Who produced electromagnetic waves for the first time?

To establish an instantaneous displacement current of $I$ ampere in the space between the plates of a parallel plate capacitor of $\frac{1}{2} \text{ F}$,the value of $\frac{dV}{dt}$ is .......

$A$ cylindrical region contains a uniform electric field that is along the cylinder axis and is changing with time. If $r$ is the distance from the cylinder axis,the magnitude of the magnetic field within the region is:

$A$ parallel plate capacitor made of circular plates is being charged such that the surface charge density on its plates is increasing at a constant rate with time. The magnetic field arising due to displacement current is

$A$ magnetic field can be produced by

Electromagnetic waves are produced by