An alternating voltage of amplitude $40 \, V$ and frequency $4 \, kHz$ is applied directly across a capacitor of $12 \, \mu F$. The maximum displacement current between the plates of the capacitor is nearly: (in $ \, A$)

An insulator plate is passed between the plates of a capacitor. The displacement current

Who produced electromagnetic waves for the first time?

Imagine a world where free magnetic charges exist. In this world,a circuit is made with a $U$-shape wire and a rod free to slide on it. $A$ current carried by free magnetic charges can flow in the circuit. When the circuit is placed in a uniform electric field $E$ perpendicular to the plane of the circuit and the rod is pulled to the right with a constant speed $v$,the magnetic $emf$ in the circuit and the direction of the corresponding current,arising because of changing electric flux will be ($l$ is the length of the rod and $c$ is the speed of light).

Which scientist first time produced electromagnetic waves in laboratory?

$A$ magnetic field can be produced by