MDE 1 End of Unit Quiz

MDE 1 End Of Unit Quiz

1 / 12

2. Valve Operation During Compression Stroke

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

A) Both intake and exhaust valves

B) Intake valve only

C) Exhaust valve only

D) Both intake and exhaust valves are open

2 / 12

7. Role of the Compression Stroke in Power Output

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

B) It reduces power output by increasing engine resistance

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

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

D) It has no effect on power output

3 / 12

2. Valve Operation During Exhaust Stroke

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

C) Both intake and exhaust valves

B) Exhaust valve

A) Intake valve

D) Neither valve

4 / 12

8. Fuel Systems

Question: Which of the following is a common cause of fuel injection pump failure in marine diesel engines?

A) High exhaust back pressure

B) Contaminated fuel

C) Insufficient air intake

D) Excessive lubricating oil

5 / 12

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?

C) It increases

A) It decreases

D) It fluctuates

B) It remains the same

6 / 12

Penetration in Fuel Combustion

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

B) The distance fuel droplets travel into the combustion chamber before igniting

C) The process of breaking down fuel into smaller droplets for better combustion

A) The ability of the fuel to mix with air before combustion

D) The amount of fuel that evaporates before reaching the combustion chamber

7 / 12

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?

C) It remains constant

B) It decreases slightly

D) It becomes higher than the atmospheric pressure

A) It increases significantly

8 / 12

Components in a Cross-Section of a Four-Stroke Diesel Engine Piston

Question: In a cross-section view of a four-stroke diesel engine piston, which of the following components are typically visible?

B) Camshaft, crankshaft, and connecting rod

A) Piston crown, piston rings, and piston skirt

C) Fuel injector, turbocharger, and intake valve

D) Exhaust valve, rocker arm, and valve spring

9 / 12

5. Timing of Fuel Injection

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

B) At the beginning of the compression stroke

A) During the intake stroke

C) At the end of the compression stroke

D) During the exhaust stroke

10 / 12

10. Supercharging

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

C) Lower exhaust emissions

A) Reduced engine weight

D) Improved fuel quality

B) Increased engine efficiency and power output

11 / 12

1. Purpose of the Power Stroke

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

B) To draw fresh air into the cylinder

C) To convert the energy from combustion into mechanical work

A) To compress the air-fuel mixture

D) To expel exhaust gases from the cylinder

12 / 12

2. Valve Operation During Intake Stroke

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

D) Neither intake nor exhaust valve

C) Both intake and exhaust valves

A) Exhaust valve

B) Intake valve

Your score is