MDE 1 End of Unit Quiz

MDE 1 End Of Unit Quiz

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2. Piston Movement During Power Stroke

Question: In which direction does the piston move during the power stroke of a four-stroke marine diesel engine?

C) Remains stationary

A) Upward toward the cylinder head

B) Downward away from the cylinder head

D) Moves sideways within the cylinder

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10. Supercharging

Question: Which of the following is a benefit of supercharging in a marine diesel engine?

A) Reduced engine weight

B) Increased engine efficiency and power output

D) Improved fuel quality

C) Lower exhaust emissions

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3. Lubrication Systems

Question: Which of the following is the primary function of a lubricating oil system in a marine diesel engine?

D) To control the engine speed

A) To increase combustion efficiency

C) To reduce friction between moving parts

B) To remove heat from the engine

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4. Air-Fuel Mixture in Intake Stroke

Question: What is drawn into the cylinder during the intake stroke in a marine diesel engine?

A) A mixture of air and fuel

D) Exhaust gases

C) Pure air

B) Pure fuel

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8. Temperature Changes During Power Stroke

Question: What happens to the temperature inside the cylinder during the power stroke of a four-stroke marine diesel engine?

A) It decreases significantly

B) It remains constant

D) It starts high and decreases as the piston moves downward

C) It increases slightly

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7. Role of the Power Stroke in Engine Operation

Question: Why is the power stroke considered the most critical stroke in the operation of a four-stroke marine diesel engine?

C) It generates the force needed to produce mechanical work

D) It compresses the air-fuel mixture for combustion

A) It removes exhaust gases from the cylinder

B) It introduces fresh air into the cylinder

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3. Piston Movement in Compression Stroke

Question: In which direction does the piston move during the compression stroke of a four-stroke marine diesel engine?

B) Upward toward the cylinder head

D) Moves sideways within the cylinder

C) Remains stationary

A) Downward away from the cylinder head

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Compression Ratio in Fuel Combustion

Question: What does the term "compression ratio" refer to in the context of fuel combustion in a marine diesel engine?

D) The ratio of the amount of fuel injected to the amount of air compressed

A) The ratio of the volume of fuel to the volume of air in the combustion chamber

B) The ratio of the engine's power output to the fuel consumption rate

C) The ratio of the maximum to the minimum volume of the combustion chamber during the engine cycle

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1. Purpose of the Compression Stroke

Question: What is the primary purpose of the compression stroke in a four-stroke marine diesel engine?

C) To compress the air in the cylinder

D) To draw fresh air into the cylinder

B) To ignite the air-fuel mixture

A) To expel exhaust gases from the cylinder

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5. Timing of Fuel Injection

Question: When is fuel typically injected into the cylinder of a marine diesel engine?

C) At the end of the compression stroke

B) At the beginning of the compression stroke

A) During the intake stroke

D) During the exhaust stroke

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Factors Influencing Penetration

Question: Which of the following factors primarily influence the penetration of fuel in the combustion chamber of a marine diesel engine?

D) Compression ratio and turbocharger boost

A) Fuel temperature and injector nozzle design

C) Fuel density and exhaust pressure

B) Engine speed and intake air temperature

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1. Purpose of the Exhaust Stroke

Question: What is the primary purpose of the exhaust stroke in a four-stroke marine diesel engine?

C) To expel combustion gases from the cylinder

B) To compress the air-fuel mixture

D) To ignite the air-fuel mixture

A) To draw fresh air into the cylinder

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