The amount of fluid delivered by a positive displacement pump can be regulated by _____.A.throttling the pressure lineB.changing the speed of the driving rotorC.either A or BD.None of the above is tree

题目

The amount of fluid delivered by a positive displacement pump can be regulated by _____.

A.throttling the pressure line

B.changing the speed of the driving rotor

C.either A or B

D.None of the above is tree

相似考题

1.Overheating of the hydraulic fluid in an electro-hydraulic anchor windlass can result from a/an( ).A.overload on the pump motorB.low fluid level in the reservoirC.low fluid viscosity around the shaft sealD.high oil level in the sump

2.If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.A.excessive pump speedB.excessive suction headC.worn wearing ringsD.gross pump misalignment

3.The amount of fuel delivered by a helical plunger fuel injection pump is controlled by ______.A.varying the pump discharge pressureB.varying the pump return pressureC.rotation of the pump plungerD.rotation of the pump barrel

4.The pressure of a liquid leaving the pump can be referred to as the ______.A.total headB.discharge headC.net positive suction headD.suction head

更多“The amount of fluid delivered by a positive displacement pump can be regulated by _____.A.throttling the pressure lineB.changing the speed of the driving rotorC.either A or BD.None of the above is tree”相关问题

  • 第1题：

    单选题
    The output volume of a positive fixed displacement pump can be changed only by （）.
    A

    changing the angle of the tilting plate

    B

    changing the speed of the pump

    C

    moving the slide block and rotor

    D

    moving the shaft trunnion block


    正确答案： B
    解析： 暂无解析

  • 第2题：

    单选题
    A positive displacement pump is that where the volume of the pump chamber is alternately （） to draw the liquid in and then （） to force the liquid out.
    A

    increased；decreased

    B

    decreased；increased

    C

    decreased；decreased

    D

    increased；increased


    正确答案： A
    解析： 暂无解析

  • 第3题：

    单选题
    Gear pumps are （） because they discharge a near constant amount of liquid regardless of pressure.
    A

    negative displacement type

    B

    turbine type

    C

    positive displacement type

    D

    mixed-flow type


    正确答案： C
    解析： 暂无解析

  • 第4题：

    单选题
    Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.
    A

    depending on

    B

    in relative to

    C

    regardless of

    D

    because of


    正确答案： C
    解析： 暂无解析

  • 第5题：

    单选题
    The pump has a constant stroke and the amount of fuel delivered is regulated by rotating （） which has a specially arranged helical groove cut into it.
    A

    the pump cylinder

    B

    the pump cam

    C

    the pump plunger

    D

    the pump miler


    正确答案： C
    解析： 暂无解析

  • 第6题：

    单选题
    Which of the following statements is/are true regarding hydraulic pumps in general? （）
    A

    Variable volumes can be obtained with gear pumps only by variation of the pump drive speed

    B

    A radial piston pump houses sliding pistons in a stationary cylinder block through which passes a rotating pintle or ported shaft

    C

    The amount of fluid displaced per revolution of an axial piston rotary pump is dependent on the angle formed between the cylinder block and valve plate

    D

    All of the above


    正确答案： B
    解析： 暂无解析

  • 第7题：

    单选题
    The pump discharge pressure will be considerably higher than the pressure at the （）.
    A

    pump entry branch

    B

    outlet pipe

    C

    impeller

    D

    None of the above is true


    正确答案： D
    解析： 暂无解析

  • 第8题：

    单选题
    The amount of fuel delivered by a helical plunger fuel injection pump is controlled by （）
    A

    varying the pump discharge pressure

    B

    varying the pump return pressure

    C

    rotation of the pump plunger

    D

    rotation of the pump barrel


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    The pressure head of a pump is given in the unit of （）.
    A

    kg

    B

    MPa

    C

    meter fluid column

    D

    None of the above is true


    正确答案： C
    解析： 暂无解析

  • 第10题：

    单选题
    The amount of fluid delivered by a helical pump can be regulated by （）.
    A

    throttling the pressure line

    B

    changing the speed of the rotor

    C

    either A or B

    D

    None of the above is tree


    正确答案： B
    解析： 暂无解析

  • 第11题：

    单选题
    Increasing the speed of a rotary pump above its rated speed will result in which of the following conditions to occur?（）
    A

    Loss of suction

    B

    Increased clearances

    C

    Decreased clearance

    D

    Decreased slippage


    正确答案： D
    解析： 暂无解析

  • 第12题：

    单选题
    The （） pump discharges a nearly constant amount of liquid regardless of pressure.
    A

    mixed-flow

    B

    axial-flow

    C

    centrifugal

    D

    displacement


    正确答案： C
    解析： 暂无解析

  • 第13题：

    单选题
    The pressure of a liquid leaving the pump can be referred to as the （）.
    A

    total head

    B

    discharge head

    C

    net positive suction head

    D

    suction head


    正确答案： C
    解析： 暂无解析

  • 第14题：

    单选题
    A positive displacement pump is that where the volume of the pump chamber is alternately increased to （） and then decreased to （）.
    A

    draw the liquid in；force the liquid out

    B

    force the liquid out；draw the liquid in

    C

    suction；draw

    D

    deliver；outlet


    正确答案： C
    解析： 暂无解析

  • 第15题：

    单选题
    Which of the listed pumps is NOT a positive displacement pump?（）
    A

    Centrifugal

    B

    Reciprocating

    C

    Gear

    D

    Rotary


    正确答案： A
    解析： 暂无解析

  • 第16题：

    单选题
    If a hydraulic pump is overheating, the cause may be （）.
    A

    excessive internal leakage in the pump

    B

    low discharge pressure and fluid flow

    C

    excessive fluid level in the hydraulic reservoir

    D

    operation of the pump at 100% efficiency


    正确答案： C
    解析： 暂无解析

  • 第17题：

    单选题
    The amount of fluid delivered by a gear pump can be regulated by （）.
    A

    throttling the pressure line

    B

    changing the speed of the rotor

    C

    either A or B

    D

    None of the above is true


    正确答案： B
    解析： 暂无解析

  • 第18题：

    单选题
    The amount of fluid delivered by a positive displacement pump can be regulated by （）.
    A

    throttling the pressure line

    B

    changing the speed of the driving rotor

    C

    either A or B

    D

    None of the above is tree


    正确答案： B
    解析： 暂无解析

  • 第19题：

    单选题
    Some of the energy fed into the pump will be dissipated as （） due to mechanical inefficiencies, the remainder will be converted into pressure rise and fluid velocity.
    A

    hydraulic head

    B

    static head

    C

    heat energy

    D

    steam


    正确答案： B
    解析： 暂无解析

  • 第20题：

    单选题
    Centrifugal pumps can be designed with a number of impellers （） to attain a high final delivery pressure.
    A

    in series

    B

    in parallel

    C

    either A or B

    D

    None of the above is tree


    正确答案： D
    解析： 暂无解析

  • 第21题：

    单选题
    The pressure head of a water pump is given in the unit of （）.
    A

    kg

    B

    MPa

    C

    mH20

    D

    None of the above


    正确答案： D
    解析： 暂无解析

  • 第22题：

    单选题
    Which of the following statements about pump operations is NOT a correct statement?（）
    A

    In order for a fluid to be pumped, a fluid must be made to flow

    B

    A substance must be cold in order for it to be pumped

    C

    The kinetic energy imparted by the pump can be used to force a liquid through a hydraulic system

    D

    A pump must receive its energy from an external source


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably（）.
    A

    excessive pump speed

    B

    excessive suction head

    C

    worn wearing rings

    D

    gross pump misalignment


    正确答案： D
    解析： 暂无解析

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