A. speed
B. load
C. load angle
D. all of the above
Related Mcqs:
- A synchronous motor installed at the receiving end substation operates with such an excitation that it takes power at lagging power factor. Now if the applied voltage of the synchronous motor goes down, the power factor of the synchronous motor will___________?
A. remain same
B. go down
C. improve
D. none of the above - A synchronous motor can be used as a synchronous capacitor when it is____________?
A. under-loaded
B. over-loaded
C. under-excited
D. over-excited - A synchronous motor can develop synchronous torque:
A. when under loaded
B. while over-excited
C. only at synchronous speed
D. below or above synchronous speed - In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on___________?
A. load on the motor
B. d.c. excitation only
C. both the speed and rotor flux
D. none of the above - In a synchronous motor, the maximum power developed depends on all of the following except:
A. rotor excitation
B. maximum value of coupling angle
C. direction of rotation
D. supply voltage - In a synchronous motor, the magnitude of stator back e.m.f. & depends on_______________?
A. d.c. excitation only
B. speed of the motor
C. load on the motor
D. both the speed and rotor flux - The back e.m.f. in the stator of a synchronous motor depends on____________?
A. number of poles
B. flux density
C. rotor speed
D. rotor excitation
E. none of the above - An important advantage of a synchronous motor over wound round induction motor is that
A. its power factor may be varied at will
B. its speed is independent of supply frequency
C. its speed may be controlled more easily
D. none of the above - As the load is applied to a synchronous motor, the motor takes more armature current because
A. the increased load has to take more current
B. the rotor by shifting its phase backward causes motor to take more current
C. the back e.m.f. decreases causing an increase in motor current
D. the rotor strengthens the rotating field casuing more motor current - If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will__________?
A. stop
B. run as induction motor
C. function as static condenser
D. burn with dense smoke
