How does stator help rotor to rotate in AC motor?

The stator and rotor in an AC motor interact to create a rotating magnetic field, which causes the rotor to spin. Here's a step-by-step explanation:

1. The stator is the stationary part of the motor, which includes the motor casing, as well as two or more magnetic pole pieces. The poles are usually built up of laminations of silicon steel, to reduce hysteresis and eddy current losses.

2. When an AC voltage is applied to the stator windings, it creates a magnetic field that rotates around the stator. This is known as the stator's magnetic field.

3. The rotor, which is the rotating part of the motor, is located inside the stator and is mounted on the motor's shaft. The rotor also has windings, which are connected to a commutator.

4. The stator's rotating magnetic field induces a current in the rotor windings, due to Faraday's law of electromagnetic induction. This current creates its own magnetic field around the rotor.

5. The interaction between the stator's magnetic field and the rotor's magnetic field creates a force that causes the rotor to turn. This is due to the principle that like magnetic poles repel each other and unlike magnetic poles attract each other.

6. The rotor continues to turn as long as the stator's magnetic field is rotating and the current is flowing in the rotor windings.

In summary, the stator helps the rotor to rotate in an AC motor by creating a rotating magnetic field that induces a current in the rotor, which in turn creates its own magnetic field. The interaction between these two magnetic fields creates a force that causes the rotor to turn.