What is the basic use of hysteresis curve?

Options

A. Paramagnetic materials
B. Diamagnetic materials
C. Ferromagnetic materials
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding Hysteresis Curve**:
- The hysteresis curve is a graphical representation of the relationship between the magnetic field strength (H) and the magnetic flux density (B) in a material. It shows how the magnetization of a material lags behind the applied magnetic field.

2. **Application in Ferromagnetic Materials**:
- The hysteresis loop is particularly important for ferromagnetic materials. These materials exhibit a significant amount of magnetization even after the external magnetic field is removed, which is known as remanence.

3. **Induced Magnetism**:
- In ferromagnetic materials, the induced magnetism is strong enough to create a distinct hysteresis loop. This loop provides valuable information about the material's magnetic properties, such as coercivity (the resistance to demagnetization) and saturation magnetization (the maximum magnetization achievable).

4. **Use in Material Selection**:
- The hysteresis curve is used to select materials for various applications. For example, materials with low hysteresis loss are preferred in electrical transformers and magnetic cores to minimize energy loss.

5. **Conclusion**:
- The basic use of the hysteresis curve is to study the magnetic properties of ferromagnetic materials, which helps in understanding their behavior under varying magnetic fields and aids in material selection for specific applications.