A capacitor made of two parallel plates each of plate area A and separation d, is being charged by an external a.c. source. Show that the displacement current inside the capacitor is the same as the current charging the capacitor. [O.D. I, II, III 2013] OR
A capacitor of capacitance ‘C’ is being charged by connecting it across a dc source along with an ammeter. Will the ammeter show a momentary deflection during the process of charging ? If so, how would you explain this momentary deflection and the resulting continuity of current in the circuit ? Write the expression for the current inside the capacitor. [O.D. I, II, III 2012]
Yes, the ammeter will show a momentary deflection.
The momentary deflection is due to the flow of electrons in the circuit during the charging process. During this process, the electric field between the capacitor plates is changing and hence a displacement current flows in the gap. Hence we can say that there is a continuity of current in the circuit.
Expression
