Related Questions

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 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.
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
Capacitors for power factor correction are rated in
A kW
B kVA
C kV
D kVAR
When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop
A inductor motor torque
B induction generator torque
C synchronous motor torque
D d.c. motor toque
A synchronous motor can be used as a synchronous capacitor when it is
A under-loaded
B over-loaded
C under-excited
D over-excited
A synchronous motor can develop synchronous torque
A when under loaded
B while over-excited
C only at synchronous speed
D below or above synchronous speed
For high value of diversity factor, a power station of given installed capacity will be in a position to supply
A Less number of consumers
B More number of consumers
C Neither (A) nor (B)
D Either (A) or (B)
Power plant having maximum demand more than the installed rated capacity will have utilisation factor
A equal to unity
B less than unity
C more than unity
D none of the above
When load on an over-excited or under excited synchronous motor is increased, rate of change of its armature current as compared with that of power factor is
A more
B less
C equal
D twice

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