When the door of a refrigerator is kept open then the room temperature starts

Options

A. cool down
B. hot up
C. first cool down then hot up
D. neither cool down nor hot up

Explanation

To solve the question, we need to analyze the functioning of a refrigerator and how it affects the surrounding environment when its door is left open.

### Step-by-Step Solution:

1. **Understanding the Function of a Refrigerator:**
- A refrigerator works on the principle of heat transfer. It removes heat from the inside (the refrigerated space) and expels it to the outside environment (the room).
- The refrigerator uses work (usually electrical energy) to transfer heat from a cooler area (inside the fridge) to a warmer area (the room).

2. **Considering the Scenario of an Open Door:**
- When the refrigerator door is left open, the entire room becomes the source of heat for the refrigerator.
- The refrigerator will attempt to cool the room by absorbing heat from it.

3. **Heat Transfer Process:**
- The refrigerator absorbs heat \( Q \) from the room and expels it back into the room, along with additional heat generated due to the work \( W \) done by the refrigerator.
- The total heat expelled into the room is \( Q + W \).

4. **Conclusion on Room Temperature:**
- Since the refrigerator is expelling more heat into the room than it is removing (because of the work done), the overall effect is that the room temperature will increase.
- Therefore, when the door of the refrigerator is kept open, the room will get hotter.

5. **Final Answer:**
- The correct option is that the room temperature starts to "hot up."