MDE 11 End of Unit Quiz

• Correct Answer: B) A rotating bowl or rotor

Explanation: The rotating bowl or rotor is the key component that creates the centrifugal force needed to separate contaminants from the oil. As the rotor spins at high speed, the centrifugal force causes the heavier contaminants to move outward and accumulate on the inner wall of the bowl, while the cleaner oil remains closer to the center and is then recirculated.

Correct Answer: B) To assess the oil’s ability to neutralize acids
Explanation: The TBN measures the oil's ability to neutralize acidic byproducts from combustion, which is critical to preventing corrosion and maintaining engine health.

Correct Answer: C) By using a series of filter media that cause small water droplets to merge into larger droplets, which are then easily separated.

Explanation:
Coalescer filters use specialized filter media designed to coalesce, or combine, small water droplets in the fuel into larger droplets. Once the water droplets are large enough, they can be separated from the fuel more easily, typically settling out and being removed via a water separator.

Correct Answer: C) Regularly cleaning and maintaining the separator

Explanation: Regular maintenance ensures that the separator operates efficiently, reducing the risk of incomplete separation and oil losses.

• Correct Answer: A) It is returned directly to the engine's lubrication system

Explanation: After the oil has been cleaned in the centrifugal filter, it is returned directly to the engine's lubrication system to continue its role in lubricating, cooling, and cleaning the engine components. The design of the system ensures that the oil is continuously filtered and reused, maintaining the engine's performance and longevity.

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:
D) The filter causes small droplets of water or other liquids to merge into larger droplets, which are then separated from the oil.

Explanation: A coalescer lubricating oil filter works by using materials that cause small droplets of water or other liquids to coalesce, or merge, into larger droplets. These larger droplets are easier to separate from the oil, allowing them to be removed efficiently, thus purifying the oil from water or other liquid contaminants.

• Correct Answer: C) Oil is spun at high speed to separate contaminants based on density

Explanation: The centrifugal filter operates by spinning the oil at high speed within the rotor. This high-speed rotation creates a centrifugal force that causes the denser particles (contaminants) to move outward, separating them from the less dense, cleaner oil. This process is entirely mechanical and relies on the principle of density differences.

Correct Answer: C) A damaged water pump

Explanation: A damaged water pump can lead to coolant leakage, which may then mix with the engine oil and cause water contamination.

Correct Answer: B) A higher flow rate results in higher discharge frequency

Explanation: A higher flow rate means more oil is processed through the purifier in a given time, which can increase the rate at which contaminants build up and thus require more frequent discharges.

Correct Answer: B) It can cause the oil to become foamy

Explanation: Water contamination in the oil can cause it to become emulsified and foamy, reducing its lubricating properties.

Correct Answer: C) Incomplete separation of contaminants

Explanation: Incomplete separation can lead to oil carryover, where the oil mixed with contaminants exits the separator, causing oil losses.