Define magnetic susceptibility of a material. Name two elements, one having positive susceptibility and the other having negative susceptibility . What does negative susceptibility signify ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Magnetic Susceptibility:**
Magnetic susceptibility (χ) of a material is defined as the ratio of the magnetization (M) of the material to the applied magnetizing field intensity (H). Mathematically, it can be expressed as:
\[ \chi = \frac{M}{H} \]
where:
...