---
title: "Three point charges are fixed in a line along the \\(x\\)-axis as shown. The charges are \\(+Q\\) at \\(x = 0\\), \\(-Q\\) at \\(x = d\\), and \\(+Q\\) at \\(x = 2d\\). What is the total electrostatic potential energy of the three-charge system?"
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url: "https://nerd-notes.com/ubq/118096/"
date_modified: "2026-08-04T08:05:06+00:00"
---

# Three point charges are fixed in a line along the \(x\)-axis as shown. The charges are \(+Q\) at \(x = 0\), \(-Q\) at \(x = d\), and \(+Q\) at \(x = 2d\). What is the total electrostatic potential energy of the three-charge system?

Three point charges are fixed in a line along the \(x\)-axis as shown. The charges are \(+Q\) at \(x = 0\), \(-Q\) at \(x = d\), and \(+Q\) at \(x = 2d\). What is the total electrostatic potential energy of the three-charge system?

![A horizontal axis labeled x with three point charges rendered as small filled circles. The leftmost charge is labeled +Q and is positioned at x = 0. The middle charge is labeled -Q and is positioned at x = d. The rightmost charge is labeled +Q and is positioned at x = 2d. A double-headed horizontal arrow below the x-axis spans from x = 0 to x = d with the label d directly below it. A second double-headed horizontal arrow below the x-axis spans from x = d to x = 2d with the label d directly below it. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785830705-cxjCa9.jpg)

- **A.** \(-\dfrac{Q^2}{2\pi\varepsilon_0 d}\)
- **B.** \(-\dfrac{3 Q^2}{8\pi\varepsilon_0 d}\)
- **C.** \(-\dfrac{Q^2}{4\pi\varepsilon_0 d}\)
- **D.** \(+\dfrac{5 Q^2}{8\pi\varepsilon_0 d}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118096/*