Diagram shows conditions in a synchronous motor when operating in synchronism and at no load. When the motor
is loaded the rotor will drop back along the red curve C, the curve of synchronous torque, sufficiently to develop the load torque. C
is the resultant of magnetic reluctance torque, A, and the definite polarity torque, B. The maximum synchronous torque is reached
at about 70 electrical degrees lag of the rotor.