Explain why a Carnot engine cannot have 100% efficiency?

Explanation

To explain why a Carnot engine cannot have 100% efficiency, we can follow these steps:

### Step 1: Understand the Efficiency Formula
The efficiency (η) of a Carnot engine is given by the formula:
\[ \eta = 1 - \frac{T_2}{T_1} \]
where:
- \( T_1 \) is the absolute temperature of the heat source (hot reservoir).
- \( T_2 \) is the absolute temperature of the heat sink (cold reservoir).
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