Permeability is defined as the ratio between

Options

A. magnetic induction and susceptibility
B. magnetic indction and magnetising field
C. magnetising field and magnetic induction
D. magnetising field and magnetic induction

Answer

To solve the question about the definition of permeability, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Permeability**:
Permeability (μ) is a measure of how easily a magnetic field can penetrate a material. It is defined in terms of the relationship between magnetic induction (B) and the magnetizing field (H).

2. **Write the Formula for Permeability**:
The formula for permeability is given by:
\[ \mu = \frac{B}{H} \]
where:
- \( B \) is the magnetic induction (also known as magnetic flux density),
- \( H \) is the magnetizing field (also known as magnetic field strength).

3. **Identify the Ratio**:
From the formula, we can see that permeability is the ratio of magnetic induction to the magnetizing field. This means:
\[ \text{Permeability} = \frac{\text{Magnetic Induction}}{\text{Magnetizing Field}} \]

4. **Evaluate the Options**:
Now, let's evaluate the given options based on our understanding:
- **Option A**: Magnetic induction and susceptibility - Incorrect.
- **Option B**: Magnetic induction and magnetizing field - Correct.
- **Option C**: Magnetic field and magnetic induction - Incorrect.
- **Option D**: Magnetic field and magnetic induction - Incorrect.

5. **Conclusion**:
The correct answer is **Option B**: Magnetic induction and magnetizing field.