A hydraulic machine is one that uses () to do work.
A . liquid
B . steam
C . gas
D . electricity
相似题目
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If the compensating needle valve of a hydraulic governor is opened more than necessary the governor will ()
A . have a larger than normal dead band
B . produce excessive speed response to a load change
C . respond slowly to any change in engine load
D . stabilize engine speed at the new governor setting
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One function provided by a hydraulic accumulator is to()
A . provide an area where air can separate from the oil
B . provide an area to separate solid contaminants from the oil
C . act as an oil and water separator
D . absorb shocks occurring in the system
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In a fixed displacement axial piston hydraulic motor, the speed is varied by()
A、regulating the ratio between torque and speed via the torque limiter at the motor
B、directing the motor output flow through a bypass line
C、maintaining a constant flow and pressure input
D、controlling the input flow rate
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To parallel an incoming machine to a running machine therefore it is necessary to ensure firstly that ().
A . two frequencies must be brought into phase
B . the incoming machine accepts a small amount of load
C . the running machine must be unload
D . both voltages are equal
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An orifice-check valve placed in a hydraulic system is used to()
A . regulate the fluid flow in either direction
B . restrict movement of hydraulic fluid in one direction, but allow free movement in the other direction
C . allow free movement of hydraulic fluid in both directions
D . allow a restricted fluid flow in one direction only
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() is a machine by which electrical energy is transformed into mechanical energy.
A . An alternator
B . An electric motor
C . A diesel engine
D . A main switchboard
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The purpose of the compensating adjustment used in a diesel engine hydraulic governor is to ()
A . compensate for low oil level
B . increase governor promptness
C . prevent governor hunting
D . limit engine load
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Each machine in the internet is assigned a unique network address,called(),that is used to identify the machine for communication purposes
A . A、MAC address
B . B、IP address
C . C、host address
D . D、domain name address
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The major cause of trouble in a mechanical-hydraulic governor is contamination of the hydraulic fluid by ()
A . dirt
B . fuel oil
C . governor cooling water
D . fuel oil tar
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As for a hydraulic single action vane pump, the inner wall of the stator is usually of () shape.
A . circular
B . elliptical
C . rectangular
D . hexago
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A hydraulic accumulator is designed to().
A . store fluid under pressure
B . act as a fluid reservoir
C . provide overpressure relief
D . replenish fluid to a system
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A large change in ambient temperature, or using an oil of a viscosity different from the one recommended by the manufacturer in a mechanical hydraulic governor, will result in the need to adjust the ().
A . pilot valve opening
B . compensating needle valve
C . compensating spring tension
D . accumulator spring tensio
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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
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When the desired rudder angle is attained by a typical double mm electro-hydraulic steering gear,the().
A . ram relief valves bypass oil to stop rudder movement
B . six-way valve shifts to the neutral flow position
C . steering pump electric motor is de - energized by the transfer switch
D . follow-up gear takes the hydraulic pump off stroke
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If the pump for a hydraulic anchor windlass is overheating, the cause may be ().
A . excessive drive motor speed
B . excessive pump discharge pressure
C . too low of a tilting box angle
D . insufficient drive motor speed
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When the first-shift supervisor arrives at his office each day, one of his importantmissions is to exam the machines carefully.
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DNC is a self-contained NC system for a single machine tool.
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Which is a potential hazard when operate a machine tool?
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Layer n on one machine carries on a conversation with layer n on another machinE.The rules and conventions used in this conversation are collectively known as the layer n
A. topology
B.protocol
C.service
D.peer
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Before the cherry-picking machine was invented, a present orchard worker's one day's work is equal to amount of work done by ______.
A.three hundred and fifty farmers a day
B.one hundred farmers two weeks
C.two hundred farmers two weeks
D.thousands of farmers a day
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One of our clients in Singapore is _________ the market _________ Chinese sewing machines.
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When the relief valve is used as a constant pressure valve, it is connected to the outlet of the hydraulic pump to ensure that the outlet pressure of the hydraulic system (pump) is constant.
A:正确;
B:错误
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A cash-generating unit comprises the following assets: $’000Building 700Plant and equipment 200Goodwill 90Current assets 20 1,010One of the machines, carried at $40,000, is damaged and will have to be
A.$597,000
B.$577,000
C.$594,000
D.$548,000
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Washer is a machine ____ (用它我们洗衣服)or a person who is washing.