Which component in an alternator is responsible for producing the magnetic field that induces current?

Which component in an alternator is responsible for producing the magnetic field that induces current?

• A. Stator
• B. Regulator
• C. Diode pack
• D. Rotor

Answer: (D)

The rotor is the part that creates the magnetic field. In most automotive alternators the rotor carries the field winding and is energized with DC from the regulator. That DC turns the rotor into a strong electromagnet. As the rotor spins inside the stator, its rotating magnetic field sweeps past the stator windings, inducing current in the stator through electromagnetic induction. The regulator controls how much current flows in the rotor, which fixes the field strength and helps regulate the overall output. The stator is where the induced current appears, the diode pack rectifies that AC to DC, and the regulator adjusts the field—not the magnetic source itself.

The rotor is the part that creates the magnetic field. In most automotive alternators the rotor carries the field winding and is energized with DC from the regulator. That DC turns the rotor into a strong electromagnet. As the rotor spins inside the stator, its rotating magnetic field sweeps past the stator windings, inducing current in the stator through electromagnetic induction. The regulator controls how much current flows in the rotor, which fixes the field strength and helps regulate the overall output. The stator is where the induced current appears, the diode pack rectifies that AC to DC, and the regulator adjusts the field—not the magnetic source itself.