How is the torque developed in an AC induction motor?

The torque developed in an AC induction motor fundamentally arises from the interaction of the magnetic fields produced by the stator and the rotor. When alternating current flows through the stator windings, it generates a rotating magnetic field. This rotating field induces a current in the rotor due to electromagnetic induction, which is a key principle of how induction motors operate.

As the induced current flows in the rotor, it becomes associated with its own magnetic field. The interaction between the rotor's magnetic field and the stator's rotating magnetic field creates a force that acts on the rotor, thereby producing torque. The continuous rotation of the stator's magnetic field works to keep the rotor in motion, allowing the motor to convert electrical energy into mechanical energy effectively.

This process is distinct from merely relying on friction or mechanical linkages, which do not play a primary role in torque generation in an induction motor. The reliance on electromagnetic fields and induction is what sets this type of motor apart and makes the interaction of the stator and rotor fields the key factor in torque production.