac{10^7}{3} z\right)\right] \mathrm{Wbm}^{-2}$.

($B$) $B_y=2 \times 10^{-7} \sin \left[2 \pi\left(5 \times 10^{14} t-\frac{10^7}{3} z\right)\right] \mathrm{Wbm}^{-2}$

($C$) The wave is polarized in the $x y$-plane with polarization angle $30^{\circ}$ with respect to the $x$-axis.

($D$) The refractive index of the medium is $2$ .

Ozone layer blocks the radiation of wavelength

The electric field component of an electromagnetic wave in vaccum is given as $\vec E = 3\cos \,\left( {1.8y + 5.4 \times {{10}^8}\,t} \right)\hat i$ Its direction of propagation and wavelength is