单选题The sudden reduction of pressure occurring within the crankcase of a refrigeration compressor during starting causes the （）.A sudden evaporation of wax crystals in the lubricantB sudden evaporation of entrapped air in the lubricantC release of refriger

题目
单选题
The sudden reduction of pressure occurring within the crankcase of a refrigeration compressor during starting causes the （）.
A

sudden evaporation of wax crystals in the lubricant

B

sudden evaporation of entrapped air in the lubricant

C

release of refrigerant from the oil/refrigerant mixture

D

release of dissolved lubricant from the refrigerant

相似考题

1.A diesel engine experiences a sudden loss in speed, accompanied by black exhaust smoke, with the fuel rack at maximum, and speed remaining below normal .the probable ___.A.engine overloadB.leaky valvesC.stuck or broken piston ringsD.low air injection pressure

2.If a heavy sea strikes the rudder, the shock is transmitted through ___ to the rams, this cause a sudden increase in oil pressure in one of the cylinders.A.the control rodB.the hunting gearC.the floating ringD.the tiller arm

3.Wear occurring at the tips of the reduction gear teeth is usually the result of ______.A.surface fatigueB.fretting corrosionC.heavy overloadingD.gear misalignment

4.Before performing any maintenance on a hydraulic system storing energy in an accumulator, you shouldA.pressurize the system to test for leaksB.bleed off all pressure within the systemC.operate the machine until it reaches normal temperatureD.disconnect the pump pressure control switch

更多“The sudden reduction of pressure occurring within the crankc”相关问题

  • 第1题：

    Restrictions occurring in the small orifices(孔) of pneumatic control system components can be caused by ______.

    A.moisture in the compressed air supply

    B.excessive dryness in the compressed air supply

    C.pressure surging in the compressed air receiver

    D.insufficient lubrication of the system components


    正确答案：A

  • 第2题：

    单选题
    Condensate formed within the first-effect tube nest of a double-effect,low pressure evaporator, is removed by a （）.
    A

    series of baffles

    B

    crossover pipe

    C

    condensate separator

    D

    drain pump


    正确答案： A
    解析： 暂无解析

  • 第3题：

    名词解释题
    撞击声压级改善量reduction of impact sound pressure level

    正确答案： 在楼板面层铺设之前和之后接收室内的平均声压级差值，以dB表示。
    解析： 暂无解析

  • 第4题：

    单选题
    Your facsimile prognostic chart indicates that you will cross the cold front of a low pressure system in about 24 hours.You should（）.
    A

    Expect to see cirrus clouds followed by altostratus and nimbostratus clouds

    B

    Alter course to remain in the navigable semicircle

    C

    Prepare for gusty winds，thunderstorms，and a sudden wind shift

    D

    Expect clear weather，with steady winds and pressure，until the front passes


    正确答案： A
    解析： 暂无解析

  • 第5题：

    单选题
    A sudden drop in diesel engine cylinder compression pressure can be caused by（）
    A

    a leaking fuel injector nozzle

    B

    a clogged air filter

    C

    excessively early fuel injection

    D

    malfunctioning valves


    正确答案： A
    解析： 暂无解析

  • 第6题：

    单选题
    A probable cause for a turbo generator tripping out on overspeed is a sudden（）
    A

    loss of field excitation

    B

    total loss of load

    C

    large increase in load

    D

    loss of steam pressure


    正确答案： C
    解析： 暂无解析

  • 第7题：

    单选题
    Air trapped in the hydraulic fluid of a steering system may be indicated by（）
    A

    the steering pumps overspeeding

    B

    a jammed open relief vale

    C

    a constantly occurring improper rudder response

    D

    excessive ram pressure


    正确答案： D
    解析： 暂无解析

  • 第8题：

    单选题
    One cause of high head pressure occurring in a refrigeration system can be （）.
    A

    insufficient cooling water flow to the condenser

    B

    a low refrigerant charge in the system

    C

    the liquid valve is open too much

    D

    high evaporator superheat


    正确答案： A
    解析： 暂无解析

  • 第9题：

    单选题
    The pressure in an operating diesel engine cylinder continues to rise for a short period after the piston passes top dead center as a result of the （）
    A

    expansion of the combustion gases

    B

    exhaust and intake valves just closing

    C

    maximum compression is just being attained

    D

    fuel injection occurring at that point and combustion begins


    正确答案： A
    解析： 暂无解析

  • 第10题：

    单选题
    Wear occurring at the tips of the reduction gear teeth is usually the result of （）.
    A

