If the alignment of magnetic moments in a subtance is in a compensatory way so as to give zero net magnetic moment, then the substance is said to be

Options

A. ferromagnetism
B. anit-ferromagnetism
C. ferrimagnetism
D. dimagnetism

Answer

To solve the question, we need to understand the concept of magnetic moments in substances and how they align.

### Step-by-Step Solution:

1. **Understanding Magnetic Moments**:
- Magnetic moments are vectors that represent the magnetic strength and orientation of a magnet or magnetic material. They arise from the motion of electric charges, particularly electrons.

2. **Alignment of Magnetic Moments**:
- In certain materials, the magnetic moments of atoms or ions can align in various ways. The alignment can be parallel (ferromagnetism), antiparallel (antiferromagnetism), or random (paramagnetism).

3. **Compensatory Alignment**:
- The question specifies that the alignment of magnetic moments is "compensatory," meaning that the moments are arranged in such a way that they cancel each other out. This results in no net magnetic moment.

4. **Definition of Antiferromagnetism**:
- When the magnetic moments of adjacent atoms or ions align in opposite directions (antiparallel), they cancel each other out, leading to a net magnetic moment of zero. This phenomenon is known as antiferromagnetism.

5. **Conclusion**:
- Therefore, if the alignment of magnetic moments in a substance is compensatory, resulting in a zero net magnetic moment, the substance is classified as an **antiferromagnetic substance**.

### Final Answer:
The substance is said to be **antiferromagnetic**.

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