---
title: "Three concentric, thin, spherical conducting shells have radii \\(R\\), \\(2R\\), and \\(3R\\). The innermost shell carries a fixed net charge of \\(+Q\\), and the outermost shell carries a fixed net charge of \\(+Q\\). The middle shell is initially uncharged, momentarily connected to ground by a thin conducting wire, and then disconnected. What is the resulting net electric charge on the middle shell?"
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url: "https://nerd-notes.com/ubq/124505/"
date_modified: "2026-09-28T14:08:24+00:00"
---

# Three concentric, thin, spherical conducting shells have radii \(R\), \(2R\), and \(3R\). The innermost shell carries a fixed net charge of \(+Q\), and the outermost shell carries a fixed net charge of \(+Q\). The middle shell is initially uncharged, momentarily connected to ground by a thin conducting wire, and then disconnected. What is the resulting net electric charge on the middle shell?

Three concentric, thin, spherical conducting shells have radii \(R\), \(2R\), and \(3R\). The innermost shell carries a fixed net charge of \(+Q\), and the outermost shell carries a fixed net charge of \(+Q\). The middle shell is initially uncharged, momentarily connected to ground by a thin conducting wire, and then disconnected. What is the resulting net electric charge on the middle shell?

![Cross-sectional view of three concentric circles centered at a single central point. The innermost circle has radius R, shown with a thin solid black outline and labeled +Q near its top edge. A straight arrow points from the center to this inner circle at a 135-degree angle, labeled R. The second concentric circle has radius 2R, drawn with a thin solid black outline; a straight arrow points from the center to its edge at a 45-degree angle, labeled 2R. From the bottom of this second circle, a thin line extends downward through a small gap in the outer circle and terminates at a standard horizontal three-line ground symbol. The outermost circle has radius 3R, drawn with a thin solid black outline and labeled +Q near its top edge; a straight arrow points from the center to its edge horizontally to the right, labeled 3R. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-concentric-shells-1790604504-EGWcS3.jpg)

- **A.** \(-2Q\)
- **B.** \(-\dfrac{5}{3}Q\)
- **C.** \(-Q\)
- **D.** \(-\dfrac{2}{3}Q\)

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