On which principle is refrigorator based?

Explanation

To answer the question "On which principle is a refrigerator based?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Function of a Refrigerator**:
- A refrigerator's main function is to cool a designated space by removing heat from it.

**Hint**: Consider what happens to the temperature of an area when heat is removed.
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