Which of the following correctly describes the role of electric pumps in the Cessna 172 fuel system?

The role of electric pumps in the Cessna 172 fuel system is best described by their function during engine start and in-flight operations. During engine start, the electric fuel pump is activated to provide an adequate fuel supply to start the engine without relying solely on the engine-driven fuel pump. This is especially important because it ensures that the engine receives enough fuel even when it is not yet generating sufficient suction to draw fuel from the tanks effectively.

Furthermore, electric pumps assist during flight, particularly in situations where the engine-driven pump might become less effective, such as during low fuel situations or certain maneuvers. They are designed to provide a consistent fuel flow to maintain engine operation and performance.

In contrast, electric pumps are not limited to ground operations and are used beyond just starting the engine. They do not supply fuel directly to the cylinders but rather feed into the fuel system leading towards the engine. Additionally, while electric pumps may operate continuously when activated, they do not necessarily function regardless of engine speed; they are designed to support the engine's operational needs rather than run constantly.