When the breaker points open in a magneto, what occurs?

When the breaker points open in a magneto, what occurs?

• A. The secondary voltage increases
• B. The primary current is interrupted
• C. The rotor stalls
• D. The magnet stops rotating

Answer: (B)

When breaker points open, the current in the magneto’s primary circuit is interrupted. That sudden break causes the magnetic field to collapse rapidly, and the changing flux induces a high voltage in the secondary winding. This high voltage travels to the spark plug and creates the spark that ignites the fuel-air mixture. The rotor and magnet keep turning with the engine; nothing stalls. The key idea is that opening the points stops the primary current, and the resulting rapid flux change generates the spark.

When breaker points open, the current in the magneto’s primary circuit is interrupted. That sudden break causes the magnetic field to collapse rapidly, and the changing flux induces a high voltage in the secondary winding. This high voltage travels to the spark plug and creates the spark that ignites the fuel-air mixture. The rotor and magnet keep turning with the engine; nothing stalls. The key idea is that opening the points stops the primary current, and the resulting rapid flux change generates the spark.