To establish an instantaneous displacement current of $2\,A$ in the space between two parallel plates of a $1\,\mu F$ capacitor,the potential difference across the capacitor plates will have to be changed at the rate of:

$A$ capacitor of capacitance $C$ is connected across an $AC$ source of voltage $V$,given by $V = V_{0} \sin \omega t$. The displacement current between the plates of the capacitor would then be given by:

According to Maxwell's hypothesis,a changing electric field gives rise to

$A$ parallel-plate capacitor with circular plates is being discharged. The radius of the circular plates is $10 \ cm$. $A$ circular loop of radius $20 \ cm$ is concentric with the capacitor and located halfway between the plates. If the electric field between the plates is changing at the rate of $3.6 \times 10^{12} \ V/(m \cdot s)$,then the displacement current through the loop is (Assume $\frac{1}{4 \pi \varepsilon_0} = 9 \times 10^9 \ N \cdot m^2/C^2$) (in $A$)

The source of a time-varying magnetic field may be:
$(A)$ A permanent magnet
$(B)$ An electric field changing linearly with time
$(C)$ Direct current
$(D)$ A decelerating charged particle
$(E)$ An antenna fed with a digital signal
Choose the correct answer from the options given below:

What was the primary difficulty in establishing the wave theory of light,and who explained it?