PART A $(25$ pts$)$: You are asked to assess the efficiency of a refrigerator based on several common practices. Consider the following scenarios:

A refrigerator is kept full to reduce the amount of cold air lost when the door is opened.

A hot pan is placed directly into the refrigerator after being taken from the oven.

The condenser coils of the refrigerator are cleaned periodically to improve cooling performance.

Items are stored on top of the refrigerator, potentially obstructing airflow.

The refrigerator is set to a temperature much lower than the manufacturer's recommended setting.

a$)(20$ pts $)$: For each of the scenarios listed above, explain whether it is likely to increase or decrease the refrigerator's energy consumption and why. In your answer, consider thermodynamic principles related to heafransfer, energy balance, and work input.

b$)(5$ pts $)$: Which practices align with the goals of maximizing refrigerator efficiency, and how do they relate to the basic thermodynamics of the system?