A plane electromagnetic wave of angular frequency $\omega$ propagates in a poorly conducting medium of conductivity $\sigma$ and relative permittivity $\varepsilon$. Find the ratio of conduction current density and displacement current density in the medium.
$\frac{\varepsilon \varepsilon_0 \omega}{\sigma}$
$\frac{\sigma}{\varepsilon \varepsilon_0 \omega}$
$\frac{\omega}{\sigma \varepsilon \varepsilon_0 }$
$\frac{\omega \sigma}{ \varepsilon \varepsilon_0 }$
A plane electromagnetic wave propagating in the direction of the unit vector $\hat{ n }$ with a speed $c$ is described by electric and magnetic field vectors $E$ and $B$, respectively. Which of the following relations (in $SI$ units) between $E$ and $B$ can be ruled out on dimensional grounds alone?
In an $EM$ wave propagating along $X-$ direction magnetic field oscillates at a frequency of $3 \times 10^{10}\, Hz$ along $Y-$ direction and has an amplitude of $10^{-7}\, T$. The expression for electric field will be
Sun light falls normally on a surface of area $36\,cm ^{2}$ and exerts an average force of $7.2 \times 10^{-9}\,N$ within a time period of $20$ minutes. Considering a case of complete absorption, the energy flux of incident light is.
Write magnitude and dimensional formula of $\frac{1}{{\sqrt {{\mu _0}{ \in _0}} }}$
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