更多"The voltage developed by an AC gene"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]When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is （）
A. lagging
B. leading
C. maximum
D. minimum
[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 initial voltage of self-excitation generator set up by（）
A. residual magnetism
B. voltage regulator
C. electrical current for excitation
D. the other running generator
[单项选择]The instantaneous reduction in voltage of an AC generator, resulting from an increase in load, and prior to the automatic voltage regulator correcting the situation, is called voltage （）.
A. droop
B. drop
C. dip
D. regulation
[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 frequency of an AC generator is controlled by the （）
A. rheostat
B. governor
C. exciter
D. capacitor
[单项选择]The power factor of an AC generator operating singularly is determined by the （）
A. connected load
B. prime mover speed
C. field excitation
D. generators rated voltage
[单项选择]The most common type of AC service generator found aboard ship is the stationary （）.
A. electromagnetic field, revolving armature type
B. electromagnetic field, oscillatory armature type
C. armature, oscillatory electromagnet field type
D. armature, rotating electromagnetic field type
[单项选择]The load rating of an AC generator is determined by the（）
A. internal heat it can withstand
B. load it can carry continuously
C. load it is capable of supplying
D. overload it can carry for a specified time only
[单项选择]The frequency of an AC generator is adjusted by means of the （）
A. main alternator field rheostat
B. exciter field rheostat
C. prime mover governor control
D. equalizing reactor
[单项选择]Prior to starting an AC generator prime mover, the voltage regulator cutout switch should be placed in the （）
A. manual position
B. bus neutral position
C. raise voltage position
D. transfer position
[单项选择]When securing an AC generator, you should FIRST （）.
A. open the generator circuit breaker
B. switch the voltage regulator to “manual”
C. decrease the field excitation to minimum
D. reduce the load on the unit
[单项选择]The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the （）.
A. prime mover speed
B. exciter output voltage
C. load on the alternator
D. number of poles
[单项选择]Which characteristic is a disadvantage of a controllable- pitch propeller as compared to a fixed-pitch propeller? （）
A. Slightly higher fuel consumption
B. Lack of directional control when backing
C. Inefficient at high shaft RPM
D. Some unusual handling characteristics
[单项选择]On a ship，a cabinet or space containing the controls or valves for the fixed firefighting system must be（）.
A. posted with instructions on the operation of the system
B. ventilated and equipped with explosion-proof switches
C. painted with red and black diagonal stripes
D. equipped with a battery powered source of emergency lighting
[单项选择]The test of a towing vessel’s steering gear control system includes each item EXCEPT（）.
A. a test from the alternative power supply，if installed
B. timing the movement of the rudder from hard over to hard over
C. verification that the rudder angle indicator shows the actual position of the rudder(s)
D. visual inspection of the steering linkage
