Magnetism and Matter
13.0 Magnetic of Material
13.0 Magnetic of Material
To describe the magnetic properties of materials, following terms are required
(i) Magnetic Permeability It is the ability of a material to permit the passage of magnetic lines of force through it.
Magnetic permeability $\left( \mu \right) = \frac{B}{H}$
where $B$ is magnetic induction and $H$ is magnetising force or magnetic intensity.
(ii) Magnetising Force or Magnetic Intensity The degree up to which a magnetic field can magnetise a material is defined in terms of magnetic intensity.
Magnetic intensity $\left( H \right) = \frac{B}{\mu }$
(iii) Intensity of Magnetisation The magnetic dipole moment developed per unit volume of the material is called intensity of magnetisation.
Intensity of magnetisation $\left( I \right) = \frac{M}{V} = \frac{m}{A}$
where $V =$ volume and $A =$ area of cross-section of the specimen.
Magnetic induction $B = ?o (H + I)$
(iv) Magnetic Susceptibility$(?m)$ The ratio of the intensity of magnetisation $(1)$ induced in the material to the magnetising force $(H)$ applied, is called magnetic susceptibility.
Magnetic Susceptibility $\left( {\chi m} \right) = \frac{I}{H}$
$[$Relation between Magnetic Permeability and Susceptibility is given by $? = ?o (1 + ?m) ]$
