If the direction of propagation of an electromagnetic wave is along the $z$-axis,then the directions of the electric field $(E)$ and magnetic field $(B)$ are:

The electric fields of two plane electromagnetic waves in vacuum are given by $\overrightarrow{E}_{1}=E_{0} \hat{j} \cos (\omega t-kx)$ and $\overrightarrow{E}_{2}=E_{0} \hat{k} \cos (\omega t-ky)$. At $t=0$,a particle of charge $q$ is at the origin with a velocity $\overrightarrow{v}=0.8 c \hat{j}$ ($c$ is the speed of light in vacuum). The instantaneous force experienced by the particle is:

The magnetic field of an electromagnetic wave is given by $B_y = 3 \times 10^{-7} \sin(10^3 x + 3 \times 10^{11} t)$,where $x$ is in meters and $t$ is in seconds. The wavelength of the electromagnetic wave is: (in $cm$)

The speed of an electromagnetic wave in a medium (whose dielectric constant is $2.25$ and relative permeability is $4$) is equal to .......... $\times 10^8 \, m/s$.

$A$ $27\, mW$ laser beam has a cross-sectional area of $10\, mm^2$. The magnitude of the maximum electric field in this electromagnetic wave is given by: $........\, kV/m$. [Given permittivity of free space $\epsilon_0 = 9 \times 10^{-12}\, SI\, units$, speed of light $c = 3 \times 10^8\, m/s$]

The ratio of the speeds of electromagnetic waves in a vacuum and in a medium with dielectric constant $K=3$ and permeability $\mu=2\mu_{0}$ is (where $\mu_{0}$ is the permeability of vacuum).