更多"The initial voltage of self-excitat"的相关试题:
[单项选择]A constant output voltage from an AC generator is maintained by the （）.
A. prime mover governor
B. exciter generator
C. voltage regulator
D. reverse power relay
[单项选择]The voltage developed by an AC generator is controlled by varying the （）
A. speed of the prime mover
B. AC excitation to the field
C. DC excitation to the field
D. DC excitation of the voltage regulator
[单项选择]The voltage output of an AC generator is controlled by（）
A. varying the DC exciter voltage
B. varying the reluctance of the air gap
C. regulating the speed of the prime mover
D. shorting out part of the armature windings
[单项选择]The effects of free surface on a vessel’s initial stability do NOT depend upon the（）.
A. volume of displacement of the vessel
B. dimensions of the surface of the liquid
C. amount of liquid in slack tanks
D. specific gravity of the liquid in the tank
[单项选择]An emergency diesel generator should automatically shut down in the event of （）
A. dangerous over-speeding
B. a loss of lube oil pressure
C. activation of the fixed CO2 system for the emergency generator space
D. all of the above
[单项选择]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
[单项选择]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 （）.
A. is small
B. may be neglected
C. is useful
D. is considerable
[单项选择]Generator brushes are staggered to（）
A. reduce current pulsations
B. reduce brush chatter
C. prevent uneven commutator wear
D. allow greater power generation
[单项选择]Each emergency generator on a mobile offshore drilling unit，when tested，must be run under a full load for at least（）.
A. one hour
B. two hours
C. ten hours
D. four hours
[单项选择]A generator is prevented from becoming motorized by the use of a/an （）.
A. over-speed trip
B. reverse power relay
C. back pressure trip
D. governor controls
[单项选择]Emergency generator is installed on board mainly to （）
A. connect to the busbar when the load increasing
B. supply power specially to charging panel
C. be put into operation during the ship arriving at or leaving port
D. ensure the power supply to critical equipment after the main switchboard out of power
[单项选择]The emergency generator or emergency battery is connected to（） on most large ships.
A. distribution boards
B. section boards
C. emergency switch boards
D. main switch boards
[单项选择]Standby or emergency diesel generator day tanks should always be kept full to reduce the possibility of（）
A. sediment contamination
B. fuel filter clogging
C. moisture formation
D. inadequate transfer pump suction head
[单项选择]A diesel driven emergency generator is prevented from being paralleled with the ships service generators by （）
A. an electrical interlock system
B. an automatic paralleling trip switch
C. the synchronizing oscilloscope
D. the reverse current relay
[单项选择]For most diesel propulsion and generator engines, the over-speed trip device will stop the engine by （）
A. moving the governor control to stop
B. shutting off the lubricating oil supply
C. tripping the governor emergency stop lever
D. shutting off the fuel supply
[名词解释]额定电压（rated voltage）
[名词解释]标称电压（nominal voltage）
[名词解释]接触电压（touch voltage）
