Magnetic susceptibility is positive for

Options

A. Non-magnetic materials
B. Paramagnetic materials
C. Ferromagnetic materials
D. Diamagnetic materials

Explanation

To determine for which materials the magnetic susceptibility is positive, we need to understand the concept of magnetic susceptibility and its values for different types of materials.

### Step-by-Step Solution:

1. **Understanding Magnetic Susceptibility**:
- Magnetic susceptibility (χ) is a measure of how much a material will become magnetized in an applied magnetic field. It is defined as the ratio of magnetization (M) to the magnetic field intensity (H).
- The formula is given by:
\[ \chi = \frac{M}{H} \]
- Magnetic susceptibility is a dimensionless quantity.

2. **Types of Magnetic Materials**:
- **Diamagnetic Materials**:
- These materials have a negative magnetic susceptibility (χ < 0). They are weakly repelled by a magnetic field.
- **Paramagnetic Materials**:
- These materials have a positive magnetic susceptibility (χ > 0). They are weakly attracted by a magnetic field.
- **Ferromagnetic and Superparamagnetic Materials**:
- These materials also have a positive magnetic susceptibility, and their values can be significantly greater than zero (χ >> 0). They exhibit strong attraction to magnetic fields.

3. **Conclusion**:
- From the analysis, we can conclude that magnetic susceptibility is positive for:
- **Paramagnetic materials** (χ > 0)
- **Ferromagnetic materials** (χ >> 0)
- **Superparamagnetic materials** (χ >> 0)
- Therefore, the correct options for materials with positive magnetic susceptibility are paramagnetic, ferromagnetic, and superparamagnetic materials.

### Final Answer:
Magnetic susceptibility is positive for **paramagnetic materials**, **ferromagnetic materials**, and **superparamagnetic materials**.