Question

The relative magnetic permeability of a magnetic material is 800. Identify the nature of magnetic material and state its own properties.

Answer 1

Hint: The relative magnetic permeability of a magnetic material differs for different materials which depend on the mutual interactions in the external magnetic field. Materials are categorized as diamagnetic, paramagnetic and ferromagnetic substances if their relative magnetic permeability is ${\mu }_r<1,{\mu }_r>1$ and ${\mu }_r>>1$ respectively.

Complete step by step answer: Magnetic permeability of a substance or material is the degree up to which the magnetic lines of forces can enter that substance. It is also the characteristic of a medium that allows the magnetic flux to pass through it. It is denoted by $$\mu$$.
Relative permeability of the medium is derived from magnetic permeability as the ratio of permeability of any medium to that of air or free space. It is denoted by $$\mu$$.
${\mu }_r={\displaystyle \frac{\mu }{{\mu }_0}}$
Here, $${\mu }_0=$$ absolute permeability of air or free space $=4\pi \times {10}^{-7}$ tesla x m/amp.
The given data says that the relative magnetic permeability of this material is 800. Only ferromagnetic materials have such a high value of $$\mu$$.

Some properties of ferromagnetic material are:
-The cause of magnetism is due to the formation of domains.
-They are strongly attracted to an external magnetic field.
-They get strongly magnetized in the direction of the applied magnetic field.
-The value of magnetic induction is $$B>>B_0$$
-The magnetic susceptibility is positive and high $$x\approx {10}^2$$ and gets converted into paramagnetic materials at Curie temperature.
-The magnetic moment is very high.
-Iron, Cobalt, Nickel, Cadmium, $$F{e}_3{O}_4$$ are some examples of such ferromagnetic materials.
Hence, the material is a ferromagnetic substance.

Note: Based on the behavior of materials in the external magnetic field, they can be categorized as diamagnetic, paramagnetic and ferromagnetic substances whose relative magnetic permeability is ${\mu }_r<1,{\mu }_r>1$ and ${\mu }_r>>1$ respectively.