Related Questions

The 'crawling' in an induction motor is caused by
A high loads
B low voltage supply
C improper design of machine
D harmonics developed in the motor
A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is
A Slop speed operation
B High starting torque
C Low windage losses
D All of the above
Each of the following problem has a question and two statements which are labeled 1. and. Use the data given in 1. and 2. to decide whether the statements are sufficient to answer the question.Select one of the following . a.Statements (1) ALONE is sufficient,but (2) ALONE is not sufficient. b.Statements (2) ALONE is sufficient,but (1) ALONE is not sufficient. c. Both statement TOGETHER are sufficient but statement alone is sufficient . A fly crawls around the outside of a circle once.A second fly crawls around the outside of a square once.Which fly travels further ? (1) The diagonal of the square is equal to the diagonal of the circle.(2) The fly crawling around the circle took more time to complete has journey than the fly cawing around the square.
A A
B B
C C
D D
While starting a synchronous motor by induction motor action, field winding is usually
A connected to D.C. supply
B short-circuited by low resistance
C kept open-circuited
D none of the above
A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because
A synchronous motor has no slip
B stator supply is not required to produce magnetic field
C mechanical load on the rotor remains constant
D synchronous motor has large airgap
While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerting torque is produced by
A induction motor torque in field winding
B induction motor torque in damper winding
C eddy current and hysteresis torque in pole faces
D reHetance motor torque due to saliency of the rotor
E all of the above methods
Slip ring motor is preferred over squirrel cage induction motor where
A High starting torque is required
B Load torque is heavy
C Heavy pull out torque is required
D All of the above
The power factor of a synchronous motor is better than that of induction motor because
A stator supply is relieved of responsibility of producing magnetic field
B mechanical load on the motor can be adjusted
C synchronous motor runs at synchronous speed
D synchronous motor has large air gap
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
Of the 120 households in an area, 55 have cars, 35 have motor bikes, and 20 have both cars and motor bikes. How many of the households in the area have neither cares nor motor bikes?
A 110
B 90
C 50
D 30

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