In either PM or induction, torque is developed from the interaction of the magnetic fields. In the PM, there is no current path in the rotor, so no 'induced' magnetics. In the induction motor, the rotor consists of bars that are elelctrically linked. These bars allow the 'induced' current to flow which in turn sets up a rotor field, leading to the rise of CEMF.IN ac motor the rotor is a permanent magnet. when the magnet rotates because the stator are made electromagnet, won't there be any emf induced in the magnet because of electromagnet induction?