单选题Worn main bearing will cause the compression ratio of an auxiliary diesel engine to（）A increaseB decreaseC remain the sameD increase on compression decrease on expansion

题目
单选题
Worn main bearing will cause the compression ratio of an auxiliary diesel engine to（）
A

increase

B

decrease

C

remain the same

D

increase on compression decrease on expansion

相似考题

1.If a firm has a quick ratio of 1, the subsequent payment of an account payable will cause the ratio to increase.()此题为判断题(对，错)。

2.Low compression in a diesel engine could be caused byA.worn or broken cylinder liner sealing ringsB.high cooling water temperatureC.worn or broken piston ringsD.low fuel oil pressure

3.If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably _____.A.misalignment or worn main bearingsB.insufficient cylinder lubricationC.defective or poorly fitted valvesD.All of the above

4.Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?A.compression must be low for effective spark ignitionB.compression must be low for required horsepower and torque generationC.compression must be low to prevent pre-ignitionD.compression must be low to have effective pre-ignition

更多“Worn main bearing will cause the compression ratio of an aux”相关问题

  • 第1题：

    音频出入的MAIN口和AUX口说法正确的是()

    A.MAIN口和AUX口都没有回声抵消功能

    B.Main接口有回声抵消功能，听不到自己的声音

    C.Aux接口没有回声抵消功能，可以听见自己的声音

    D.两个接口都有回声体抵消功能


    参考答案：B, C

  • 第2题：

    材料：

    Spark erosion is caused by a voltage discharge between the main bearing and journal surface. The cause of the potential is the development of a galvanic element between the ship’s hull, sea water, and the propeller shaft/crankshaft.

    The oil film acts as a dielectric. The puncture voltage in the bearing depends on the thickness of the oil film. With increasing engine ratings, the specific load in the main bearing is increased. his will reduce the oil film thickness, and enable the discharge to take place at a lower voltage level.

    Since the hydrodynamic oil film thickness varies through a rotation cycle, the discharge will take place at roughly the same instant during each rotation cycle, i.e. when the film thickness is at its minimum. The roughening will accordingly be concentrated in certain areas on the journal surface. In the early stages, the roughened areas can resemble pitting erosion. but later, as the roughness increases, the small craters will scrape off and pick up white metal-hence the silvery white appearance.

    Therefore, to ensure protection against spark erosion, the potential level must be kept at maximum 80 mV, which is feasible today with a high efficiency earthing device. If an earthing device is installed, its effectiveness must be checked regularly. Spark erosion is only observed in main bearings and main bearing journals.

    问题：

    According to the paragraph one, a voltage between the main bearing and journal surface is produced by______.

    A.propeller rotation

    B.leakage from M/E electric control unit

    C.a galvanic element

    D.friction between the main bearing and journal surface

    ______engine ratings increase, the hydrodynamic oil film between the main bearing and journal surface is______.A.The lower/thinner

    B.The higher/the thicker

    C.The lower/thicker

    D.The higher/thinner

    When will the spark erosion take place on the journal surface during each rotation cycle?A.when the film thickness is at its minimum

    B.when the film thickness is at its maximum

    C.when the engine is on its compression stroke

    D.when the engine is on its exhaust stroke

    During the engine room watch keeping, which equipment must be noted to ensure protection against spark erosion?A.the antifouling plant

    B.the earthing device

    C.the main engine electric heating coils

    D.the shaft generator

    请帮忙给出每个问题的正确答案和分析，谢谢！


    问题 1 答案解析：C


    问题 2 答案解析：D


    问题 3 答案解析：A


    问题 4 答案解析：B

  • 第3题：

    Which of these terms refers to call issues that cause variations in timing or time of arrival？（）

    • A、queuing
    • B、jitter
    • C、packet loss
    • D、digitized sampling
    • E、signal-to-noise ratio ratio

    正确答案:B

  • 第4题：

    单选题
    Worn main bearings in a diesel engine can result in （）
    A

    decreased compression pressure

    B

    increased lube oil pressure

    C

    lower lube oil temperature

    D

    excessive leakage past the piston rings


    正确答案： D
    解析： 暂无解析

  • 第5题：

    单选题
    Which of the listed bearing types is an example of a solid bearing?（）
    A

