Why does a wire get heated when it is bent back and forth ?

Explanation

### Step-by-Step Solution:

1. **Understanding the Concept of Work Done**:
- When a wire is bent back and forth, an external force is applied to change its shape. This action requires energy, which is referred to as work done on the wire.

2. **Energy Transformation**:
- The work done on the wire is not stored as potential energy in the wire. Instead, it is transformed into thermal energy (heat) due to the internal friction and resistance within the material of the wire.

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