AC Machines | Explain how in a 3 phase induction motor to a rotating magnetic field is developed.

Production of Rotating Magnetic Field in Three-phase Induction Motor: 

In three-phase induction motor, the three-phase stator windings are displaced in space by 120 and their three-phase currents are displaced in time by 120. So they produce the three-phase fluxes which are displaced in space by 120 and also in time by 120. Such fluxes give rise to the resultant rotating  magnetic field. 

When a three-phase supply is given to the three-phase stator winding, three phase currents flow and three-phase fluxes, which are displaced in space and also in time by 120 are produced. The wave forms of three-phase fluxes are shown in the figure. The directions of fluxes in the air-gap are assumed as shown in the figure.