$A$ magnetic field can be produced by

$A$ time-varying potential difference is applied between the plates of a parallel plate capacitor of capacitance $2.5 \mu \text{F}$. The dielectric constant of the medium between the capacitor plates is $1$. It produces an instantaneous displacement current of $0.25 \text{ mA}$ in the intervening space between the capacitor plates. The magnitude of the rate of change of the potential difference will be . . . . . . $\text{V s}^{-1}$.

The source of an electromagnetic wave can be a charge

$A$ parallel plate capacitor is completely immersed in a liquid of resistivity $\rho = 0.25 \, \Omega m$ and relative permittivity $\epsilon_r = 80$. If the plates of the capacitor are connected to an alternating voltage source of $V = V_0 \sin(\omega t)$ at a frequency of $f = 0.4 \, GHz$,then the ratio of the amplitudes of the displacement current $(I_d)$ and conduction current $(I_c)$ is:

Write the meaning of the equation $i = i_c + i_d$.

$A$ 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.