单选题Voltage generated by most AC generators is fed from the machine to the bus by means of().Abrushes on a commutatorBbrushes on slip ringsCslip rings on a commutatorDdirect connections from the stator
单选题
Voltage generated by most AC generators is fed from the machine to the bus by means of().
A
brushes on a commutator
B
brushes on slip rings
C
slip rings on a commutator
D
direct connections from the stator
参考解析
解析:
暂无解析
相关考题:
( ) can provide an asynchronous link between two ac electric power system with different nominal frequencies. A.The HVDC (high voltage DC) transmissionB.The EHV (extra-high voltage) AC transmissionC.The AC distributionD.Generators
The upper piston rings m large, slow-speed, two-stroke/cycle diesel engines are most effectively lubricated by oil ____.A.fed from mechanical lubricatorsB.thrown off from the main bearingsC.supplied from wick fed drip lubricatorsD.flow from a centrifugal or banjo oiler
A technician suspects the AC voltage into a PC power supply is bad. Which of the following toolswould MOST likely be used to confirm the diagnosis?() A. MultimeterB. OscilloscopeC. Cable testerD. Power supply tester
Equal power factors on paralleled AC generators are maintained by an automatic ________.A.governor control switchB.reverse power relayC.reverse current relayD.voltage regulator
While paralleling two AC generators using synchronizing lamps only, both lamps will go dark when the generators are______.A.running at the same speedB.groundedC.of the same polarityD.in phase
The ASBR-summary LSA is:().A、Generated by the ASBR and describes reachability to itselfB、Generated by the ASBR and describes reachabilty to the ABRC、Generated by the ABR and describes reachabilty to the ASBR for routers in a different area from the ASBRD、Generated by the ABR and describes reachabilty to the ASBR for routers in the same area with the ASBR
A military member has just returned to the United States from Europe and reports their personaldesktop computer does not work. Which of the following is the MOST logical solution to thisproblem?()A、The computer is unable to work in the US because of EU licensing arrangementsB、The power supply needs to be replaced with one rated for 110 wattsC、The power supply needs a power inverter to handle the change in cyclesD、The power supply voltage needs to be switched to 110 from 220
A technician suspects the AC voltage into a PC power supply is bad. Which of the following toolswould MOST likely be used to confirm the diagnosis?()A、MultimeterB、OscilloscopeC、Cable testerD、Power supply tester
单选题()on board ship are used to control and distribute the electrical energy generated by generators.AGovernorsBAlternatorsCBlackboardsDSwitchboards
单选题The instantaneous reduction in voltage of an AC generator, resulting from an increase in load, and prior to the automatic voltage regulator correcting the situation, is called voltage ().AdroopBdropCdipDregulation
单选题Which is a function of the voltage regulators used with AC generators?()ATo cut out generators when they are no longer requiredBTo cut in additional generators automatically as requiredCTo divide the KW load equally between generators operating in parallelDTo divide reactive current between generators operating in parallel
单选题Generators should have an excitation/voltage regulation system which will enable them to share the steady state reactive load () no machine exceeds its proportional share of reactive load by more than 10% of the rated reactive load of the largest generator.AwhenBso asCsuch thatDthough
单选题AC voltmeters are generally calibrated to read the ()Ainstantaneous voltageBaverage voltageCRMS voltageDpeak voltage
单选题While paralleling two AC generators using synchronizing lamps only, both lamps will go dark when the generators are ().Arunning at the same speedBgroundedCof the same polarityDin phase
单选题Prior to starting an AC generator prime mover, the voltage regulator cutout switch should be placed in the ()Amanual positionBbus neutral positionCraise voltage positionDtransfer position
单选题The alternating current generator supplying a load has a voltage drop resulted from the loadWhen the load has a lagging power factor this voltage drop ().Ais smallBmay be neglectedCis usefulDis considerable
单选题The most inefficient method of voltage reduction from the stand point of power loss, is a/an ()Acapacitor in series with the loadBinductor in series with the loadCcapacitor and inductor in series with the loadDresistor in series with the load
单选题A military member has just returned to the United States from Europe and reports their personaldesktop computer does not work. Which of the following is the MOST logical solution to thisproblem?()AThe computer is unable to work in the US because of EU licensing arrangementsBThe power supply needs to be replaced with one rated for 110 wattsCThe power supply needs a power inverter to handle the change in cyclesDThe power supply voltage needs to be switched to 110 from 220
单选题When paralleled, AC generators must have the same ()AfrequencyBnumber of phasesCphase rotationDAll of the above
单选题When two DC generators operate in parallel, they are protected against motorizing by()Ablow out coilsBgovernor relayCunder voltage tripsDreverse current trips
单选题If two AC generators are operated in parallel, the load is distributed evenly by()Aa rheostatBa balancing coilCchanging field excitationDadjusting the governor settings
单选题The most common source of excitation for synchronous motors is a/an ().Alow voltage batteryBmotor attenuator setCDC exciter generatorDAC supply
单选题AC and DC generators are similar in that they ()Aboth generate alternating voltagesBboth rectify the voltage before deliveryCare constructed at the same physical size for the same kilowatt ratingDboth supply three-phase power
单选题The number of cycles per second occurring in AC voltage is known as the ()Aphase angleBfrequencyCwave formDhalf mode
单选题When paralleling two AC generators, the frequency of the machine coming on-line, immediately prior to closing its breaker, should be ()Aslightly less than the oncoming generator frequencyBthe same as the bus frequencyCslightly greater than the bus frequencyDthe same as the bus voltage
单选题The voltage developed by an AC generator is controlled by varying the ()Aspeed of the prime moverBAC excitation to the fieldCDC excitation to the fieldDDC excitation of the voltage regulator
单选题A constant output voltage from an AC generator is maintained by the ().Aprime mover governorBexciter generatorCvoltage regulatorDreverse power relay