Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor
Explanation: The displacement current depends on the changing
electric flux across the capacitor plates. Due to the charging of the
capacitor, the charge varies on the capacitor plates with time. Due
to this, the electric flux also varies with time. The relation between
the displacement current and the electric flux is given as
where ϕE is the time varying electric flux through the plane surface,
ϵ0 is the electric permittivity of free space(vacuum) and is equal
to 8.85 × 10-12 C2 N-1 m-2 and Id is the displacement current.
The electric flux is given by Gauss’s law as
The displacement current then becomes
which is dependent on charge. If the charge is zero, then the R.H.S
would be zero so D. is incorrect. If the charge doesn’t change with
time so its derivative w.r.t time will be zero and so will be the
current, so C. is zero. For R.H.S to be non-zero, the charge must vary with time i.e. increase or decrease, hence A. and B. are correct.