In following symbols are having usual meaning then which of the following reaction is correct ?

Options

A. `mu_(r) + chi = 1`
B. `-mu_(r) = 1 + chi`
C. `mu_(r) = (mu_(0))/(mu)`
D. `chi = mu_(r) - 1`

Answer

To solve the question regarding the correct relationship between relative permeability (µr) and magnetic susceptibility (χ), we will follow these steps:

### Step 1: Understand the Definitions
- **Relative Permeability (µr)**: This is the ratio of the permeability of a material to the permeability of free space (vacuum).
- **Magnetic Susceptibility (χ)**: This is a dimensionless quantity that indicates how much a material will become magnetized in an applied magnetic field.

### Step 2: Recall the Relationship
The relationship between relative permeability and magnetic susceptibility is given by the following equations:
1. \( \mu_r = \chi + 1 \)
2. \( \chi = \mu_r - 1 \)

### Step 3: Analyze the Options
Given the question, we need to determine which of the provided options correctly represents the relationship between µr and χ.

### Step 4: Identify the Correct Option
From the relationships we recalled:
- If we rearrange the first equation, we see that \( \chi = \mu_r - 1 \) is a valid expression.
- Therefore, if option D states this relationship, it is the correct answer.

### Conclusion
The correct relationship between relative permeability and magnetic susceptibility is:
\[ \chi = \mu_r - 1 \]
Thus, option D is correct.

---