---
title: "An ideal LC circuit consists of an inductor with inductance \\(L\\) and a capacitor with capacitance \\(C\\). At time \\(t = 0\\), the capacitor holds a maximum charge \\(Q_0\\) and the current in the circuit is zero. Which of the following expressions gives the magnitude of the current \\(I\\) in the circuit when the charge on the capacitor is \\(q\\)?"
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url: "https://nerd-notes.com/ubq/118713/"
date_modified: "2026-08-04T08:13:51+00:00"
---

# An ideal LC circuit consists of an inductor with inductance \(L\) and a capacitor with capacitance \(C\). At time \(t = 0\), the capacitor holds a maximum charge \(Q_0\) and the current in the circuit is zero. Which of the following expressions gives the magnitude of the current \(I\) in the circuit when the charge on the capacitor is \(q\)?

An ideal LC circuit consists of an inductor with inductance \(L\) and a capacitor with capacitance \(C\). At time \(t = 0\), the capacitor holds a maximum charge \(Q_0\) and the current in the circuit is zero. Which of the following expressions gives the magnitude of the current \(I\) in the circuit when the charge on the capacitor is \(q\)?

![A simple single-loop schematic diagram of an LC circuit drawn with black lines on a clean white background. On the left side, a parallel-plate capacitor is positioned vertically, labeled with capacitance C and charge q on its top plate. On the right side, an inductor is positioned vertically, represented by four smooth curved wire loops and labeled with inductance L. A continuous wire loop connects the top of the capacitor to the top of the inductor, and the bottom of the capacitor to the bottom of the inductor. An arrow along the top wire points to the right, indicating current I. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785831230-caG0lR.jpg)

- **A.** \(I = \dfrac{1}{\sqrt{LC}} (Q_0 - q)\)
- **B.** \(I = \dfrac{1}{\sqrt{LC}} \sqrt{Q_0^2 - q^2}\)
- **C.** \(I = \dfrac{1}{\sqrt{LC}} \left( \dfrac{Q_0^2 - q^2}{Q_0} \right)\)
- **D.** \(I = \dfrac{1}{\sqrt{LC}} \sqrt{Q_0^2 + q^2}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118713/*