Question

A capacitor acts as an infinite resistance for
A) DC
B) AC
C) DC as well as AC
D) Neither AC nor DC

Answer 1

Hint:A capacitor is a device which stores electrical energy in its electrical field. When it is connected in a circuit, it charges itself and thus allows the flow of current throughout the circuit. Due to AC the capacitor charges and discharges. The space between the plates of the capacitor is filled with air or any other insulator. A fully charged capacitor acts as an open circuit.

Complete step by step answer:We know that a capacitor is a device which stores electrical energy in its electrical field. This storage takes place by storing electrical charges on its plates. When the capacitor is connected in a circuit, charges from the positive terminal of the plate get deposited to the negative terminal of the plate and thus there is flow of current in the circuit.

In case of DC, the capacitor is fully charged thus the potential difference across it becomes equal to the voltage of the source. As a result, the capacitor now acts as an open circuit and thus, there is no more flow of charge in this circuit. In other words, we can say that a fully charged capacitor acts as an infinite resistance for DC.

Therefore, option (A) DC is the correct option.

Note:A capacitor connected to an AC source is charged and discharged due to this the capacitor is never fully charged and there is flow of current throughout the circuit. In a DC circuit, a capacitor acts as a closed circuit and once it is fully charged, it acts as an open circuit. In AC circuits, the capacitor keeps on charging and discharging.