Lubricants are used between the two parts of a machine. Why ?

Answer

**Step-by-Step Solution:**

1. **Understanding Friction**: Friction is the force that opposes the relative motion of two surfaces in contact. When two parts of a machine move against each other, friction is generated.

2. **Surface Roughness**: Even surfaces that appear smooth to the naked eye have microscopic irregularities. When these surfaces come into contact, the irregularities interlock, leading to increased friction.

3. **Role of Lubricants**: Lubricants are substances that are applied between the moving parts of a machine. They fill the microscopic gaps and create a thin film that separates the surfaces.

4. **Reduction of Friction**: By introducing a lubricant, the interlocking of surface irregularities is minimized. This significantly reduces the friction between the moving parts.

5. **Benefits of Reduced Friction**:
- **Improved Efficiency**: With less friction, machines can operate more smoothly and efficiently, requiring less energy to perform the same work.
- **Reduced Wear and Tear**: Lower friction means that the surfaces experience less wear, extending the lifespan of the machine parts.
- **Prevention of Overheating**: Reduced friction also leads to less heat generation, which can prevent overheating and potential damage to the machine.

6. **Conclusion**: Therefore, lubricants are essential in machines to reduce friction, enhance performance, and prolong the life of the machine components.

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