單項選擇題Which of the following statements concerning the lubrication of diesel propulsion engines used in vessels over 300 gross tons is most accurate?（）

A.Lubrication systems using engine driven lube oil pumps do not require any additional independent arrangement when such arrangements have been proven reliable
B.The use of engine driven pre-lube pumps is permitted on vessels with propulsion systems developing less than 500 shaft horsepower
C.When forced lubrication is used for propulsion engines, one independently driven stand-by pumps is to be provided in addition to the necessary pumps for normal operation
D.Lubrication systems where two oil coolers are fitted require a minimum of two temperature control devices which may be actuated by similar sensors


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1.單項選擇題If the coolant temperature of a closed cooling water system for a diesel engine gradually increases, the trouble usually is （）

A.a broken shaft on the freshwater pump
B.an excessive accumulation of scale exchanger
C.an incorrect thermostatic element operating range
D.lube oil in the cooling water

2.單項選擇題The amount of fuel delivered by a helical plunger fuel injection pump is controlled by （）

A.varying the pump discharge pressure
B.varying the pump return pressure
C.rotation of the pump plunger
D.rotation of the pump barrel

3.單項選擇題On a diesel engine equipped with a hydraulic speed control governor, hunting in many cases can be corrected by adjusting the （）

A.accumulator spring compressor
B.balance piston
C.compensating needle valve
D.proportional piston

4.單項選擇題Which of the following adjustments is always required whenever the diesel engine governor oil has been drained and renewed?（）

A.speed droop
B.compensation
C.idle speed setting
D.load limit control

5.單項選擇題Which of the following statements represents an advantage of an electromagnetic clutch?（）

A.Large misalignments can be tolerated between the shaft and engine coupling
B.Slip is held to a minimum when reversing shaft rotation
C.Engine torsion vibrations to the driven shaft are eliminated
D.It aids in maintaining power factor