Physics 9702 · AS & A Level · Energy stored in a capacitor
Energy stored in a capacitor — practice question
As shown in Fig. 6.1, an uncharged capacitor is arranged in series with a battery, a switch and a resistor. The battery has an e.m.f. $9.0\,\text{V}$ and negligible internal resistance. The capacitor has capacitance $4700\,\mu\text{F}$. The switch is closed at $t = 0$. From $t = 0$ to $t = 4.0\,\text{s}$, a charge of $22\,\text{mC}$ passes through the resistor.
(a(i))[2]
Calculate the energy transfer in the battery over the interval $t = 0$ to $t = 4.0\,\text{s}$.
(a(ii)-1)[2]
Determine the potential difference $V$ across the capacitor at time $t = 4.0\,\text{s}$.
(a(ii)-2)[2]
Determine the energy stored in the capacitor at time $t = 4.0\,\text{s}$.
(b)[1]
Suggest why the answers in (a)(i) and (a)(ii) part 2 are not the same.
(a(ii) part 2)[2]
Calculate the energy stored in the capacitor.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applies $E = EQ$” …