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 ha[[ens when the magnet passes the coil?

This generates electricity by electromagnetic induction. Everytime the magnet passes the electric coil, a change in magnetic flux suddenly causes a large potential difference, and hence a spark.

electomagnetic force

The magneto is a simple yet efficient device used to generate current in small one-cylinder gasoline engines. It consists of a permanent magnet attached to the flywheel and a stationary coil mounted adjacent to it.

When the magnet passes the coil, the magnetic field lines cut across the coil's windings, which induces a voltage. Let's break down the process step by step:

1. Rotation: As the engine's flywheel rotates, it carries the permanent magnet along with it. The magnet spins in close proximity to the coil.

2. Magnetic field: The rotating magnet produces a magnetic field. This field is considered dynamic because its strength and direction change as the magnet moves.

3. Magnetic field lines: The magnetic field lines extend from the magnet's north pole to its south pole. These field lines create a region of influence around the magnet.

4. Magnetic field interaction: As the magnet approaches the coil, the dynamic magnetic field lines begin to cut through the coil's windings. This dynamic interaction between the magnet's field lines and the coil induces voltage in the coil.

5. Electromagnetic induction: According to Faraday's law of electromagnetic induction, when a magnetic field cuts across a conductor (in this case, the coil), it induces a voltage in the conductor. This voltage is responsible for generating current.

6. Voltage and current: The induced voltage causes current to flow through the coil's windings. This current travels to the spark plug, providing the necessary electrical energy to create a spark and ignite the fuel-air mixture in the combustion chamber.

Overall, when the magnet passes the coil, the changing magnetic field induces a voltage in the coil through electromagnetic induction. This voltage generates the current required for the spark plug to ignite the fuel and initiate combustion in the engine.