单选题The DC excitation to the field of brushless synchronous is generally produced by （）Aan exciter driven by the same shaft with the generatorBan exciter driven by external prime moverCgenerator itselfDeither A and B
单选题
The DC excitation to the field of brushless synchronous is generally produced by （）
A
an exciter driven by the same shaft with the generator
B
an exciter driven by external prime mover
C
generator itself
D
either A and B
参考解析
解析：
暂无解析
相关考题：
In an AC.synchronous motor electric propulsion plant,propeller speed is controlled by() A.prime mover speedB.number of energized main motor polesC.propulsion generator field strengthD.electric coupling field strength
An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard as aA.magnetic amplifierB.ship's service alternatorC.three-wire DC generatorD.saturable core reactor
The division of kilowatt load between two paralleled alternators is determined by theA.amount of field excitation of the leading machineB.load-speed characteristics of the governorsC.amount of field excitation to the lagging machineD.type of alternator
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.
Brushless generators are designed to operate without the use of_____.A.brushesB.slip ringsC.commutatorsD.all of the above
jim has created a field hint for the address field. Users tell him this text disappears when they click in the address field. which one of the following is most likely reason?（）A、 the address field is computed B、 jim should have used a text popup C、 jim stored the field hint in the database D、 field hint only display when the user has not clicked in the field （field hint）
SONET全称为（）A、synchronous optimized networkB、synchronous optical networkC、synthesis optimized networkD、synthesis optical network
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An AC synchronous transmission type remote steering control system consists of a （）.Atransmitter at the steering station and a receiver at the steering engineBreversible motor at the steering station geared to the steering pumpsCsmall induction motor on the bridge which controls the redder through pulleysDvariable displacement hydraulic pump driven by a reversible DC motor
单选题jim has created a field hint for the address field. Users tell him this text disappears when they click in the address field. which one of the following is most likely reason?（）A the address field is computed B jim should have used a text popup C jim stored the field hint in the database D field hint only display when the user has not clicked in the field （field hint）
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An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a （）.Amagnetic amplifierBship’s service alternatorCthree-wire DC generatorDsaturable core reactor
单选题Adam Smith was a professor of philosophy, a commissioner of customs, and founded the field of modern economics.Aa commissioner of customs, and founded the field of modem economicsBworked as commissioner of customs, and founded the field of modern economicsCa commissioner of customs, and the founder of the field of modern economicsDcommissioned customs, and was the founder of the field of modern economicsEa commissioner of customs, and was the founder of the field of modem economics
单选题If a DC motor runs hot, the cause may be （）Ahigh mica conditionBlow ambient temperatureCclogged ventilation ductsDan open in the shunt field
单选题Brushless generators are designed to operate without the use of（）.AbrushesBslip ringsCcommutatorsDall of the above
单选题Self-excited a-cgenerator with "error operated" voltage control systems draw the full excitation power for the machine terminalsThis dispenses with the current transformers, reactors and capacitors necessary for accurate compounding, but renders the excitation system vulnerable to variations in its output voltageWhich of the following is correct about the generator mentioned according to the sentences above （）.AIt consumes no excitation powerBIt has current transformersCComponents are needed for accurate compoundingDIts excitation system is vulnerable to voltage variations
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DC generators are classified according to the manner in which（）Athey are usedBthe field windings are connected to the loadCthe armature circuit is connected to the loadDthe field windings are connected to the armature circuit
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The division of kilowatt load between two paralleled alternators is determined by the （）Aamount of field excitation of the leading machineBload-speed characteristics of the governorsCamount of field excitation to the lagging machineDtype of alternator