Question:

A brand new, empty, electrically powered refrigerator with its doors removed is placed in a sealed, perfectly insulated room and is plugged in and turned on remotely. Some time later, what happens to the average temperature of the air in the room?

Options:

• Decreased?
• None of these answers?
• Increased?
• Stayed exactly the same?

Answer: Increased

Detailed Explanation:

When the refrigerator operates, it uses electrical energy to power its cooling cycle. This cycle attempts to remove heat from one area (the interior) and expel it into another (the room).

In an idealized case, a refrigerator transfers heat from inside to outside without adding any energy to the system, but in reality, the process is not 100% efficient.

In this situation, the refrigerator is in a sealed, perfectly insulated room. That means:

• No energy escapes the room.
• All the electrical energy consumed by the refrigerator is converted into thermal energy (heat).

Although the refrigerator attempts to cool the air near its coils, the net result is an overall increase in heat within the room, because:

Total Heat in Room = Heat Extracted from Fridge + Electrical Work Done

Since the room is insulated, none of this energy can escape. Over time, this additional thermal energy raises the temperature of the entire room.

Conclusion:

Therefore, even though a refrigerator cools locally, in an insulated environment it actually raises the overall temperature due to the conversion of electrical energy to heat.

Final Answer:

The average temperature of the air in the room has: Increased