网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
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
参考答案
参考解析
解析：
暂无解析
更多 “单选题The amount of fluid delivered by a helical pump can be regulated by （）.A throttling the pressure lineB changing the speed of the rotorC either A or BD None of the above is tree” 相关考题
考题
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
考题
Before doing any work on a hydraulic system equipped with accumulators, you shouldA.drain the accumulators and purge with oxygenB.bleed off all stored energy from the accumulators completelyC.charge the accumulators to prevent system energy lossD.pump the hydraulic fluid into the accumulators to prevent fluid loss
考题
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
考题
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
考题
What causes cavitation in a centrifugal pump ________．A.Vapor pockets in the flow streamB.Rough impeller surfacesC.Worn wearing ringsD.Heavy fluid in the flow stream
考题
An SSL VPN can be used in conjunction with IBM Tivoli Access Manager for Enterprise Single Sign-On to provide remote access to business critical information. Which statement is true about the Mobile ActiveCode （MAC） when it is used with a VPN Solution for remote access？（）A、The MAC can only be delivered to a mobile phone and is good for a single use only.B、The MAC can be delivered by mobile phone， e-mail， or fax， and it is good for one time authentication only.C、The MAC can only be delivered to a mobile phone and it is good until the expiration time is reached， as set by an administrator.D、The MAC can be delivered by mobile phone， email， or fax， and it is good until the expiration time is reached， as set by an administrator.
考题
单选题The amount of fluid delivered by a helical pump can be regulated by （）.A
throttling the pressure lineB
changing the speed of the rotorC
either A or BD
None of the above is tree
考题
单选题Pressure in an operating hydraulic system is developed （）.A
only by the pump as its primary functionB
by resistance to the fluid flow through the systemC
by the thermal input to the systems fluidD
solely by the charge applied by the accumulators
考题
单选题Which of the processes listed consumes the greatest amount of power while producing the greatest amount of heat?（）A
Overcoming sliding frictionB
Overcoming rolling frictionC
Overcoming fluid frictionD
Overcoming oil wedge friction
考题
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 flowB
A substance must be cold in order for it to be pumpedC
The kinetic energy imparted by the pump can be used to force a liquid through a hydraulic systemD
A pump must receive its energy from an external source
考题
单选题If a hydraulic pump is overheating, the cause may be （）.A
excessive internal leakage in the pumpB
low discharge pressure and fluid flowC
excessive fluid level in the hydraulic reservoirD
operation of the pump at 100% efficiency
考题
单选题An advantage of a helical gear pump over a simple gear pump is that the helical gear pump is capable of （）.A
maintaining a steadier speedB
delivering liquids over greater distancesC
operating for longer periods of timeD
producing a smoother discharge flow
考题
单选题The amount of fuel delivered by a unit injector is controlled by the （）A
camshaftB
main springC
rack positionD
nozzle orifice size
考题
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 cylinderB
the pump camC
the pump plungerD
the pump miler
考题
单选题A pump is defined as device that（）A
produces pressureB
imparts energy to a fluid to move it from level ‘A’ to level ‘B’C
creates a vacuum to move a liquid in all installationD
is to develop a pressure differential
考题
单选题If a radial piston hydraulic pump fails to deliver rated fluid volume, the cause can be （）.A
contaminated fluidB
pitted thrust ringsC
worn pintle bearingsD
obstructed suctions passage
考题
单选题When the tilting box of a variable stroke axial-piston pump is perpendicular to the pump shaft, which of the following conditions will exist?（）A
The pistons reciprocateB
The ‘B’ end cylinder barrel rotatesC
There is no fluid flowD
Power is transmitted hydraulically
考题
单选题The amount of fluid delivered by a gear pump can be regulated by （）.A
throttling the pressure lineB
changing the speed of the rotorC
either A or BD
None of the above is true
考题
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 speedB
A radial piston pump houses sliding pistons in a stationary cylinder block through which passes a rotating pintle or ported shaftC
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 plateD
All of the above
考题
单选题In a radial piston pump, reversal and control of fluid flow are accomplished by moving the （）.A
central valveB
radial plungerC
floating ringD
cylinder body
考题
单选题In a shell-and-tube type hydraulic fluid cooler, the amount of heat transferred from the hydraulic fluid to the cooling water depends upon（）A
the temperature of the hydraulic fluidB
the flow rate of the hydraulic fluidC
the temperature of the cooling waterD
all of the above
考题
单选题The pipe friction and the resistance will （） as a result of an increase in the amount of fluid flowing through the system.A
reduceB
riseC
raiseD
fall
考题
单选题The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.A
specific gravityB
viscosityC
S E numberD
hydrolytic stability
考题
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 headB
static headC
heat energyD
steam
考题
单选题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
考题
单选题Which of the listed conditions can lead to cavitation气穴in a centrifugal pump?（）A
Vapor pockets formed in the suction flow streamB
Rough easing volute surfacesC
Worn wearing ringsD
Heavy fluid in the flow stream
考题
单选题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
考题
单选题The pressure head of a pump is given in the unit of （）.A
kgB
MPaC
meter fluid columnD
None of the above is true
热门标签
最新试卷
