Synchronous motors are generally not self-starting because
A. the direction of rotation is not fixed
B. the direction of instantaneous torque reverses after half cycle
C. starters cannot be used on these machines
D. starting winding is not provided on the machines
Answer:B
Synchronous motors are generally not self-starting because
A. the direction of rotation is not fixed B. the direction of instantaneous torque reverses after half cycle C. starters cannot be used on these machines D. starting winding is not provided on the machines
Explanation: In synchronous motors, the stator has 3 phase windings and is excited by 3 phase supply whereas the rotor is excited by DC supply.