网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
The function of damper windings in a synchronous motor is to （）.
A
eliminate slippage
B
provide excitation
C
provide starting torque
D
increase efficiency
参考答案
参考解析
解析：
暂无解析
更多 “单选题The function of damper windings in a synchronous motor is to （）.A eliminate slippageB provide excitationC provide starting torqueD increase efficiency” 相关考题
考题
The disadvantage of the non－synchronous motor is that it requiresoand it produces a low starting－torque
A.much initial currentB.direct currentC.little initial currentD.constant current
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
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.
考题
The primary function of an electric motor is to ______.A.develop torqueB.generate high voltagesC.produce a magnetic fieldD.generate high electrical resistance
考题
The ventilation system of your ship has fire dampers restrained by fusible links. Which statement is TRUE?A.Fusible links must be replaced if a damper is activatedB.Fusible links are tested by applying a source of heat to themC.Fusible links must be replaced at every inspection for certificationD.A fusible link will automatically open after a fire is extinguished and reset the damper
考题
Under no circumstances______without looking carefully to the rear.
A.should one back up a motor vehicle
B.a motor vehicle should back up
C.one should back up a motor vehicle
D.should back up a motor vehicle
考题
Which IBM System Storage DS8000 copy function provides a three-site or three-copy solutionusing both synchronous and asynchronous replication?（）A、FlashCopyB、Metro/Global MirrorC、Metro MirrorD、Global Mirror
考题
SONET全称为（）A、synchronous optimized networkB、synchronous optical networkC、synthesis optimized networkD、synthesis optical network
考题
单选题Some large A-Cmotors are equipped with heatersThese could be （） (1)resistance heaters bolted directly to the frame (2)low voltage windings embedded in the motor windingsA
(1) onlyB
(2) onlyC
either (1) or (2)D
neither (1) or (2)
考题
单选题The main purpose of an electric space heater installed in a large AC generator is to （）A
prevent the windings from becoming brittleB
prevent moisture from condensing in the windings during shutdownC
prevent acidic pitting of the slip ringsD
keep the lube oil warm for quick starting
考题
单选题A fire, occurring in the windings, of an overloaded electrical motor, is considered a （）.A
class A fireB
class B fireC
class C fireD
class D fire
考题
单选题操作完后，关掉电动机。（）A
After operation, start the electric motor.B
Before operation, stop the electric motor.C
Before operation, start the electric motor.D
After operation, stop the electric motor.
考题
单选题An AC synchronous transmission type remote steering control system consists of a （）.A
transmitter at the steering station and a receiver at the steering engineB
reversible motor at the steering station geared to the steering pumpsC
small induction motor on the bridge which controls the redder through pulleysD
variable displacement hydraulic pump driven by a reversible DC motor
考题
单选题The primary function of an electric motor is to （）A
develop torqueB
generate high voltagesC
produce a magnetic fieldD
generate high electrical resistance
考题
单选题“380V/220V Y/△” noted on the nameplate of a non-synchronous motor means that（）A
the armature terminals of the motor should be connected in star formation when voltage of power supply is 380B
the armature terminals of the motor should be connected in star formation when voltage of power supply is 220C
both A and B are correctD
the armature terminals of the motor should be connected in reverse ways of A and B
考题
单选题The function of synchronous compensating machine is to（）A
improve power factorB
reduce voltage oscillationC
increase the insulation of circuitsD
eliminate regenerated magnetic fields
考题
单选题A viscous damper, as used on a marine diesel, is a sealed precision built device which dampens the torsional vibrations in the （）.A
camshaftB
flywheelC
crankshaftD
thrust shaft
考题
单选题The nameplate of an AC non-synchronous motor shows that running speed is 1460r/minfrequency 50HzYou can infer that the number of magnetic poles is（）A
2B
4C
6D
8
考题
单选题DC generators are classified according to the manner in which（）A
they are usedB
the field windings are connected to the loadC
the armature circuit is connected to the loadD
the field windings are connected to the armature circuit
考题
单选题What type of electric motor is most commonly used on board ship?（）A
non-synchronous electric motorB
synchronous electric motorC
fully enclosed electric motorD
watertight electric motor
考题
单选题The ventilation system of your ship has fire dampers restrained by fusible links. Which statement is TRUE? （）A
Fusible links must be replaced if a damper is activatedB
Fusible links are tested by applying a source of heat to themC
Fusible links must be replaced at every inspection for certificationD
A fusible link will automatically open after a fire is extinguished and reset the damper
热门标签
最新试卷