MDE 1 End of Unit Quiz

MDE 1 End Of Unit Quiz

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10. Supercharging

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

D) Improved fuel quality

A) Reduced engine weight

C) Lower exhaust emissions

B) Increased engine efficiency and power output

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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?

C) Remains stationary

A) Downward away from the cylinder head

B) Upward toward the cylinder head

D) Moves sideways within the cylinder

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7. Role of the Compression Stroke in Power Output

Question: How does the compression stroke affect the power output of a marine diesel engine?

D) It has no effect on power output

C) It prepares the air for combustion, indirectly contributing to power output

B) It reduces power output by increasing engine resistance

A) It directly increases the power output by compressing the fuel

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2. Valve Operation During Compression Stroke

Question: During the compression stroke of a four-stroke marine diesel engine, which valves are closed?

C) Exhaust valve only

A) Both intake and exhaust valves

D) Both intake and exhaust valves are open

B) Intake valve only

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4. Effect on Air Temperature During Compression Stroke

Question: What happens to the temperature of the air inside the cylinder during the compression stroke in a marine diesel engine?

D) It fluctuates

A) It decreases

C) It increases

B) It remains the same

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5. Timing of Fuel Injection

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

A) During the intake stroke

C) At the end of the compression stroke

B) At the beginning of the compression stroke

D) During the exhaust stroke

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4. Effect on Air Temperature During Compression Stroke

Question: What happens to the temperature of the air inside the cylinder during the compression stroke in a marine diesel engine?

B) It remains the same

A) It decreases

D) It fluctuates

C) It increases

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5. Pressure Changes During Exhaust Stroke

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

D) It fluctuates randomly

A) It increases significantly

B) It remains constant

C) It decreases as the piston moves upward

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6. Compression Ratio in Diesel Engines

Question: Why is the compression ratio typically higher in diesel engines compared to gasoline engines?

A) To increase engine speed

D) To reduce engine noise

C) To ensure the air is hot enough to ignite the fuel

B) To improve fuel atomization

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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

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

C) It increases slightly

B) It remains constant

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Transfer of Gas Force from Piston Crown to Crankshaft

Question: How is the force generated by the combustion gases transferred from the piston crown to the crankshaft in a four-stroke diesel engine?

A) Through the connecting rod which converts the linear motion of the piston into rotational motion

C) Via the camshaft which then drives the crankshaft

D) Through the exhaust valves which push the crankshaft

B) Directly through the piston rings which transfer force to the crankshaft

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