Ampere-Maxwell law explains the flow of
current through a capacitor when it being
charged by a battery, using the concept of
displacement current. According to Ampere-
maxwell law, the line integral of magnetic field
over a closed loop is `mu_0` times the sum of
conduction current (I) and displacement current
`(I_D)`. Displacement current `I_D` arises due to change
in magnetic flux in between the two plates of
capacitor which was not considered by Ampere.
Expression for displacement current is
`I_D=in_0 (dphi_E)/(dt)`
