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輪機(jī)英語(yǔ)船舶輔助機(jī)械章節(jié)練習(xí)(2018.01.07)

單項(xiàng)選擇題
Which of the following statements describes the functions of a reservoir used in a hydraulic system?（）
A.Dissipate heat
B.Trap foreign matter
C.Separate air from the oil
D.All of the above
單項(xiàng)選擇題
Under normal conditions, the refrigerant enters the compressor in an operating refrigeration system as a （）.
A.liquid
B.dry saturated gas
C.wet saturated gas
D.superheated vapor
單項(xiàng)選擇題
If a centrifugal pump were continually operated with the discharge valve closed, the （）.
A.motor controller overload would open
B.pump would eventually overheat
C.relief valve would continuously cycle open
D.motor would overheat
單項(xiàng)選擇題
An AC synchronous transmission type remote steering control system consists of a （）.
A.transmitter at the steering station and a receiver at the steering engine
B.reversible motor at the steering station geared to the steering pumps
C.small induction motor on the bridge which controls the redder through pulleys
D.variable displacement hydraulic pump driven by a reversible DC motor
單項(xiàng)選擇題
A cracked diaphragm in a thermostatic expansion valve will cause the valve to （）.
A.return to a neutral position
B.flood the evaporator
C.open
D.close
單項(xiàng)選擇題
For many years marine centrifuges were designed for （） operation, that is the machines were run for a period during which solids accumulated in the bowlThe machine was stopped when the accumulated solids began to impair its performance.
A.purifying
B.batch
C.long period
D.temporary
單項(xiàng)選擇題
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
單項(xiàng)選擇題
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
單項(xiàng)選擇題
The latent heat of evaporation is dissipated in the （） in a compression refrigeration system.
A.evaporator
B.condenser
C.expansion valve
D.compressor
單項(xiàng)選擇題
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
A.refrigerant overcharge
B.overfeeding by the expansion valve
C.a restricted suction strainer
D.due to short cycling of the compressor