Related Questions

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
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
If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then
A it runs at a slower speed
B the motor stops
C it continues to run at the same speed
D it runs at a very high speed
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
A synchronous motor is running on a load with normal excitation. Now if the load on the motor is increased
A power factor as well as armature current will decrease
B power factor as well as armature current will increase
C power factor will increase but armature current will decrease
D power factor will decrease and armature current will increase
The Head of a newly formed government desires to appoint five of the six elected members A,B,C,D,E and F to portfolios of Home,Power,Defence ,Telecom and Finance.F dose not want any portfolio if D gets one the five.C wants either Home or Finance or on portfolio.B says that if D gets either Power or Telecom then she must get the other one.E insists on a portfolio if A gets one. If a gets Home and C gets Finance,then which is NOT a valid assignment for Defence and Telecom?
A B-Defence,D-Telecom
B B-Defence,E-Telecom
C F-Defence,B-Telecom
D D-Defence,B-Telecom
What are the salient features of the new scheme? Choose the meaning of salient.
A silent
B main
C minor
D stable
If excitation of a synchronous motor running with a constant load is decreased from its normal value, ignoring effects of armature reaction, it leads to
A increase in both armature current and power factor angle
B increase in back e.m.f. but decrease in armature current
C increase in both armature current and power factor which is lagging
D increase in torque angle but decrease in back e.m.f.
In a synchronous motor running with fixed excitation, when the load is increased three times, its torque angle becomes approximately
A One-third
B Twice
C Thrice
D Six times
If in a synchronous motor, driving a given mechanical load and drawing current at a leading power factor from constant voltage supply its field excitation is increased, its power factor
A will become more
B will become less
C will remain unchanged
D none of the above.

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