輪機英語期末考試試題A卷

1、輪機英語A卷姓名： 成績： 單項選擇題（每題2分共100分）1. The diesel engine is similar to the gasoline engine in that _.A. Both of them are ignited by compressed airB. Both of them are the forms of external combustion enginesC. Both of them have spark plugsD. The power is developed by the piston in the cylinder2. The ratio

2、of th brake horsepower to the indicated by the _.A. Thermal efficiency B. Mechanical efficiency C. Brake thermal efficiency D. Volumetric efficiency3. The ignition quality, of diesel fuel oil is indicated by the _.A. Specific gravity B. Cetane number C. Viscosity D. Calorific value4. How are the pre

3、ssure and temperature affected in a diesel engine cylinder during compression?A. Pressure and temperature decreaseB. Pressure and temperature increase C. Pressure decreases and temperature increasesD. Pressure increases and temperature decreases5. An aluminium piston has lower inertia and higher coe

4、fficient of _compared to that of cast ironA. Viscosity B. Twisting moments C. Inertia D. Thermal expansion6. Each cylinder is closed at the top by a _,made of a special heat-resistant steel.A. Cylinder liner B. Coupling flange C. Cylinder cover D. Piston7. The amount of fuel delivered by a helical p

5、lunger type fuel injection pump is controlled by_.A. Rotation of the pump plunger B. Rotation of the pump barrel C. Varying the pump supply pressure D. Varying the pump return pressure8. In a diesel engine lube oil system, which of the following parts should be lubricated first?A. Camshaft bearing B

6、. Main bearing C. Piston crowns D. Cylinder9. Sacrificial zinc anodes are used on he saltwater side of diesel engine heat exchangers to_.A. Reduce electrolytic action on heat exchanger metalsB. Keep heat transfer surfaces shiny and cleanC. Prevent rapid accumulation of marine growthD. Provide a prot

7、ective coating on heat exchanger surfaces10. In a turbocharger, inlet air velocity is in creased in the _.A. Inlet nozzle ring B. Stationary diffuser passages C. Compressor outlet volute D. Rotating impeller vanes11. Diesel engine cylinder air start valve timing is controlled by _.A. Engine operatin

8、g speed B. An air manifold C. A hydraulic distributor D. The air distributor12. If the compensating needle valve of a hydraulic governor is opened more than necessary the governor will_.A. Have a larger than normal dead bandB. Produce excessive speed response to a load changeC. Respond slowly to any

9、 change in engine loadD. Stabilize engine speed at the new governor setting13. A pyrometer is an instrument commonly used to measure_.A. Cylinder pressure B. Flame intensity C. Exhaust gas temperature D. Crankshaft axial alignment14. pump up the starting air reservoirs to their maximum pressure and

10、_the air reservoirs and airA. Open B. close C. Drain D. Vent15. In reducing engine speed to an efficient propeller speed by the use of reduction gears,_.A. Speed and torque are both reduced B. Speed is reduced and torque remains unchangedC. Speed is reduced and torque is increasedD. Speed is sometim

11、es unchanged while torque is increased16. Which of the following statements concerning fire-tube boilers is correct?A. Combustion gases flow through the tubes B. Flames impinge(撞擊) on the tube C. Combustion occurs in the tubes D. Water flows through the tubes17. The safety valves should be tested an

12、d adjusted when the boiler survey is _.A. Completed B. Carried out C. Cleaned D. Steamed18. When an auxiliary boiler is panting and emitting black smoke, you should _.A. Increase the fuel oil supply pressure B. Decrease the fuel oil C. Decrease the fuel oil supply pressure D. Increase the air supply

13、 19. If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be _.A. High steam pressure in the boiler B. Abnormally high feed-water temperature C. Abnormally high boiler water temperature D. Steam demand exceeding feed pump capacity20. A vane pump belon

14、gs to_according to its working principle.A. Reciprocating pump B. Positive displacement pump C. Centrifugal pump D. centripetal pump21. The packing installed in the pump stuffing box is lubricated by_.A. Gravity and feed oil cups B. Grease cups C. Hand during installation D. Leakage through the stuf

15、fing box22. If the capacity of a centrifugal pump decreases gradually over a long period of time, you should_.A. Packing gland B. Mechanical seals C. Lantern rings D. Wearing rings23. Which of the listed conditions can lead to cavitation in a centrifugal pump?A. Vapor pockets formed in the suction f

