Chapter 4: Q14DQ (page 980)
Small one-cylinder gasoline engines sometimes use a device called a magneto to supply current to the spark plug. A permanent magnet is attached to the flywheel, and a stationary coil is mounted adjacent to it. Explain how this device is able to generate current. What happens when the magnet passes the coil?
Short Answer
When flywheel rotates the magnet linked to it moves in relation to the stationary coil, thus magnetic field at the coil changes generating emf which causes current to flow.