What type of magnetic field is produced by field coils in a typical AC induction motor?

In a typical AC induction motor, the field coils are designed to create a rotating magnetic field. This phenomenon is crucial for the operation of the motor, as it induces motion in the rotor, allowing the motor to convert electrical energy into mechanical energy. The rotating magnetic field is generated by supplying alternating current (AC) to the stator coils, which causes the magnetic field to change direction periodically.

This alternating pattern produces a field that rotates around the rotor, which is positioned within this magnetic field. As the magnetic field moves, it interacts with the rotor, inducing an electromotive force (EMF) that causes the rotor to turn. This principle is at the heart of how AC induction motors operate efficiently and is key to their widespread use in various applications.

While a static magnetic field and an electromagnetic field are related concepts, they do not accurately describe the dynamic behavior of the field coils in an AC induction motor. The term "distributed magnetic field" also doesn't capture the essential characteristic of rotating that is critical for the motor's operation. Thus, the identification of the magnetic field produced by these coils as a rotating magnetic field is fundamental to understanding how the motor works.