85. Salient pole rotors are used where
A. high frequency current is required
B. floor space is available in plenty
C. low and medium speed primemovers are available
D. high speed prime movers are available

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86. The power factor of an alternator is determined by its
A. primemover
B. excitation
C. speed
D. load

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87. If the input to the prime mover of an alternator is kept constant but the excitation is changed then
A. the power factor of the load remains constant
B. the reactive component of the output is changed
C. the active component of the output is changed
D. none of the above

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88. For parallel operation, A.C. polyphase alternators must have the same
A. kVA rating
B. excitation
C. speed
D. voltage rating

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89. Unlike D.C. generator kW rating, alternators are rated in
A. MW
B. kVAR
C. kWh
D. kVA

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90. Dirt accumulation in generators can cause
A. flashovers
B. overheating poor voltage regulation
C.(e) all of the above
D. none of the above

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91. An alternator running in parallel with other alternators all having automatic voltage regulators is to be taken off the bus. The usual procedure before opening the switch is to
A. reduce the power fed to the primemover
B. reduce alternator excitation
C. increase alternator excitation
D. none of the above

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