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title: "An ideal LC circuit consists of a capacitor of capacitance \\(C\\) and an inductor of inductance \\(L\\) with negligible resistance. The capacitor is initially charged to a maximum charge \\(Q_0\\) and then connected across the inductor. Which of the following statements correctly compares the maximum energy stored in the magnetic field of the inductor, \\(U_{B,\\text{max}}\\), to the maximum energy stored in the electric field of the capacitor, \\(U_{E,\\text{max}}\\), and provides a correct physical justification?"
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url: "https://nerd-notes.com/ubq/118641/"
date_modified: "2026-08-04T08:13:25+00:00"
---

# An ideal LC circuit consists of a capacitor of capacitance \(C\) and an inductor of inductance \(L\) with negligible resistance. The capacitor is initially charged to a maximum charge \(Q_0\) and then connected across the inductor. Which of the following statements correctly compares the maximum energy stored in the magnetic field of the inductor, \(U_{B,\text{max}}\), to the maximum energy stored in the electric field of the capacitor, \(U_{E,\text{max}}\), and provides a correct physical justification?

An ideal LC circuit consists of a capacitor of capacitance \(C\) and an inductor of inductance \(L\) with negligible resistance. The capacitor is initially charged to a maximum charge \(Q_0\) and then connected across the inductor. Which of the following statements correctly compares the maximum energy stored in the magnetic field of the inductor, \(U_{B,\text{max}}\), to the maximum energy stored in the electric field of the capacitor, \(U_{E,\text{max}}\), and provides a correct physical justification?

![A schematic circuit diagram showing a single rectangular loop. On the left vertical wire, a parallel-plate capacitor is labeled C. On the right vertical wire, an inductor coil is labeled L. At the top horizontal wire, an open switch S is shown. No other components or labels appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785831205-bcgXuW.jpg)

- **A.** \(U_{B,\text{max}} = U_{E,\text{max}}\), because the total energy of the ideal circuit is conserved as energy oscillates entirely between the electric field of the capacitor and the magnetic field of the inductor.
- **B.** \(U_{B,\text{max}} = U_{E,\text{max}}\), because the current through the inductor and the charge on the capacitor reach their maximum values at the exact same instant in time.
- **C.** \(U_{B,\text{max}} < U_{E,\text{max}}\), because a portion of the initial electric energy is permanently lost as the magnetic field is established in the inductor.
- **D.** \(U_{B,\text{max}} > U_{E,\text{max}}\), because the inductor generates additional energy due to the back electromotive force produced during current growth.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118641/*