Suscepitbility is positive and large for a

Answer

To determine which material has a positive and large susceptibility, we can analyze the relationship between susceptibility and temperature, particularly focusing on different types of magnetic materials: ferromagnetic, paramagnetic, and diamagnetic materials.

### Step-by-Step Solution:

1. **Understanding Susceptibility**:
- Susceptibility (χ) is a measure of how much a material will become magnetized in an applied magnetic field. It can be positive or negative, indicating whether the material is attracted to or repelled by the magnetic field.

2. **Types of Magnetic Materials**:
- **Ferromagnetic Materials**: These materials have a large positive susceptibility. They can retain magnetization even after the external magnetic field is removed. Examples include iron, cobalt, and nickel.
- **Paramagnetic Materials**: These materials have a small positive susceptibility. They are weakly attracted to magnetic fields and do not retain magnetization once the field is removed.
- **Diamagnetic Materials**: These materials have a negative susceptibility. They are repelled by magnetic fields and do not retain magnetization.

3. **Graph of Susceptibility vs. Temperature**:
- To visualize the behavior of susceptibility, we can draw a graph with susceptibility (χ) on the y-axis and temperature (T) on the x-axis.
- The graph will show different regions:
- **AB Region**: This region corresponds to ferromagnetism, where susceptibility is positive and large.
- **BC Region**: This region corresponds to paramagnetism, where susceptibility is positive but small.
- **Point for Diamagnetism**: This point indicates negative susceptibility.

4. **Identifying the Correct Material**:
- From the graph, we can see that in the AB region (ferromagnetism), susceptibility can vary from 1000 to 10,000, indicating that it is both positive and large.
- Therefore, we conclude that the material with positive and large susceptibility is a **ferromagnetic material**.

### Final Answer:
The susceptibility is positive and large for **ferromagnetic materials**.