AC voltage to the armature
AC voltage to the field
DC voltage to the armature
DC voltage to the field
第1题：
A.completely loose its share of the load causing the auxiliary engine to speed up.
B.overload due to reduced voltage output and increased current
C.continue to share the active load(kw)but have high very reactive load
D.try to take all the load and so trip the main circuit breaker
第2题：
An alternator is being paralleled with one on the line At the instant the circuit breaker is close, the frequency of the incoming alternator will normally
A.increase
B.not change
C.decrease
D.be exactly 60 hertz
第3题：
此题为判断题(对，错)。
第4题：
TPIH2000报警当中“OUTPUT VOLTAGE LOW”指的是输出电压低，可能原因是发生器功功率设置太低。
第5题：
A.theFXSinterfaceallowsananalogconnectiontobedirectedatthepublicswitchedtelephonenetwork（PSTN’s）centraloffice
B.theFXSinterfaceconnectdirectlytoastandardtelephone，faxmachine，orsililardeviceandsuppliesring，voltage，anddialtone
C.theFXSinterfaceconnectdirectlytoanIPphoneandsuppliesring，voltage，anddialtone
D.theFXSinterfaceconnectdirectlytoISDNvoicechannels
第6题：
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
第7题：
The frequency of an alternator at a given r/min is determined by the _______ .
A.number of turns of wire in the armature coil
B.number of magnetic poles
C.strength of the magnets used
D.output voltage
第8题：
elephants are different from wild elephants in many aspects, including their tempers.
A) Civil B) Tame C) Cultivated D) Regulated
选B Tame 1.驯服的，顺从的
在许多方面驯服的大象是不同于野生大象，包括他们的脾气
第9题：
材料：
The field current supply in older machines comes from a lower voltage direct current generator or exciter on the same shaft as the alternator. Modern machines however are either statically excited or of the high-speed brush-less type. The exciter is required to operate to counter the effects of power factor for a given load. The power factor is a measure of the phase difference between voltage and current and is expressed as the cosine of the phase angle. With a purely resistance load the voltage and the current are in phase, giving a power factor of one. The power consumed is therefore the product of voltage and current. Inductive or capacitive loads, combined with resistance loads, produce lagging or leading power factors which have a value less than one.
The power consumed is therefore the product of current, voltage and power factor. The alternating current generator supplying a load has a voltage drop resulting from the load. When the load has a lagging power factor this voltage drop is considerable. Therefore the exciter, in maintaining the alternator voltage, must vary with load current and also the power factor. The speed change of the prime mover must also be taken into account.
问题： The word “machines” in the passage refers to _____.
A.the direct current generator
B.the alternating current generator
C.the exciter
D.the prime mover
Which of the following statements is true according to the passage ?
A.With a purely resistance load, the power factor is zero
B.Inductive loads combined with resistance loads produces leading power factors
C.Capacitive loads combined with resistance loads produces lagging power factors
D.With a purely resistance load, the phase angle is zero
When the load has a lagging power factor this voltage drop is considerable. This sentence means that _____.A.with a purely resistance load, the voltage drops too much
B.there is a considerable voltage drop in the capacitive load combined with resistance load
C.when the load is the capacitive load combined with resistance load, the voltage drops to zero
D.when the load is the inductive load combined with resistance load, the voltage drop is fairly large
The exciter must vary with: ① load current ② the power factor, ③ speed change of the prime mover.A.①
B.②
C.①②
D.①②③
请帮忙给出每个问题的正确答案和分析，谢谢！
第10题：
NVH测试中，我们目前使用的噪声振动传感器信号输入模式为（）。