更多"The main generators are connected t"的相关试题:
[单项选择]Electric generators can be protected against overload（）.
A. With switches
B. With a governor on the engine
C. With fuses or circuit breakers
D. By using heavy wire
[单项选择]While paralleling two AC generators using synchronizing lamps only, both lamps will go dark when the generators are （）.
A. running at the same speed
B. grounded
C. of the same polarity
D. in phase
[单项选择]Brushless generators are designed to operate without the use of（）.
A. brushes
B. slip rings
C. commutators
D. all of the above
[单项选择]When the prime movers of two paralleled generators are equipped with mechanical- hydraulic governors, and are operating within their designed range, the unit with the least amount of speed droop will （）.
A. pick up more of any increase in load
B. pick up less of any increase in load
C. share an equal amount of any increase in load
D. drop an equal amount of any decrease in load
[单项选择]When paralleling two AC generators, the frequency of the machine coming on-line, immediately prior to closing its breaker, should be （）
A. slightly less than the oncoming generator frequency
B. the same as the bus frequency
C. slightly greater than the bus frequency
D. the same as the bus voltage
[单项选择]DC generators are classified according to the manner in which（）
A. they are used
B. the field windings are connected to the load
C. the armature circuit is connected to the load
D. the field windings are connected to the armature circuit
[单项选择]The operating diesel generators will have their exhaust temperatures, cooling water and lubricating oil temperatures and pressures （） in much the same way as for the main engine.
A. to be kept
B. logged
C. changed
D. has remained
[单项选择]Equal power factors on paralleled AC generators are maintained by an automatic （）.
A. voltage regulator
B. reverse power relay
C. reverse current relay
D. governor control switch
[单项选择]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.
A. when
B. so as
C. such that
D. though
[单项选择]Starting motors，generators，and other spark producing devices should be mounted as high above the bilges as possible to（）.
A. keep them dry when the bilges are full of water
B. keep them cool when the vessel is underway
C. make them more accessible for repairs
D. prevent accidental ignition of any gasoline vapors that may have accumulated in the bilges
[单项选择]When paralleled, AC generators must have the same （）
A. frequency
B. number of phases
C. phase rotation
D. All of the above
[单项选择]You are attempting to parallel two AC generators, and the syncope pointer is revolving in the fast directionThis indicates that the frequency of the incoming machine is （）.
A. higher than the bus frequency
B. lower than the bus frequency
C. the same as the bus frequency but out of phase with it
D. the same as the bus frequency and the circuit breaker may be closed at any pointer position
[单项选择]You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow directionThis indicates that the frequency of the incoming machine is （）.
A. higher than the bus frequency
B. lower than the bus freouencv
C. the same as the bus frequency but out of phase with it
D. the same as the bus frequency, and the circuit breaker may be closed at any pointer position
[单项选择]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
[单项选择]The generators on your rig have shut down，leaving you without navigation lights. Which emergency signal would you transmit over the VHF radio to alert vessels in the area of your predicament? （）
A. Mayday，Mayday，Mayday
B. Pan，Pan，Pan
C. Security，Security，Security
D. Lights out，Lights out，Lights out
[单项选择]When two DC generators operate in parallel, they are protected against motorizing by（）
A. blow out coils
B. governor relay
C. under voltage trips
D. reverse current trips
[单项选择]When two AC generators are being paralleled, the breaker should be closed with the synchroscope pointer mating in the （）
A. "slow" direction, just before the 12 o'clock position
B. "fast" direction, just after the 12 o'clock position
C. "fast" direction, just before the 12 o'clock position
D. "slow" direction, just after the 12 o'clock position
[单项选择]If two AC generators are to be operated in parallel, the load is distributed evenly by（）
A. means of rheostat the governor settings
B. a balance coil excitation
C. adjusting the governor settings
D. changing excitation
