State the purpose of using the following in an electric circuit.
Rheostat

Explanation

### Step-by-Step Solution:

1. **Definition of Rheostat**:
- A rheostat is a type of variable resistor that is used to control the flow of electric current in a circuit. It consists of a coil or wire wound around a cylindrical tube, which allows for the adjustment of resistance.

2. **Purpose of Rheostat**:
- **Adjusting Resistance**: The primary purpose of a rheostat is to adjust the resistance in an electric circuit. By changing the position of the slider or contact point along the coil, the resistance can be increased or decreased, which directly affects the current flowing through the circuit.

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