MDE 11 End of Unit Quiz

Correct Answer: A) A larger capacity purifier will have a lower discharge frequency

Explanation: A purifier with a larger capacity can handle more oil before needing to discharge contaminants, thus reducing the frequency of discharges.

• Correct Answer: C) To remove contaminants from the oil by using centrifugal force

Explanation: The primary function of a centrifugal type lubricating oil filter is to remove contaminants such as dirt, metal particles, and other impurities from the lubricating oil. It does this by spinning the oil at high speeds in a rotating bowl or rotor, which generates centrifugal force. This force pushes the denser contaminants to the outer wall of the rotor, separating them from the cleaner oil.

Correct Answer: B) By regularly testing the oil's viscosity, water content, and acid number
Explanation: Regular testing of the oil's physical and chemical properties is essential to monitor its condition and determine if it remains effective.

Correct Answer: C) Formation of oil sludge

Explanation: Water in engine oil can cause the formation of sludge, which can impede the flow of oil and affect lubrication.

Correct Answer: C) A leaking cylinder head gasket

Explanation: A leaking cylinder head gasket can allow coolant or water to mix with the engine oil, leading to contamination.

Correct Answer: B) By conducting a crackle test
Explanation: The crackle test involves heating a small amount of oil to check for the presence of water, indicated by crackling or popping sounds as the water evaporates.

Correct Answer: B) They are collected in a water separator and drained off.

Explanation:
After the water droplets coalesce into larger droplets, they are separated from the fuel. These larger water droplets are typically collected in a water separator, where they can be drained off to prevent them from entering the engine fuel system, which could cause damage or operational issues.

Correct Answer:
C) The filter uses centrifugal force to separate contaminants from the oil.

Explanation: A centrifugal lubricating oil filter operates by spinning the oil at high speeds, which generates centrifugal force. This force pushes heavier contaminants, such as dirt, metal particles, and sludge, to the outer edges of the filter, effectively separating them from the cleaner oil. The clean oil can then be recirculated back into the engine, while the contaminants remain trapped in the filter.

Correct Answer: A) By preventing oil leakage through seal and joint failures

Explanation: Proper sealing and joint integrity prevent oil from leaking out of the separator, thus minimizing oil losses.

• Correct Answer: B) They are collected on the inner wall of the rotating bowl

Explanation: The contaminants are separated from the oil by the centrifugal force generated by the rotating bowl. As the oil spins, the denser contaminants are forced outward and collect on the inner wall of the bowl, where they remain until the filter is cleaned or serviced. The cleaner oil is then returned to the engine.

Correct Answer: B) To separate water from fuel by causing small water droplets to combine into larger droplets.

Explanation:
The primary function of a coalescer type filter is to separate water from fuel. It works by causing small water droplets dispersed in the fuel to coalesce (combine) into larger droplets, which can then be easily separated from the fuel. This is essential in preventing water contamination in the fuel, which can cause corrosion and other operational issues in a diesel engine.

Correct Answer: B) Regularly monitoring and adjusting the separator’s speed

Explanation: Properly adjusting the separator’s speed according to the oil’s characteristics can help optimize separation efficiency and reduce oil carryover.