    surface fatigue

    B

    fretting corrosion

    C

    heavy overloading

    D

    gear misalignment


    正确答案： D
    解析： 暂无解析

  • 第11题：

    单选题
    A sudden drop in compression pressure in one cylinder of a diesel engine can be caused by（）
    A

    a leaking fuel injector nozzle

    B

    a clogged air filter

    C

    excessively early fuel injection

    D

    malfunctioning valves


    正确答案： D
    解析： 暂无解析

  • 第12题：

    单选题
    Damage caused by lighting，a storm，or a sudden gust of wind may be within the exception of （）.
    A

    act of God

    B

    the Queen's enemies

    C

    inherent vice in the goods

    D

    the negligence of the owner of the goods


    正确答案： C
    解析： 暂无解析

  • 第13题：

    Damage caused by lighting，a storm，or a sudden gust of wind may be within the exception of ______.

    A.act of God

    B.the Queen's enemies

    C.inherent vice in the goods

    D.the negligence of the owner of the goods


    正确答案：A

  • 第14题：

    单选题
    The text supplies information to answer which of the following questions?
    A

    How does the reduction of space affect intragroup aggression among monkeys in an experimental setting?

    B

    Do family units within a monkey social group compete with other family units for food?

    C

    What are the mechanisms by which the social order of an established group of monkeys controls aggression within that group?

    D

    How do monkeys engaged in aggression with other monkeys signal submission?


    正确答案： A
    解析：
    细节理解题。文章第二段第二句提到the motivating force of competition for incentives began to be doubted when experiments like Southwick’s on the reduction of space…，即实验的一个重点是看空间的减少对猴群之间的竞争的影响，随后三、四段论述了在一个有组织的群体内引入一个入侵者后的猴群的表现，因此A项“在实验背景下，空间的减少是如何影响猴群内的成员关系的”符合文意。

  • 第15题：

    单选题
    A diesel engine experiences a sudden loss in speed, accompanied by black exhaust smoke, with the fuel rack at maximum, and speed remaining below normal the probable（）
    A

    engine overload

    B

    leaky valves

    C

    stuck or broken piston rings

    D

    low air injection pressure


    正确答案： A
    解析： 暂无解析

  • 第16题：

    单选题
    The domestic fresh water pump starters are controlled by pressure switches which operate when the pressure in the tank varies within predetermined limits as water is drawn offThe word “which” means （）.
    A

    starters

    B

    pressure switches

    C

    pressure

    D

    water


    正确答案： B
    解析： 暂无解析

  • 第17题：

    单选题
    When a sudden increase in steam demand occurs from the boiler, the water level in the drum at the higher pressure will（）
    A

    rise quickly

    B

    rise slowly

    C

    drop quickly

    D

    drop slowly


    正确答案： B
    解析： 暂无解析

  • 第18题：

    单选题
    When a sudden increase in steam demand comes to normal, the drum pressure will and water level in the drum will（）.
    A

    rise, rise also

    B

    rise, drop

    C

    drop, rise

    D

    drop, drop also


    正确答案： D
    解析： 暂无解析

  • 第19题：

    单选题
    If a heavy sea strikes the rudder, the shock is transmitted through （） to the rams, this cause a sudden increase in oil pressure in one of the cylinders.
    A

    the control rod

    B

    the hunting gear

    C

    the floating ring

    D

    the tiller arm


    正确答案： D
    解析： 暂无解析

  • 第20题：

    单选题
    Critical speeds occurring within the operating speed range of a main propulsion diesel engine may be changed, or have their damaging effects reduced by a/an （）
    A

    engine support vibration isolator

    B

    detuner or viscous fluid damper

    C

    lightened crankshaft flywheel

    D

    spherically seated crankshaft bearing


    正确答案： B
    解析： 暂无解析

  • 第21题：

    单选题
    To guarantee that a reduction gear bearing is receiving proper oil supply, you should check the （）
    A

    lube oil temperature at the cooler outlet

    B

    lube oil strainer magnets bearing

    C

    lube oil temperature

    D

    lube oil pressure to the bearing


    正确答案： A
    解析： 暂无解析

  • 第22题：

    单选题
    To maintain the down stream pressure within defined limits over a range of flow and despite any changes in supply pressure, （） is fitted.
    A

    a check valve

    B

    a gate valve

    C

    a pressure reducing valve

    D

    a quick closing valve


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    Excessively low air pressure occurring in the intercooler of a reciprocating air compressor is caused by（）.
    A

    leaky discharge valves on the LP cylinder

    B

    leaky discharge valves on the HP cylinder

    C

    insufficient intercooler cooling

    D

    low ambient air pressure


    正确答案： C
    解析： 暂无解析

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