MDE 11 Q7

Correct Answer: C) It occurs when the engine is not run at high enough temperatures

Explanation: Condensation forms when the engine does not reach sufficient operating temperature, allowing moisture to condense in the oil and cause 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: 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: 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) It causes the oil to lose its ability to lubricate effectively

  Explanation: Water contamination dilutes the oil and disrupts its lubricating properties, leading to inadequate protection for engine components.

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: B) Periodically cleaning the oil using a centrifugal separator
Explanation: Regular cleaning of the lubricating oil using a centrifugal separator removes contaminants and helps maintain the oil in optimum condition. While changing the oil is important, it’s not as frequent and essential as cleaning.

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.