A. become unstable
B. draw excessive armature current and may burn out
C. fall out of synchronism and come to stand still
D. run as induction motor
Related Mcqs:
- For which of the applications a reluctance motor is preferred ?
A. Electric shavers
B. Refrigerators
C. Signalling and timing devices
D. Lifts and hoists - Which of the following statements regarding reluctance-start motor is incorrect ?
A. It is similar to reluctance motor
B. It is basically an induction motor and not a synchronous one
C. So far as its basic working principle is concerned, it is similar to shaded pole motor
D. the air-gap between rotor and salient poles is non- uniform - Which of the following statements regarding a reluctance motor is incorrect ?
A. It cannot be reversed, ordinarily
B. It requires no D.C. field excitation for its operation
C. It is nothing else but a single-phase, salient pole synchronous-induction motor
D. Its squirrel cage-rotor is of unsym-metrical magnetic construction in order to vary reluctance path between stator and rotor - If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in_________?
A. damage to the starting winding
B. damage to the centrifugal switch
C. overloading of running winding
D. none of the above - Centrifugal switch disconnects the auxiliary winding of the motor at about ______ percent of synchronous speed?
A. 30 to 40
B. 70 to 80
C. 80 to 90
D. 100 - Two-value capacitor motor finds increased application as compressor motor in small home air-conditioners because_____________?
A. it is comparatively cheaper
B. it has almost non-destructible capacitor
C. it has low starting as well as running currents at relatively high power factor
D. it is quiet in operation - The speed/load characteristics of a universal motor is same as that of_____________?
A. A.C. motor
B. D.C. shunt motor
C. D.C. series motor
D. none of the above - In case of a shaded pole motor the direction of rotation of the motor is__________?
A. from main pole to shaded pole
B. from shaded pole to main pole
C. either of the above depending on voltage
D. either of the above depending on power factor - In case of high speed universal motor which of the following needs more attention?
A. End play
B. Air gap
C. Insulation in rotor
D. Balancing of rotor - A reluctance motor____________?
A. is self-starting
B. is constant speed motor
C. needs no D.C. excitation
D. all of the above