    Piston wrist pin bushing

    B

    turbine bearing

    C

    Spring bearing

    D

    Diesel engine main bearing


    正确答案： A
    解析： 暂无解析

  • 第6题：

    单选题
    Low compression of diesel engine may result from （）
    A

    a worn cylinder

    B

    broken piston rings

    C

    any of A and B

    D

    none of the above


    正确答案： A
    解析： 暂无解析

  • 第7题：

    单选题
    A distance piece, with ground faces, may be interposed between the rod and the bearing housing, its thickness being chosen to ensure the correct （）.
    A

    expansion ratio

    B

    pressure ratio

    C

    compression ratio

    D

    clearance ratio


    正确答案： D
    解析： 暂无解析

  • 第8题：

    单选题
    Measure （） by means of lead wire.
    A

    the clearance of the main bearing

    B

    the play of the miler bearing

    C

    the gap of the main bearing

    D

    the tolerance of the main bearing


    正确答案： D
    解析： 暂无解析

  • 第9题：

    单选题
    If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably （）.
    A

    misalignment or worn main bearings

    B

    insufficient cylinder lubrication

    C

    defective or poorly fitted valves

    D

    all of the above


    正确答案： A
    解析： 暂无解析

  • 第10题：

    单选题
    To determine the main bearing clearance of a propulsion diesel engine, you should measure the main bearing shell using a ball anvil outside micrometer and measure the crankshaft journal using a/an （）
    A

    telescoping

    B

    ring ‘snap’ gauge

    C

    inside vernier caliper

    D

    outside micrometer


    正确答案： A
    解析： 暂无解析

  • 第11题：

    单选题
    If a diesel engines exhaust temperature is abnormally high, the cause could be（）
    A

    too light of a load

    B

    injection timing is too early

    C

    overloading of the engine

    D

    too low of a compression ratio


    正确答案： C
    解析： 暂无解析

  • 第12题：

    单选题
    A possible cause for an individual piston to knock when at TDC on a slow-speed, two-stroke/cycle main propulsion diesel engine could be due to （）
    A

    early fuel injection

    B

    excessive bearing play within the running gear

    C

    overloading of the cylinder

    D

    all of the above


    正确答案： A
    解析： 暂无解析

  • 第13题：

    Adjust ______by means of lead wire.

    A.the clearance of the main bearing

    B.the diameter of main bearing

    C.the gap of main bearing

    D.the tolerance of main bearing


    正确答案：A

  • 第14题：

    A wobbling tail shaft is an indication of ______.

    A.shallow water

    B.an engine that is misfiring

    C.a tight tail shaft gland

    D.worn stern bearing or misalignment


    正确答案：D
    一个摇晃的为轴显示了轴封以损坏。

  • 第15题：

    音频出入的MAIN口和AUX口说法正确的是（）

    • A、MAIN口和AUX口都没有回声抵消功能
    • B、Main接口有回声抵消功能，听不到自己的声音
    • C、Aux接口没有回声抵消功能，可以听见自己的声音
    • D、两个接口都有回声体抵消功能

    正确答案:B,C

  • 第16题：

    单选题
    Adjust （） by means of lead wire.
    A

    the clearance of the main bearing

    B

    the diameter of main bearing

    C

    the gap of main beating

    D

    the tolerance of main bearing


    正确答案： B
    解析： 暂无解析

  • 第17题：

    单选题
    Which of the following operating conditions can occur when shims are removed from the joint between the foot of a marine type diesel engine connecting rod and the bearing box?（）
    A

    Decreased connecting rod bearing clearance

    B

    Increased connecting rod bearing clearance

    C

    Decreased compression ratio

    D

    Increased compression ratio


    正确答案： C
    解析： 暂无解析

  • 第18题：

    单选题
    If the compression ratio is increased on any diesel engine, （）
    A

    the expansion ratio will decrease

    B

    combustion will be slowed down

    C

    thermal efficiency will decrease

    D

    thermal efficiency will increase


    正确答案： B
    解析： 暂无解析

  • 第19题：

    单选题
    For a given fuel, a change in the compression ratio will affect the ignition lag by which of the listed means?（）
    A

    An increase in compression ratio will increase the ignition lag

    B

    An increase in compression ratio will decrease the ignition lag

    C

    A decrease in compression ratio will decrease the ignition lag

    D

    A decrease in ignition lag will increase the compression ratio


    正确答案： C
    解析： 暂无解析

  • 第20题：

    单选题
    Low compression results from （）.
    A

    a worn cylinder

    B

    broken piston rings

    C

    either A or B

    D

    none of the above


    正确答案： C
    解析： 暂无解析

  • 第21题：

    单选题
    The insertion of shims between the foot of a marine type connecting rod and a bearing box would result in （）
    A

    increased compression ratio

    B

    decreased compression ratio

    C

    increased bearing clearance

    D

    decreased bearing clearance


    正确答案： B
    解析： 暂无解析

  • 第22题：

    单选题
    Which of the following relationships should occur between the temperature developed in a combustion space, and the compression ratio of the engine?（）
    A

    Higher compression ratios create higher temperature

    B

    Higher temperatures create higher compression ratios

    C

    low temperatures create higher compression ratios

    D

    Higher compression ratios create low temperatures


    正确答案： A
    解析： 暂无解析

  • 第23题：

    单选题
    Higher than normal temperature air passing through the intake of a diesel engine will result in（）
    A

    greater overall efficiency

    B

    greater fuel economy

    C

    lower horsepower

    D

    lower compression ratio


    正确答案： C
    解析： 暂无解析

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