Synchronous Motors

A. zero or 0.8 leading
B. unity or 0.8 lagging
C. unity or 0.8 leading
D. unity or zero

A. d.c. source
B. armature input
C. motor input
D. supply lines

A. supply voltage fluctuates
B. load in motor varies
C. excitation winding gets disconnected
D. supply voltage frequency changes

A. 1%
B. 0.5%
C. positive
D. zero

A. Windage loss
B. Bearing friction loss
C. Copper loss
D. Core loss

A. armature current and power factor
B. terminal voltage and load factor
C. power factor and field current
D. field current and armature current

A. leading current
B. lagging current
C. both A. and (b)
D. none of the above

A. the force required to accelerate the rotor to the synchronous speed in an instant is absent
B. the starting device to accelerate the rotor to near synchronous speed is absent
C. a rotating magnetic field does not have enough poles
D. the rotating magnetic field is produced by only 50 Hz frequency currents

A. V
B. V312
C. V2
D. 1/V

A. no slip-rings
B. one slip-ring
C. two slip-rings
D. three slip-rings