Cogging in an induction motor is a phenomenon where the motor fails to start due to the magnetic locking between the stator and rotor teeth at the time of starting. When the stator and rotor slots are equal or have an integral ratio, strong alignment forces are produced between the stator and rotor at the instant of starting, which may create an alignment torque greater than the accelerating torque, resulting in the failure of the motor to start. This phenomenon is also known as teeth locking or magnetic locking. Cogging can be reduced or eliminated by using a skewed rotor or stator, which helps to break the symmetry of the motor.