What property of a dielectric is utilized in fuel gauge operation?

• A. Conducting electricity.
• B. Storing electrical charge.
• C. Generating a magnetic field.
• D. Providing mechanical support.

Answer: (B)

The key concept is that a dielectric stores electrical energy by polarizing in an electric field, which changes a capacitor’s capacitance. In a capacitive fuel gauge, two plates form a capacitor with the fuel between them acting as the dielectric. As the fuel level changes, the amount and type of dielectric between the plates changes, altering the capacitance the gauge measures. Since capacitance depends on the dielectric constant of the material between the plates, the fuel gauge uses this property to infer fuel quantity. The other options describe functions (conducting electricity, generating a magnetic field, providing mechanical support) that aren’t characteristics a dielectric provides in this context.