【正文】 ept of reciprocity互惠 Jimei University *1065 A secondary function of diesel engine piston rings is to_____. A. reduce friction losses in the engine B. absorb the piston side thrust C. prevent cylinder liner wear D. prevent excess lubricant from reaching the bustion space 1066 Barrel face, taper face, grooved, and chrome plated are all types of diesel engine_____. A. pistons B. piston rings C. piston skirts D. cylinder liners Jimei University 1067 Diesel engines are classified as reciprocating internal bustion engines because they _____. A. use energy from fuel burned outside their cylinders B. burn fuel in a bustion chamber that moves back and forth C. burn fuel in a chamber where its energy moves a piston back and forth D. use a continuous bustion process to impart rotary motion to the pistons Jimei University *1068 A main propulsion diesel engine is normally shut down by_____. A. shutting off the air supply B. overspeeding the engine C. securing the fuel supply D. securing the ignition system 通常是通過切斷燃油供應來停車的 。輪機工程學院輔機教研室 輪機英語考試強化復習 （ 3000KW及以上船舶二管輪 /三管輪 ） Jimei University 1001 Exhaust valve grooving and corrosion is caused by certain ponents of residual fuel oil. These ponents are sodium, sulfur, and_____. A. vanadium B, carbon C. copper D. ash Jimei University 1002 Whether using a centrifuge or a simple filter, oil cleaning and filtration will be the most effective when the oil is at a_____. A. high temperature and a high viscosity B. high temperature and a low viscosity C. low temperature and a high viscosity D. low temperature and a low viscosity Jimei University *1003 High firing pressures and a low exhaust temperature in a diesel engine may result from_____. A. decreased piston to cylinder head clearance B. increased exhaust system back pressure C. early fuel injection timing D. low scavenge air temperature Jimei University 1004 Poor bustion in a diesel engine can be caused by _____. A. high pression pressure B. low intake air temperature C. low exhaust pressure D. high scavenge air pressure Jimei University *1005 The longer the ignition delay period occurs in a diesel engine, the_____. A. less fuel will enter the cylinder B. lower will be cylinder pression temperatures C. more plete will be fuel bustion D. more rapid will be the rise in bustion pressure Jimei University *1006 The load is always placed on the lower half of the main bearings in a/an_____. A. twostroke/cycle engine B. fourstroke/cycle engine C. reverse cycle engine D. double acting engine *1007 Which term describes piston pins having bearing surfaces in both the piston bosses and connecting rod eye? A. Stationary B. Full floating C. Semifloating D. Free rolling Jimei University 1008 Diesel engine fuel oil leakage should be drained and additional precautions provided to _____. A. return this oil to the proper storage tank B. prevent contamination of lubricating oil by fuel oil C. ascertain an accurate measurement of this leakage D. drain cooling water system ponents Jimei University 1009 Which of the following devices is mon to both mechanical and hydraulic governors? A. Direct linkage between the ballhead and fuel rack. B. A servomotor. C. A pensating device. D. Flyweights. Jimei University *1010 Which of the following conditions will tend to increase the ignition delay period of bustion in a pression ignition engine? A. Using a fuel oil with a higher cetane number. B. Decreasing the air charge temperature. C. Reducing the injected fuel oil droplet size. D. Increasing the pression ratio. Jimei University 1011 When is fuel injected into a cylinder of diesel engines? A. Before air in the cylinder is pressed. B. After air in the cylinder is pressed. C. After bustion gases in the cylinder have expanded. D. As air is taken into the cylinder. Jimei University 1012 Injection lag can be caused by_____. A. improper timing of the intake valves B. setting of the pump plunger C. pressibility of the fuel D. position of the needle valve Jimei University 1013 If the raw water supply pressure for a diesel engine cooling system is below normal, you should check for a_____. A. broken thermostat B. clogged sea strainer C. blown head gasket D. cracked head Jimei University 1014 A change in the degree of fuel atomization in a diesel engine cylinder has the greatest effect on the_____. A. cylinder air turbulence B. fuel spray angle C. fuel injection rate D. bustion in that cylinder Jimei University 1015 The rate of pressure rise during the period following fuel ignition process in a diesel engine is influenced chiefly by the_____. A. percent of CO2 B. range of inflammability C. theoretical fuel/air ratio D. length of the ignition delay period Jimei University 1016 On most diesel engines, the governor controls the output speed by_____. A. controlling the amount of fuel injected into the cylinders B. varying the speed of the turbocharger C. adjusting the pression ratio D. changing the timing of the fuel injection camshaft Jimei University 1017 Why is it necessary to press the air charge in the cylinders of a diesel eng