_______ is used in several applications in daily life, such as in refrigerator doors, in magnetic compasses and to separate waste materials.

Options

A. Electrostatic force
B. Muscular force
C. Gravitational force
D. Magnetic force

Answer

To solve the question, we need to identify which force is commonly used in the applications mentioned: refrigerator doors, magnetic compasses, and separating waste materials.

### Step-by-Step Solution:

1. **Understanding the Applications**:
- **Refrigerator Doors**: These typically use magnets to ensure the door closes tightly and stays sealed.
- **Magnetic Compasses**: These rely on the Earth's magnetic field to indicate direction.
- **Separating Waste Materials**: Magnetic force is often used in recycling processes to separate ferrous (magnetic) materials from non-ferrous materials.

2. **Identifying the Forces**:
- The options provided are:
- Electrostatic force
- Muscular force
- Gravitational force
- Magnetic force

3. **Analyzing Each Option**:
- **Electrostatic Force**: This is related to electric charges and is not relevant to the applications mentioned.
- **Muscular Force**: This is the force exerted by muscles and is not applicable to the examples given.
- **Gravitational Force**: This force acts between masses and does not pertain to the specific applications listed.
- **Magnetic Force**: This is the force associated with magnets and is directly related to all three applications.

4. **Conclusion**:
- Based on the analysis, the correct answer is **Magnetic Force**. This force is used in refrigerator doors to keep them closed, in magnetic compasses for navigation, and in separating waste materials during recycling.

### Final Answer:
**Magnetic Force** is used in several applications in daily life, such as in refrigerator doors, in magnetic compasses, and to separate waste materials.

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