Item RG112002: An engineer can increase the electrostatic potential energy of a capacitor by increasing the distance between the two plates.
A capacitor is a device that is used to store an electrostatic charge. It is composed of two large conductive plates separated by a nonconductive insulating layer.
An engineer would like to increase the electrostatic potential energy of a capacitor. Which of the following changes could she make to the capacitor to increase the electrostatic potential energy?
- Increase the distance between the two plates by increasing the thickness of the insulating layer
- Decrease the distance between the two plates by decreasing the thickness of the insulating layer
- The only way to increase the electrostatic potential energy of a capacitor is to replace the insulating layer.
- It is not possible to increase the electrostatic potential energy of a capacitor.
- Distribution of Responses

- Scale Score for Item Difficulty
(200[Easy]-800[Difficult]) - 530
- Students Responding Correctly
Group | Correct | Total | Percent |
---|---|---|---|
Overall | 413 | 1538 | 27% |
Grades | |||
4–5 | N/A | N/A | N/A |
6–8 | 207 | 791 | 26% |
9–12 | 206 | 747 | 28% |
Gender | |||
Male | 207 | 738 | 28% |
Female | 196 | 771 | 25% |
Primary Language | |||
English | 370 | 1389 | 27% |
Other | 33 | 109 | 30% |
- Disciplinary Core Ideas
- PS3.A A system of objects may also contain stored (potential) energy, depending on their relative positions.
PS3.C When two objects interacting through a field change relative position, the energy stored in the field is changed. - NRC Framework
- Energy is also stored in the electric fields between charged particles and the magnetic fields between magnets, and it changes when these objects are moved relative to one another.