Ferromagnetic substances have

Options

A. Zero magnetic moment
B. Small magnetic moment
C. Large magnetic moment
D. Any value of magnetic moment

Answer

To solve the question regarding ferromagnetic substances, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Magnetic Moments**:
- Magnetic moment is a vector quantity that represents the magnetic strength and orientation of a magnet or other object that produces a magnetic field.

2. **Types of Magnetic Substances**:
- Magnetic substances can be classified into different categories based on their magnetic properties: diamagnetic, paramagnetic, and ferromagnetic.

3. **Characteristics of Ferromagnetic Substances**:
- Ferromagnetic substances are characterized by having a **large magnetic moment**. This is due to the presence of **unpaired electrons** in their atomic structure.

4. **Effect of Unpaired Electrons**:
- In ferromagnetic materials, the unpaired electrons do not cancel each other out. Instead, they align parallel to each other, resulting in a net magnetic moment that is significantly larger.

5. **Conclusion**:
- Based on the above understanding, we can conclude that ferromagnetic substances have a **large magnetic moment**. Therefore, the correct answer to the question is **option C: large magnetic moment**.

6. **Examples of Ferromagnetic Substances**:
- Common examples include iron, cobalt, nickel, gadolinium, and chromium dioxide (CrO2).

### Final Answer:
Ferromagnetic substances have a **large magnetic moment**.

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