Question

When a certain paramagnetic material is placed in an external magnetic field of 1.50T , the field inside the material is measured to be 1.5023T .

Part A

The relative permeability of this material is

The relative permeability of this material is

	1.0015.
	0.0015.
	1.
	10.015

Part B

The magnetic permeability of this material is

The magnetic permeability of this material is

	0T.m/A.
	1.259.10?7T.m/A.
	1.259.10?6T.m/A.
	1.259.10?5T.m/A.

Answer 1

Part A:

The relative permeability of a material is defined as the ratio of magnetic field in the material divided by the magnetic field in air.

$$ \begin{aligned} \mu_{r} &=\frac{B}{B_{0}} \\ &=\frac{1.5023}{1.50} \\ &=1.0015 \end{aligned} $$

Part B:

The relative permeability in terms of the permeability of the material and permeability of the air is,

$$ \begin{aligned} \mu_{r} &=\frac{\mu}{\mu_{0}} \\ \mu &=\mu_{r} \mu_{0} \\ &=(1.0015)\left(4 \pi \times 10^{-7} \mathrm{~T} \cdot \mathrm{m} / \mathrm{A}\right) \\ &=1.25856 \times 10^{-6} \mathrm{~T}=1.259 \times 10^{-6} \mathrm{~T} \end{aligned} $$