Positive or negative value of current doesn’t affect the torque direction. The interaction/electromagnetic torque = isirdMsr/dθr, here the direction of is and ir changes the torque. 10. Singly and doubly excited magnetic systems applications are respectively:
A. loud speakers and tachometers
B. synchronous motors and moving iron instruments
C. DC shunt machines and solenoids
D. reluctance motors and synchronous motors
Answer:A
Positive or negative value of current doesn’t affect the torque direction. The interaction/electromagnetic torque = isirdMsr/dθr, here the direction of is and ir changes the torque. 10. Singly and doubly excited magnetic systems applications are respectively:
A. loud speakers and tachometers B. synchronous motors and moving iron instruments C. DC shunt machines and solenoids D. reluctance motors and synchronous motors
Explanation: Reluctance motors can work on single excitation, and synchronous motors require double excitation. 11. Electromagnetic torque in rotating electrical machinery is present when ________