轮机英语试题 液压系统和设备

Lesson 20

1817. A hydraulic motor may be driven by_____.

A. an electric motor

B. a diesel engine

C. a compressor

D. oil

1818. In a hydraulic system, _____ are used to protect the system from over pressure.

A. stop valves

B. check valves

C. safety valves

D. reducing valves 1819. Among the basic categories of equipment, which of the following are used to allow the hydraulic energy to be controlled?

A. hydraulic pumps

B. valves

C. hydraulic cylinders

D. hydraulic motors

1820. Among the basic categories of equipment, which of the following are used to Convert mechanical into hydraulic energy?

A. The hydraulic pumps

B. Valves

C. Hydraulic cylinders

D. Hydraulic motors

1821. Among the basic categories of equipment, which of the following is used to Convert hydraulic energy into continuous rotary motion?

A. Hydraulic pumps

B. Valves

C. Hydraulic cylinders

D. Hydraulic motors 1822. The rotor of the hydraulic motor rotates at a speed proportional to the_____.

A. flow of oil

B. pressure of oil

C. A and B

D. temperature of oil 1823. What type of valve is used to direct the flow of hydraulic fluid?

A. Relief valve

B. Direction control valve

C. Stop valve

D. Pressure control valve

1824. External and internal leakage in hydraulic systems may be caused by_____. A. unusual vibration B. excessive worn parts

C. abnormal pressure

D. any of the above

1825. Among the basic categories of equipment, which of the following are used to convert the hydraulic energy into linear motion?

A. Hydraulic pumps

B. Valves

C. Hydraulic cylinders

D. Hydraulic motors

1826. _____ play a very important part in hydraulic systems by preventing interaction between different parts of the hydraulic circuit.

A. Motors

B. Check valves

C. Safety valves

D. Reducing valve 1827. Which of the following can be used in hydraulic transmission system?

A. Hydraulic oil

B. Animal oil

C. Light oil

D. Fuel oil

1828. A hydraulic machine is one that uses _____ to do work.

A. liquid

B. steam

C. gas

D. electricity

1829. Hydraulic machinery failures are commonly caused by misalignment of the

system components and by_____.

A. hydraulic fluid contamination

B. excessive fluid friction

C. turbulent fluid flow

D. fluid pressure surges

1830. Hydraulic machinery failures are commonly caused by contamination of the hydraulic fluid and_____.

A. fluid friction

B. fluid turbulence

C. component misalignment

D. pressure surges

1831. Overheating of a hydraulic system may be a result of_____.

A. changing pump discharge pressure in response to normal load variations

B. a high oil level

C. incorrect fluid viscosity

D. continued slow re-circulation of the oil

1832. 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.

1833. When normal operating pressure is applied to the hydraulic oil used in a high-pressure system, the oil_____.

A. viscosity will decrease

B. volume will increase

C. volume will decrease

D. pour point will be reduced

1834. Which characteristic or condition will have the greatest effect on increasing a hydraulic oil's viscosity?

A. Pour point

B. Cloud point

C. Vacuum

D. Pressure

1835. Sluggish response or action of the hydraulic actuators may be a result of_____.

A. insufficient load

B. excessively high oil viscosity

C. relief-valve pressure setting too high

D. reservoir level being maintained two inches above normal

1836. Flexible hose under pressure in a hydraulic system will_____.

A. tend to twist about its long axis

B. expand in length and in diameter

C. contract in length and expand in diameter

D. flex at right angles to the applied pressure

1837. Pressure in an operating hydraulic system is developed_____.

A. only by the pump as its primary function

B. by resistance to the fluid flow through the system

C. by the thermal input to the system's fluid

D. solely by the charge applied by the accumulators