16、low steamB. Rough casing volute surfaces.C. Worn wearing rings D. Heavy fluid m the flow stream24. In a compression refrigeration plant, the hot, high pressure refrigerant gas is cooled by the sea water and becomes liquid in the _.A. Compressor B. Condenser C. Throttle valve D. Evaproator25. The tem

17、perature at winch water vapor in the atmosphere begins to condense is called the _.A. Dew point temperature B. Condensation temperature C. Psychometric temperature D. Absolute humidity temperature26. In an air conditioning system, moisture is removed from the air by_.A. Filters B. Separator C. Ducte

18、d traps D. Dehumidifiers27. Sludge may form in the crankcase of an air conditioning compressor as a result of _.A. Bubbling refrigerant B. Lowered operating temperaturesC. Overheating and oxidation D. Reducing the cloud or floe point28. Coalescence is the breakdown of surface tension between oil dro

19、plets in an oil/ water mixture. Which causes them to join and _in size.A. Expand B. Extract C. Increase D. Decrease29. when started, a complete oily water separating unit is first filled_.the oily water mixture is _ then pumped through the inlet pipe into the coarse separating compartment. A. With d

20、irty water B. With clean water C. By oily water D. By mixed water30. Which is the pollution prevention equipment?A. Booster pump B. Evaporator C. Incinerator D. Cooler31. The _is used to bum oil sludgeA. Clarifier B. Oily water separator C. Incinerator D. Distiller32. In sewage treatment, the termma

21、cerationrefers to the process of _.A. Breaking up solid matter into fine particlesB. Precipitating non-decomposed waste in a collection tankC. Chemically adjusting the sewage pH to 7.0D. Eliminating bacterium coil from the sewage33. Which of the substances listed is satisfactorily removed from the f

22、uel by a centrifugal oil purifier?A. Carbon particles B. Lube oil C. Gasoline D. Diesel fuel34. If the bowl of a disk type centrifugal purifier when operated as a separator is not primed, the _.A. Oil has a tendency to emulsify in the bowl B. purifier will act as a clarifier at the discharge ringC.

23、Oil will be lost through the water discharge portsD. Oil solids will be deposited only at the intermediate top disk35. The process of boiling seawater in order to separate it into freshwater vapor and brine is usually defined as _.A. Dehydration B. Condensation C. Evaporation D. Dissolution36. What

24、type of valve is used to direct the flow of hydraulic is controlled by varying the position of the _A. Relief valve B. Direction control valve C. Stop valve D. Pressure control valve37. The delivery rate of a variable stroke axial piston hydraulic pump is controlled by varying the position of the _.

25、A. Slide block B. Tilting box C. Pintle D. Reaction ring38. The drive motor will have a brake arranged to fail-safe,i.e.it wild the load if power fail or _machine is stopped.A. Lift B. Put C. Take D. Hold39. On tank vessels with an electrically-driven capstan, the motor should be meggered periodical

26、ly to test_.A. Insulation resistance B. Eddy currents B. C. Capacitance D. Armature reactance40. Overheating of a hydraulic system may be a result of _.A. Changing pump discharge pressure in response to normal load variationsB. A high oil levelC. Incorrect fluid viscosityD. Continued slow re-circula

27、tion of the oil41. Purging air from a hydraulic system is necessary when _.A. Adding small amounts of oil to the systemB. The system has been overheatedC. The system has been drained and then filled with new oilD. The system has been idle for a long period of time42. A direct current passing through

28、 a wire coiled around a soft iron core is the description of a simple_.A. Magnetic shield B. Electromagnet C. Piezoelectric device D. Electromagnetic domain43. The operation of _two alternators requires the voltages to be equal and also in phase.A. Paralleling B. Series-mounting C. Running D. Contro

29、lling44. The power factor of an AC generator operating singularly is determined by the _.A. Connected load B. Prime mover speed B. C. Field excitation D. Generators rated voltage45. A generator is prevented from becoming motorized by the used of a/an _.A. Over-speed trip B. Reverse power relay B. C.

30、 Back pressure trip D. Governor controls46. After a ship enters service it is _for the main bus-bar to be made dead.A. Usually B. Commonly C. Exceptional D. Unavoidably47. A transformer in an electric circuit serves to_.A. Generate its own electrical powerB. Transform electrical energy into mechanical en