The permeability of a material is 0.9990 The material must be

Options

A. 1. diamagnetic
B. 2.paramagnetic
C. 3.ferromagnetic
D. 4. a conductor

Answer

To determine the type of material based on its permeability, we can follow these steps:

### Step 1: Understand the concept of permeability
Permeability (μ) is a measure of how easily a material can support the formation of a magnetic field within itself. It is often expressed in terms of relative permeability (μ_r), which is the ratio of the permeability of the material to the permeability of free space (μ₀).

### Step 2: Analyze the given value of permeability
The problem states that the permeability of the material is 0.9990. This value is less than 1.

### Step 3: Identify the implications of relative permeability values
- If μ_r < 1, the material is classified as **diamagnetic**. Diamagnetic materials create an opposing magnetic field when exposed to an external magnetic field, leading to a repulsive effect.
- If μ_r = 1, the material is considered **non-magnetic** (like air).
- If μ_r > 1, the material can be classified as **paramagnetic** (weakly attracted to magnetic fields) or **ferromagnetic** (strongly attracted to magnetic fields).

### Step 4: Conclude the type of material
Since the given relative permeability (0.9990) is less than 1, we conclude that the material must be **diamagnetic**.

### Final Answer:
The material must be **diamagnetic**.

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