A. low horsepower motors
B. variable speed motors
C. high horsepower motors
D. high speed motors
Related Mcqs:
- In squirrel cage induction motors, the rotor slots are usually given slight skew in order to__________?
A. reduce windage losses
B. reduce eddy currents
C. reduce accumulation of dirt and dust
D. reduce magnetic hum - Star-delta starting of motors is not possible in case of____________?
A. single phase motors
B. variable speed motors
C. low horse power motors
D. high speed motors - In medium sized induction motors, the slip is generally around___________?
A. 0.04%
B. 0.4%
C. 4%
D. 14% - In case of the induction motors the torque is___________?
A. inversely proportional to (Vslip)
B. directly proportional to (slip)2
C. inversely proportional to slip
D. directly proportional to slip - Which type of bearing is provided in small induction motors to support the rotor shaft ?
A. Ball bearings
B. Cast iron bearings
C. Bush bearings
D. None of the above - 5 H.P., 50-Hz, 3-phase, 440 V, induction motors are available for the following r.p.m. Which motor will be the costliest ?
A. 730 r.p.m.
B. 960 r.p.m.
C. 1440 r.p.m.
D. 2880 r.p.m. - In three-phase induction motors sometimes copper bars are placed deep in the rotor to___________?
A. improve starting torque
B. reduce copper losses
C. improve efficiency
D. improve power factor - In case of 3-phase induction motors, plugging means__________?
A. pulling the motor directly on line without a starter
B. locking of rotor due to harmonics
C. starting the motor on load which is more than the rated load
D. interchanging two supply phases for quick stopping - Blocked rotor test on induction motors is used to find out?
A. leakage reactance
B. power factor on short circuit
C. short-circuit current under rated voltage
D. all of the above - The starting torque of a 3-phase squirrel cage induction motor is____________?
A. twice the full load torque
B. 1.5 times the full load torque
C. equal to full load torque
