Physics 9702 · AS & A Level · Energy stored in a capacitor

Energy stored in a capacitor — practice question

Figure 7.1 shows a capacitor formed from two parallel metal plates with an insulator in between.
(a)[2]

Suggest why, when the capacitor is connected across the terminals of a battery, the capacitor stores energy, not charge.

(b)[2]

Define the capacitance of the capacitor.

(c)[2]

The capacitor is charged so that the potential difference across its plates is $V_0$. It is then connected across a resistor for a short time. It is then disconnected. The energy stored in the capacitor is reduced to $\frac{1}{16}$ of its initial value. Determine, in terms of $V_0$, the potential difference across the capacitor.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: Equal and opposite charges on the plates, so there is no resultant charge

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