What happens when Induction motor is loaded?

During no load operation the relative speed between stator magnetic field and rotor speed will be less (means slip is less). Hence small emf is generated which generates small currents and torque will be generated in such a manner sufficient to overcome the friction and windage losses.

When motor is loaded (Load applied to rotor), motor torque reduces as the load torque increases. Hence motor slows down (slip increases). As the motor slows down, the relative speed between rotor and stator magnetic field increases. This results in greater motor currents and generates greater motor torque to overcome the load torque. Thus as the load on the induction motor increases, motor slows down until sufficient torque is generated to overcome the applied load torque.