In an electromagnetic wave,the maximum value of the electric field is $18 \, V/m$. What is the maximum value of the magnetic field?

An electromagnetic wave travels along the $z$-axis. Which of the following pairs of space and time-varying fields would generate such a wave?

The refractive index of the ionosphere is

$A$ plane $EM$ wave travelling in vacuum along $z$-direction is given by $\vec E = E_0 \sin(kz - \omega t) \hat i$ and $\vec B = B_0 \sin(kz - \omega t) \hat j$.
$(i)$ Evaluate $\int \vec E \cdot d\vec l$ over the rectangular loop $1234$ shown in the figure.
$(ii)$ Evaluate $\int \vec B \cdot d\vec s$ over the surface bounded by loop $1234$.
$(iii)$ Use $\int \vec E \cdot d\vec l = -\frac{d\phi_E}{dt}$ to prove $\frac{E_0}{B_0} = c$.
$(iv)$ By using a similar process and the equation $\int \vec B \cdot d\vec l = \mu_0 I + \mu_0 \epsilon_0 \frac{d\phi_E}{dt}$,prove that $c = \frac{1}{\sqrt{\mu_0 \epsilon_0}}$.

$A$ plane electromagnetic wave travels in free space along the $x$-direction. The electric field component of the wave at a particular point of space and time is $E = 6 \; Vm^{-1}$ along the $y$-direction. Its corresponding magnetic field component, $B$, would be:

An electromagnetic wave of wavelength $2 \times 10^{-10} \,m$ passes from vacuum into a dielectric medium of relative permittivity $4$. Then its wavelength will be