FAA Powerplant Written Practice Test

What component is shared by both ignition systems in a dual magneto?

1. Capacitor

2. Transformator

3. Rotating magnet

4. Coil windings

The correct answer is: Rotating magnet

In a dual magneto ignition system, the rotating magnet is a crucial component that both ignition systems share. This is because the dual magneto setup consists of two separate ignition systems that are mechanically linked. The rotating magnet is responsible for generating the necessary magnetic field, which induces an electrical current in the coil windings as it turns. Since both sides of the dual magneto rely on this rotating magnet to produce the spark for ignition, it serves as the common element that connects the two systems. This redundancy is essential for improving engine reliability, as if one ignition system fails, the other can still operate using the same rotating magnet, ensuring continuous engine performance. Understanding the function of the rotating magnet helps technicians appreciate how dual ignition systems work effectively to maintain engine operation.