Question 365: AC fundamentals

Question

In an oscillating LC circuit, the maximum charge on the capacitor is '$$Q$$'. When the energy is stored equally between the electric and magnetic fields, the charge on the capacitor becomes

Accepted Answer

Maximum energy stored in a capacitor,
$$\mathrm{E}_1=\frac{\mathrm{Q}^2}{2 \mathrm{C}}$$
When energy is stored equally between the electric and magnetic fields, then energy in the capacitor is $$\mathrm{E}_2=\frac{1}{2} \mathrm{E}_1$$
If $$\mathrm{Q}^{\prime}$$ is the charge on the capacitor in this case, then $$\mathrm{E}_2=\frac{\mathrm{Q}^{\prime 2}}{2 \mathrm{C}}$$.
$$\begin{aligned}
	herefore \quad & \frac{\mathrm{Q}^{\prime 2}}{2 \mathrm{C}}=\frac{1}{2} \frac{\mathrm{Q}^2}{2 \mathrm{C}} \
\mathrm{Q}^{\prime} & =\frac{\mathrm{Q}}{\sqrt{2}}.
\end{aligned}$$

Answer

$$\frac{\mathrm{Q}}{4}$$

Answer

$$\mathrm{\frac{Q}{2}}$$

Answer

$$\frac{\mathrm{Q}}{\sqrt{2}}$$

Answer

$$\frac{\mathrm{Q}}{\sqrt{3}}$$

AC fundamentals

In an oscillating LC circuit, the maximum charge on the capacitor is '$Q$'. When the energy is stored equally between the electric and magnetic fields, the charge on the capacitor becomes

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