A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved further apart by means of insulating handles, then which of the following is not correct?

Question

A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved further apart by means of insulating handles, then which of the following is not correct? (A) The capacitance decreases (B) The charge on the capacitor increases (C) The voltage across the plates increases (D) The electrostatic energy stored in the capacitor increases

Tardigrade Admin · Accepted Answer

As the distance between the plates of capacitor is increased
(i) Capacitance

C

decreases
as

C = \frac{A ε _{0}}{d}

or

C \propto \frac{1}{d}

(ii) Charge on the capacitor remains constant.
(iii) Potential difference increases as

Q = C V

(iv) Electrostatic energy increases
as

U = \frac{1}{2} Q V

and for constant

Q,

U \propto V

Q. A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are moved further apart by means of insulating handles, then which of the following is not correct?

The capacitance decreases

The charge on the capacitor increases

The voltage across the plates increases

The electrostatic energy stored in the capacitor increases

As the distance between the plates of capacitor is increased (i) Capacitance C decreases as C=dAε0​​ or C∝d1​ (ii) Charge on the capacitor remains constant. (iii) Potential difference increases as Q=CV (iv) Electrostatic energy increases as U=21​QV and for constant Q, U∝V