What is a key feature of the capacitance type (electronic) fuel quantity indicator?

The capacitance type fuel quantity indicator is defined by its design and functionality, which emphasizes the absence of moving parts within the fuel tank. This feature enhances reliability and durability, as there are fewer components that can wear out or fail over time. In such systems, the fuel quantity is measured through the change in capacitance as the fuel level varies. Since capacitance is dependent on the dielectric properties of the medium between two conductive plates, the level of fuel affects the capacitance without the need for mechanical movement.

This electronic approach allows for accurate fuel level measurement and reduces the maintenance requirements associated with moving parts, thus improving the overall performance and lifespan of the fuel quantity indicator. The other options describe different mechanisms or aspects that do not align with the functionality of capacitance type indicators. For instance, the presence of a float-operated variable capacitor suggests a mechanical component, which contradicts the key feature of having no moving parts.