A biomedical engineer is designing a flexible capacitive pressure sensor. The sensor consists of a thin elastomeric dielectric film sandwiched in contact between two flexible conductive plates of a fixed area AAA.
The physical properties of four candidate elastomer films are listed in the table below:
| Film | Elastomer material | Relative permittivity εr\varepsilon_rεr | Thickness ddd / mm |
|---|---|---|---|
| A | Silicone | 2.8 | 0.40 |
| B | Polyurethane | 6.4 | 1.60 |
| C | Fluorosilicone | 5.6 | 0.70 |
| D | Natural Rubber | 3.2 | 0.50 |
Determine which elastomer film will produce the maximum capacitance. Justify your answer with appropriate calculations.
63 exam-style questions on AQA A Level Physics Capacitance (A-level only), covering Capacitance (A-level only), Parallel plate capacitor (A-level only), Energy stored by a capacitor (A-level only), and Capacitor charge and discharge (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.