Question

Mention two differences between dia. para and ferro magnetism.

Answer 1

PROPERTIESFERROMAGNETIC MATERIALSPARAMAGNETIC MATERIALSDIAMAGNETICStateThey are solid.They can be solid, liquid or gas.They can be solid, liquid or gas.Effect of MagnetStrongly attracted by a magnet.Weakly attracted by a magnet.Weakly repelled by a magnet.Behavior under non-uniform fieldtend to move from low to high field region.tend to move from low to high field region.tend to move from high to low region.Behavior under external fieldThey preserve the magnetic properties after the external field is removed.They do not preserve the magnetic properties once the external field is removed.They do not preserve the magnetic properties once the external field is removed.Effect of TemperatureAbove curie point, it becomes a paramagnetic.With the rise of temperature, it becomes a diamagnetic.No effect.PermeabilityVery highLittle greater than unityLittle less than unitySusceptibilityVery high and positiveLittle greater than unity and positiveLittle less than unity and negativeExamplesIron, Nickel, CobaltLithium, Tantalum, MagnesiumCopper, Silver, Gold

Answer 2

Diamagnetic Material

A material that turns at a right angle to the field by producing a magnetic response opposite to the applied field is called diamagnetic material such as silver, copper, and carbon have permeability’s slightly less than free space (for copper, μr= 0.9999980).

Paramagnetic Material

A material aligning itself with the applied field is called paramagnetic material. Paramagnetic materials such as aluminum and air have permeability’s slightly greater than that of free space (for air μr =1.0000004). The effects of diamagnetic and paramagnetic are negligibly small so that materials possessing these weak phenomena are said to be non-magnetic.

Ferromagnetic Material

Within the paramagnetic class of materials, is a special classification of materials called ferromagnetic material. These materials are strongly attracted to magnets and exhibit Paramagnetism to a phenomenal degree. Ferromagnetic materials such as iron, steel, cobalt and their alloys have relative permeability’s extending into the hundreds and thousands, are said to be magnetic.