Distinguish between paramagnetic and diamagnetic materials, mentioning at least one example of each.

Paramagnetic Materials: The atoms of these materials have permanent magnetic dipoles. Individual dipoles are oriented in random fashion therefore resultant magnetic field is negligible or zero. For these materials relative permeability is slightly greater than unity and this is independent of magnetizing force. In presence of external magnetic field, paramagnetic materials find weakly magnetised into the field direction and the susceptibility is specified by

 χ = C /T , here C is a curie constant and T is the temperature. Examples are: Chromium chloride, manganese sulphate, chromium oxide and air.

Diamagnetic Materials: These are the materials whose atoms do not carry permanent magnetic dipoles. When an external magnetic field is applied to a diamagnetic material, this induces a magnetization into the direction reverse to the applied field intensity. For such materials the relative permeability is negative. These are hardly utilized as magnetic material in electrical/electronic engineering applications. Examples are: Aluminium oxide, copper, barium chloride and gold.