MDE 1 End of Unit Quiz

MDE 1 End Of Unit Quiz

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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

A) To expel exhaust gases from the cylinder

B) To ignite the air-fuel mixture

D) To draw fresh air into the cylinder

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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?

D) To ignite the air-fuel mixture

C) To expel combustion gases from the cylinder

A) To draw fresh air into the cylinder

B) To compress the air-fuel mixture

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6. Pressure in the Cylinder During Intake

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

B) It decreases slightly

A) It increases significantly

D) It becomes higher than the atmospheric pressure

C) It remains constant

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2. Valve Operation During Exhaust Stroke

Question: During the exhaust stroke of a four-stroke marine diesel engine, which valve is open?

A) Intake valve

D) Neither valve

C) Both intake and exhaust valves

B) Exhaust valve

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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

B) Increased engine efficiency and power output

C) Lower exhaust emissions

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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?

B) Intake valve only

C) Exhaust valve only

D) Both intake and exhaust valves are open

A) Both intake and exhaust valves

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7. Significance of the Intake Stroke

Question: Why is the intake stroke crucial for the operation of a four-stroke marine diesel engine?

C) It controls the engine speed

B) It ensures the cylinder is filled with a fresh charge of air for combustion

A) It initiates the ignition process

D) It determines the engine’s fuel efficiency

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7. Potential Issues During Exhaust Stroke

Question: What could happen if the exhaust valve fails to open properly during the exhaust stroke of a marine diesel engine?

D) The fuel will not ignite during the power stroke

C) The combustion gases will remain in the cylinder, causing poor performance

B) The engine will produce more power

A) The cylinder will overfill with fresh air

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6. Timing of the Power Stroke

Question: When does the power stroke occur in the four-stroke cycle of a marine diesel engine?

A) Immediately after the intake stroke

C) Immediately after the compression stroke

D) Immediately after the power stroke

B) Immediately after the exhaust stroke

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9. Scavenge Systems

Question: What is the purpose of the scavenging system in a two-stroke marine diesel engine?

A) To increase fuel injection pressure

D) To lubricate the piston rings

B) To remove exhaust gases and fill the cylinder with fresh air

C) To cool the cylinder head

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8. Exhaust System in Diesel Engines

Question: What is the role of the exhaust system connected to the cylinder during the exhaust stroke?

C) It channels the exhaust gases out of the engine

B) It filters the air entering the cylinder

D) It injects fuel into the cylinder

A) It cools down the intake air

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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?

D) Moves sideways within the cylinder

A) Downward away from the cylinder head

C) Remains stationary

B) Upward toward the cylinder head

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