Susceplibility of a magnetic substance is found to depend on temperature and the strength of the magnetising field. The material is a

Options

A. Diamagnet
B. Ferromagnet
C. Paramagnet
D. Superconductor

Answer

To determine the type of magnetic material based on the dependence of susceptibility on temperature and the strength of the magnetizing field, we can analyze the characteristics of different magnetic materials.

### Step-by-Step Solution:

1. **Understand Magnetic Susceptibility**:
- Magnetic susceptibility (χ) is a measure of how much a material will become magnetized in an applied magnetic field. It indicates the ease with which a material can be magnetized.

2. **Identify Types of Magnetic Materials**:
- **Diamagnetic Materials**: These materials have a negative susceptibility and do not depend on temperature or the strength of the magnetic field. They are weakly repelled by a magnetic field.
- **Paramagnetic Materials**: These materials have a positive susceptibility that is less than one. Their magnetization is weak and also depends on temperature, but not as strongly as ferromagnetic materials.
- **Ferromagnetic Materials**: These materials have a very high positive susceptibility (much greater than one). Their magnetization is significantly affected by both temperature and the strength of the magnetizing field. They can retain magnetization even after the external field is removed.
- **Superparamagnetic Materials**: These materials exhibit a susceptibility that can be very high but is also influenced by temperature and the magnetic field.

3. **Analyze the Given Information**:
- The question states that the susceptibility of the magnetic substance depends on both temperature and the strength of the magnetizing field. This characteristic is typical of ferromagnetic materials.

4. **Conclusion**:
- Based on the analysis, the material in question is a **ferromagnetic material**. This is because ferromagnetic substances are known to have their susceptibility depend on both temperature and the strength of the applied magnetic field.

### Final Answer:
The material is a **ferromagnetic substance**.