VACUUM GENERATOR的工作条件（）A、在地面或空中低于16000英尺B、仅在地面C、仅在空中低于16000英尺D、飞机高度高于16000FT
VACUUM GENERATOR的工作条件（）
- A、在地面或空中低于16000英尺
- B、仅在地面
- C、仅在空中低于16000英尺
- D、飞机高度高于16000FT
相关考题：
In a modern three-phase A.C. synchronous brushes generator, the excitation winding is on the rotor. That means .A.The generator need not excitation.B.The winding on the rotor is for inputting excitation current.C.There are three phase windings on the rotor.D.The generator has no brushes.
The frequency of an AC generator is controlled by the ___.A.rheostatB.governorC.exciterD.capacitor
单选题The purpose of DC generator brushes is to （）.Aneutralize armature reactionBconduct electric current to an outside circuitCconvert DC current to AC currentDprovide excitation to a DC generator
单选题A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an （）ArotorBstatorCexciterDarmature
单选题When securing an AC generator, you should FIRST （）.Aopen the generator circuit breakerBswitch the voltage regulator to “manual”Cdecrease the field excitation to minimumDreduce the load on the unit
单选题The frequency of an AC generator is controlled by the （）ArheostatBgovernorCexciterDcapacitor
单选题An emergency diesel generator should automatically shut down in the event of （）Adangerous over-speedingBa loss of lube oil pressureCactivation of the fixed CO2 system for the emergency generator spaceDall of the above
单选题The crankcase of many diesel engines are kept under a slight vacuum by the （）.Ascavenging action of the pistonBpiston type vacuum pump taking suction off a differential manometerCgland exhausting manometerDcrankcase exhaust fan
单选题Which one of the followings might not be employed to create vacuum for flash type evaporator? （）Ahigh-pressure steam-driven air-ejectorBmotor-driven vacuum pumpCwater-motivated air eductorDcentrifuge pump
单选题A diesel generator has just been paralleled with an AC turbo-generator, but the load can not be properly divided.This could be caused by（）Aan incorrect diesel generator governor speed droop adjustmentBa faulty reverse power relay within the main circuit breaker assemblyCunsynchronized isochronous load distribution adjustmentsDa different speed setting on each unit
单选题The initial voltage of self-excitation generator set up by（）Aresidual magnetismBvoltage regulatorCelectrical current for excitationDthe other running generator
单选题Which of the following should be the FIRST step in removing a generator from parallel operation?（）ATrip the generator off the switchboardBTurn off all electrical equipmentCRemove the load from the off going generatorDIncrease the cycles of the generator staying on the line
单选题A vacuum is initially created in a flash type distilling plant by（）.Athe flashing of the feed waterBthe condensation of the saltwater feedCair ejectors, eductors, or a separate vacuum pumpDcondensation of the distillate
单选题A vacuum is initially established in the first and second stages of a low pressure evaporator by the use of （）Avacuum drag from the auxiliary condensate systemBindividual vacuum pumpsCa single non-condensing air ejectorDa two stage air ejector
单选题In a modern three-phase A-Csynchronous brushless generator, the excitation winding is on the rotorThat means （）.AThe generator needs not excitationBThe winding on the rotor is for inputting excitation currentCThere are three phase windings on the rotorDThe generator has brushes
单选题What is TRUE of pressure/vacuum valves? （）AThey are designed to provide for the flow of small volumes of tank atmospheres caused by thermal variations in a cargo tankBThey should operate in advance of the pressure/vacuum breakersCThey should be kept in good working order by regular inspection and cleaningDAll of the above