The power factor of an AC generator operating singularly is determined by the （）

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• The power factor at which a paralleled AC generator operates is usually adjusted by the （）.

  A . connected load B . prime mover speed C . field excitation D . generators rated voltage

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• The most inefficient method of voltage reduction from the stand point of power loss, is a/an （）

  A . capacitor in series with the load B . inductor in series with the load C . capacitor and inductor in series with the load D . resistor in series with the load

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• 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

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• The holding power of an anchor increases when the（）.

  A . amount of chain lying along the bottom increases B . length of the catenary is reduced C . mooring line tension is increased D . amount of chain lying along the bottom decrease

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• Why is it desirable to operate paralleled AC generators at the same power factor?（）

  A . Circulating currents are kept to a minimum B . Field excitation losses are kept to a minimum C . Generator rotors will have a lesser tendency to hunt D . Because a power factor increase will decrease kilowatt output

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• The energy consumed by an AC motor, as strictly reactive power, is （）

  A . used to do mechanical work B . used to establish the magnetic field of the motor C . lost as heat generated by the windings D . lost in doing work to turn the motor itself

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• With a purely （） load the voltage and current are in phase, giving a power factor of one.

  A . inductive B . resistance C . combined D . capacitate

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• What is the holding power ratio of an anchor? （）

  A . Maximum mooring line tension divided by the anchor's weight in air B . Anchor's weight in air divided by the maximum mooring line tension C . Preloading tension divided by the anchor's weight in air D . Operating tension divided by the anchor's weight in air

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• Which of the following types of motors is often designed for use in correcting power factor?（）

  A . Polyphase B . Wound-rotor C . Induction D . Synchronou

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• Fuel oil is thought to be one of the main factors （） the operation and maintenance of an engine.

  A . have nothing to do with B . having nothing to do with C . have much to do with D . having much to do with

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• The holding power of an anchor at a given scope of cable increases when the（）.

  A . amount of chain lying along the bottom increases B . length of the catenary is reduced C . mooring line tension is increased D . amount of chain lying along the bottom decrease

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• The indicated power of an engine can be obtained by taking the （）.

  A . precautions B . rpm C . indicator cards D . B and C

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• In an alternating current electrical system, a low system power factor is a direct sign of （）

  A . wasted energy B . efficient operation C . a short in the exciter field windings D . an excessive number of minor system ground

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• 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

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• During a review of environmental requirements before ordering an IBM System z9 server and IBM System Storage DS8700， the customer states that the available power is 220 volts AC.  Which feature should be included with the DS8700 order（）  

  A . Low Voltage B . High Voltage C . Remote System z Power Control D . Battery Assembly

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• The holding power of an anchor is the（）.

  A . maximum sustained vertical load an anchor will resist before dragging B . maximum sustained horizontal load an anchor will resist before dragging C . maximum sustained vertical load an anchor will resist before the mooring line breaks D . maximum sustained horizontal load an anchor will resist before the mooring line break

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• The most important factor in engine performance is the actual power output at the end of the crankshaft available for doing workThis is known as （）.

  A . indicated horsepower B . brake horsepower C . net horsepower D . friction horsepower

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• What are three factors that limit the maximum distance of an amplified optical signal without regeneration？ （）

  A .  fiber dispersion B .  signal attenuation C .  transmitter power D .  amplifier bandwidth E .  receiver dispersion tolerance

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• A three-phase alternator operates at 450 volts with a power factor of 0~8.If the ammeter indicates 250 amperes, what should be the KW meter reading （）.

  A . 90~0 kw B . 127~27 kw C . 155~70 kw D . 194~85 kw

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• Which of the following factor is NOT an element of a cause-and-effect relationship?

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• The importance of irradiation as an etiologic factor in the _____ of human thyroid carcinoma is well documented.

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• With a purely resistance load the voltage and current are in phase, giving a power factor of _____.

  A.one B.less than one C.more than one D.negative one

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• The power factor of an AC generator operating singularly is determined by the_______ .

  A.connected load B.prime mover speed C.field excitation D.generator's rated voltage

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• 决定一个厂商垄断势力大小的因素有哪些？简要解释每种因素。What factors determine the amount of monopoly power an individual firm is likely to have？ Explain each one briefly.

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