Who produced electromagnetic waves for the first time?

The potential difference between the two plates of a parallel plate capacitor changes at a rate of $10^6 \; V/s$. If the capacitance of the capacitor is $2 \; \mu F$, what is the displacement current in the dielectric of the capacitor?

The source of an electromagnetic wave can be a charge

Derive the expression for the displacement current term in the modified Ampere's circuital law. Define displacement current and state its $SI$ unit.

$A$ parallel plate capacitor (Figure) made of circular plates each of radius $R=6.0\; cm$ has a capacitance $C=100\; pF$. The capacitor is connected to a $230\; V$ ac supply with a (angular) frequency of $300 \;rad \;s ^{-1}$.
$(a)$ What is the rms value of the conduction current?
$(b)$ Is the conduction current equal to the displacement current?
$(c)$ Determine the amplitude of $B$ at a point $3.0\; cm$ from the axis between the plates.

An infinitely long thin wire carrying a uniform linear static charge density $\lambda$ is placed along the $z-$axis. The wire is set into motion along its length with a uniform velocity $\vec{V} = v\hat{k}$. Calculate the Poynting vector $\vec{S} = \frac{1}{\mu_0}(\vec{E} \times \vec{B})$.