In a three-phase, squirrel-cage type, and induction motor, how is the primary rotating magnetic field established?

Correct Answer: Option D — application of a three-phase voltage supply to the stator windings

Applying three-phase voltage to the stator windings creates a rotating magnetic field. This field induces current in the rotor bars via electromagnetic induction. Per IEEE 45 standards, this interaction between the stator's rotating field and the rotor's induced field generates the torque necessary to drive the motor load.