Aux 1 Unit 11 Q6

Correct Answer: B) Excellent conformability to the shaft, allowing it to accommodate slight misalignments and reduce wear

Explanation: White metal is known for its excellent conformability, meaning it can accommodate slight misalignments between the shaft and bearing, which helps reduce wear and prolongs the bearing's life.

Correct Answer: B) Sensitivity to contamination, where foreign particles can embed in the soft material, causing damage to both the bearing and shaft

Explanation: One disadvantage of white metal is its sensitivity to contamination. The soft material can allow foreign particles to embed, leading to damage to the bearing and the shaft over time.

Correct Answer: B) It enhances the bearing's ability to dissipate heat, reducing the risk of overheating under load.

Explanation: White metal has good thermal conductivity, which enhances its ability to dissipate heat. This property is important in reducing the risk of overheating, especially in high-load applications.

Correct Answer: B) They may need regular inspection and replacement due to wear, especially if contaminated or subjected to improper lubrication.

Explanation: White metal bearings may require regular inspection and replacement due to their susceptibility to wear, particularly if they become contaminated or are not properly lubricated. This can increase maintenance costs and effort.

Correct Answer: B) Excellent corrosion resistance, making it ideal for use in harsh marine environments

Explanation: Plastic materials offer excellent corrosion resistance, which makes them ideal for use in harsh marine environments where exposure to seawater can be a significant concern for other materials.

Correct Answer: B) It reduces the need for additional lubrication, simplifying maintenance and reducing operational costs.

Explanation: Certain plastic materials are self-lubricating, which reduces the need for additional lubrication. This property simplifies maintenance and can reduce operational costs associated with regular lubrication.

Correct Answer: B) Lower load-bearing capacity compared to metals, which can lead to deformation or failure under high loads

Explanation: Plastic materials generally have a lower load-bearing capacity compared to metals like white metal. This can be a disadvantage under high-load conditions, where the plastic may deform or fail.

Correct Answer: B) It can cause changes in bearing clearance as the temperature fluctuates, potentially leading to misalignment or increased wear.

Explanation: Plastic materials tend to have higher thermal expansion rates than metals. This can lead to changes in bearing clearance as temperatures fluctuate, potentially causing misalignment or increased wear if not properly managed.

Correct Answer: B) The initial cost may be higher for certain high-performance plastics, although they can offer longer service life in some applications.

Explanation: High-performance plastics used in stern bearings can have a higher initial cost compared to more traditional materials. However, this can be offset by their longer service life and lower maintenance requirements in specific applications.

Correct Answer: B) It has good load-bearing capacity and can absorb shock loads effectively, reducing the risk of bearing failure under heavy loads.

Explanation: White metal is used in high-load applications because it has a good load-bearing capacity and can effectively absorb shock loads. This makes it a reliable choice for stern bearings where heavy loads are common.