---
title: "A parallel-plate capacitor is filled with a dielectric material of dielectric constant \\(\\kappa = 3.0\\). The capacitor is connected to a power supply until it acquires a potential difference \\(V_0\\) and stored electrostatic energy \\(U_0\\), and is then disconnected from the power supply, leaving it isolated. The dielectric slab is then completely removed from between the plates. Which of the following correctly pairs the new potential difference \\(V_f\\) across the plates and the new stored electrostatic energy \\(U_f\\) in terms of \\(V_0\\) and \\(U_0\\)?"
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url: "https://nerd-notes.com/ubq/118265/"
date_modified: "2026-08-04T08:08:29+00:00"
---

# A parallel-plate capacitor is filled with a dielectric material of dielectric constant \(\kappa = 3.0\). The capacitor is connected to a power supply until it acquires a potential difference \(V_0\) and stored electrostatic energy \(U_0\), and is then disconnected from the power supply, leaving it isolated. The dielectric slab is then completely removed from between the plates. Which of the following correctly pairs the new potential difference \(V_f\) across the plates and the new stored electrostatic energy \(U_f\) in terms of \(V_0\) and \(U_0\)?

A parallel-plate capacitor is filled with a dielectric material of dielectric constant \(\kappa = 3.0\). The capacitor is connected to a power supply until it acquires a potential difference \(V_0\) and stored electrostatic energy \(U_0\), and is then disconnected from the power supply, leaving it isolated. The dielectric slab is then completely removed from between the plates. Which of the following correctly pairs the new potential difference \(V_f\) across the plates and the new stored electrostatic energy \(U_f\) in terms of \(V_0\) and \(U_0\)?

![Two identical parallel horizontal metal plates of length L are drawn one above the other with a gap between them. In the left diagram labeled Initial, a shaded rectangular dielectric slab completely fills the space between the plates with the text kappa = 3.0 centered inside it. Open wire leads extend vertically outward from the top and bottom plates to represent an isolated circuit. In the right diagram labeled Final, the same two horizontal metal plates are shown with an empty gap, and the shaded dielectric slab is positioned to the right of the plates with a horizontal arrow pointing to the right indicating its removal. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1785830909-n7sIz8.jpg)

- **A.** \(V_f = \dfrac{1}{3}V_0\) and \(U_f = \dfrac{1}{3}U_0\)
- **B.** \(V_f = \dfrac{1}{3}V_0\) and \(U_f = 3U_0\)
- **C.** \(V_f = 3V_0\) and \(U_f = 9U_0\)
- **D.** \(V_f = 3V_0\) and \(U_f = 3U_0\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118265/*