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title: "Two identical parallel-plate capacitors, 1 and 2, each have capacitance \\(C_0\\) and are initially charged so that each stores electrostatic potential energy \\(U_0\\). Capacitor 1 is disconnected from its charging source, while Capacitor 2 remains connected to a battery that maintains a constant electric potential difference across its plates. A slab of uncharged dielectric material with dielectric constant \\(\\kappa > 1\\) is then inserted to completely fill the space between the plates of each capacitor. Which row in the table correctly describes how the electric potential difference across Capacitor 1, the electrostatic potential energy stored in Capacitor 1, and the electrostatic potential energy stored in Capacitor 2 change after the slabs are inserted?  | | Potential Difference Across Capacitor 1 | Stored Energy in Capacitor 1 | Stored Energy in Capacitor 2 | |—|—|—|—| | (A) | Decreases | Decreases | Increases | | (B) | Decreases | Decreases | Decreases | | (C) | Remains constant | Decreases | Increases | | (D) | Decreases | Increases | Decreases |"
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url: "https://nerd-notes.com/ubq/121103/"
date_modified: "2026-08-23T04:57:55+00:00"
---

# Two identical parallel-plate capacitors, 1 and 2, each have capacitance \(C_0\) and are initially charged so that each stores electrostatic potential energy \(U_0\). Capacitor 1 is disconnected from its charging source, while Capacitor 2 remains connected to a battery that maintains a constant electric potential difference across its plates. A slab of uncharged dielectric material with dielectric constant \(\kappa > 1\) is then inserted to completely fill the space between the plates of each capacitor. Which row in the table correctly describes how the electric potential difference across Capacitor 1, the electrostatic potential energy stored in Capacitor 1, and the electrostatic potential energy stored in Capacitor 2 change after the slabs are inserted?

| | Potential Difference Across Capacitor 1 | Stored Energy in Capacitor 1 | Stored Energy in Capacitor 2 |
|—|—|—|—|
| (A) | Decreases | Decreases | Increases |
| (B) | Decreases | Decreases | Decreases |
| (C) | Remains constant | Decreases | Increases |
| (D) | Decreases | Increases | Decreases |

Two identical parallel-plate capacitors, 1 and 2, each have capacitance \(C_0\) and are initially charged so that each stores electrostatic potential energy \(U_0\). Capacitor 1 is disconnected from its charging source, while Capacitor 2 remains connected to a battery that maintains a constant electric potential difference across its plates. A slab of uncharged dielectric material with dielectric constant \(\kappa > 1\) is then inserted to completely fill the space between the plates of each capacitor. Which row in the table correctly describes how the electric potential difference across Capacitor 1, the electrostatic potential energy stored in Capacitor 1, and the electrostatic potential energy stored in Capacitor 2 change after the slabs are inserted?

| | Potential Difference Across Capacitor 1 | Stored Energy in Capacitor 1 | Stored Energy in Capacitor 2 |
|---|---|---|---|
| (A) | Decreases | Decreases | Increases |
| (B) | Decreases | Decreases | Decreases |
| (C) | Remains constant | Decreases | Increases |
| (D) | Decreases | Increases | Decreases |

![On the left, labeled Capacitor 1, two horizontal parallel line segments represent plates of length L separated by a vertical gap d. Above the gap, an arrow labeled with dielectric constant \kappa points downward into the gap, aligned with a lightly shaded rectangle representing a dielectric slab of thickness d. On the right, labeled Capacitor 2, two identical horizontal parallel line segments of length L are separated by gap d, with solid connecting wires extending from the plates to a DC voltage source labeled V_0. Above Capacitor 2, an identical shaded rectangle and downward arrow labeled \kappa indicate an identical dielectric slab being inserted into the gap. No other labels, lines, text, or axes appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787461074-qjK2OT.jpg)

- **A.** Row A
- **B.** Row B
- **C.** Row C
- **D.** Row D

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121103/*