How does a three-phase induction motor work?

Three-phase induction motors work on electromagnetic induction between stator and rotor. Three-phase supply to stator windings creates a rotating magnetic field (RMF) at synchronous speed (Ns = 120f/P). This RMF induces current in rotor conductors, creating rotor magnetic field that follows stator field. The rotor always runs slightly slower than synchronous speed - this difference (slip) is necessary to maintain induced current. Typical slip is 2-5% at full load.