FAA Powerplant Written Practice Test

Which of the following circuits are part of a high-tension magneto?

1. Magnetic and secondary

2. Primary and secondary

3. Magnetic, primary, and secondary

4. Ignition and starting

The correct answer is: Magnetic, primary, and secondary

In a high-tension magneto system, the components involved are crucial for generating the necessary high-voltage spark required for engine ignition. The correct answer identifies that the circuit includes the magnetic, primary, and secondary components. The magnetic circuit is responsible for creating the magnetic field necessary for inducing electrical current. This process begins when the magnet rotates, generating magnetic flux through the primary winding. The primary circuit consists of a coil with relatively few turns of wire that is connected to the magneto. When the magnetic field changes due to the rotation of the magnet, it induces a voltage in the primary winding. Then, in the secondary circuit, which contains many more turns of wire compared to the primary, the induced voltage from the primary circuit is transformed into a much higher voltage. This high tension is essential for creating a spark across the spark plug, allowing for the ignition of the engine's fuel mixture. Understanding that all three components—the magnetic, primary, and secondary circuits—work together for the magneto's operation highlights why this answer is correct. Each part plays a unique but interdependent role in generating and delivering the high-voltage spark necessary for engine performance.