单选题When two AC generators are being paralleled, the breaker should be closed with the synchroscope pointer mating in the （）A slow direction, just before the 12 o'clock positionB fast direction, just after the 12 o'clock positionC fast direction, just befo

When the prime movers of two paralleled generators are equipped with mechanical-hydraulic governors, and are operating within their designed range, the unit with the least amount of speed droop will .

A.pick up more of any increase in load

B.pick up less of any increase in load

C.share an equal amount of any increase in load

D.drop an equal amount of any decrease in load

You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow direction. This indicates that the frequency of the incoming machine is

A.higher than the bus frequency

B.lower than the bus frequency

C.file same as file bus frequency but out of phase with it

D.the same as the bus frequency, and the circuit breaker may be closed at nay pointer position

A.The HVDC (high voltage DC) transmission

B.The EHV (extra-high voltage) AC transmission

C.The AC distribution

D.Generators

While paralleling two AC generators using synchronizing lamps only, both lamps will go dark when the generators are______.

A.running at the same speed

B.grounded

C.of the same polarity

D.in phase

An alternator is being paralleled with one on the line At the instant the circuit breaker is close, the frequency of the incoming alternator will normally

A.increase

B.not change

C.decrease

D.be exactly 60 hertz

Equal power factors on paralleled AC generators are maintained by an automatic ________.

A.governor control switch

B.reverse power relay

C.reverse current relay

D.voltage regulator

A.higher than the bus equency

B.lower than the bus equency

C.the same as the bus frequency but out of phase with it

D.same as the bus frequency and the circuit breaker may be closed at