Related Questions

If in a synchronous motor, driving mechanical load and drawing current at lagging power factor from constant voltage supply, its field excitation is increased, then its power factor
A become more
B become less
C remain constant
D none of the above
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.
In a substation the following equipment is not installed
A Exciters
B Series capacitors
C Shunt reactors
D Voltaire transformers
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
A brother and sister leave home for school. The brother goes 0.5 km East, then turns right and goes 3.5 km and reaches his school. The sister goes 2.5 km North, then 1 km West, then turns left and goes 6 km and reaches her school. Where is the brother's school with respect to the sister's school?
A 0.5 km East
B 1.5 km West
C 0.5 km West
D 1.5 km East
Larger buildings may be supplied with a medium voltage electricity supply, and will required a substation or mini-sub. What is the main item of equipment contained in these?
A Transformer
B Transponder
C Transducer
D Converter
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
A synchronous motor running with normal excitation adjusts to load increases essentially by increase in
A back e.m.f.
B armature current
C power factor
D torque angle
A synchronous motor is running with normal excitation. When the load is increased, the armature current drawn by it increases because
A Speed of the motor is reduced
B Power factor is decreased
C Eb (back e.m.f.) becomes less than V (applied voltage)
D Er (net resultant voltage) in armature is increased

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