A circular armature coil is used in a motor with a uniform magnetic field of 2.65 T. The coil has a diameter 85 cm, a resistance of 50 ?, and generates a back emf of 94 VRMS when running a full speed under no load at the angular frequency ?A.
(A) At what angular frequency, ?B relative to ?A does the coil be need to be rotated to generate a back emf of 74VRMS?
(B) If this motor is operating on 120 VRMS now with a load (e.g running a fan) and at the angular frequency ?A, how much current is flowing throught the motor?