A Best Way To Crack Gorenment Job Exams

Electrical Engineering Objective Questions { Alternators }



92. Due to which of the following reasons concentrated windings are not used in alternators?
A. Concentrated windings increase voltage harmonics
B. Concen trated windings decrease induced e.m.f/phase
C. Concentrated windings increase copper-to-iron ratio thereby decreasing the capacity
D. Concentrated windings require deep slots for accommodation which leads to increased armature leakage and reactance

93. A stationary alternator should not be connected to a live bus-bar because it
A. will get short-circuited
B. will distrub generated e.m.fs. of other alternators connected in parallel
C. is likely to run as a synchronous motor
D. will decrease but-bar voltage though momentarily

94. The power drawn by the prime-mover of an alternator, under no-load condition, goes to
A. meet copper losses both in armature and rotor windings
B. produce power in armature
C. meet no-load losses
D. produce e.m.f. in armature winding

95. In a larger generator dampers
A. reduce frequency fluctuations
B. increase stability
C. reduce voltage fluctuations
D. none of the above

96. The choice of field construction, in an alternator, is basically determined by
A. generated voltage needed by the customers
B. comparative cost of the field systems
C. supply frequency required by the consumers
D. the kind of energy source available in the geographic location

97. The load between two steam-driven alternators operating in parallel may be adjusted by varying
A. steam supply to their prime movers
B. speed of the alternators
C. field strengths of the alternators
D.(b) power faciors of the alternators

98. The overheating of generator winding result in
A. reduced life of the machine
B. does not have any significant effect
C. reduces generated voltage
D. reduces power factor

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