How does an induction motor function?

• A. Through the use of permanent magnets
• B. By varying the stator voltage
• C. Via electromagnetic induction from a rotating magnetic field
• D. By winding variations only

Answer: (C)

An induction motor operates based on the principle of electromagnetic induction, specifically utilizing the interaction between a rotating magnetic field generated by the stator and the induced current in the rotor. When alternating current is supplied to the stator windings, it creates a rotating magnetic field. This rotating field passes through the rotor, inducing an electromotive force (EMF) due to Faraday's law of electromagnetic induction. As a result, current flows in the rotor conductors, causing the rotor to turn and follow the rotating magnetic field.

This process is essential for the motor's operation, as the rotor does not require any external power supply to function; it relies entirely on the electromagnetic interaction produced by the stator. Thus, the mechanical motion of the rotor is generated solely through this induced magnetic interaction, demonstrating the fundamental working principle of induction motors.