On the basis of magnetic properties, different materials have been classified into three categories
(i) `text(Diamagnetic substance)` These substances when placed in an external magnetic field, then acquire feeble magnetism opposite to the direction of the magnetic field. e.g. `Bi, Zn, Au, NaCI, H_2O`, etc.
(ii) `text(Paramagnetic substance)` These substances when placed in an external magnetic field, then acquire feeble magnetism in the direction of the magnetic field.
e.g. `AI, Na, Pt, Mn, CuCl_2 , O_2`, etc.
(iii) `text (Ferromagnetic substance)` These substances when placed in an external magnetic field are strongly magnetised in the direction of the field.
e.g. `Fe, Ni, Co, Fe_2O_ 3` , etc.
`text(Curie's law)`
According to curie's Law, the magnetic susceptibility of paramagnetic substance is inversely proportional to the absolute temperature. i.e.
` chi alpha 1/T`
`text(Curie Temperature)`
Above a certain temperature the substance loses its ferromagnetic character and begins to behave as a paramagnetic substance. This particular temperature is called the curie temperature of the substance.
`text(Magnetic Flux)`
It is defined as the total number of magnetic lines of force passing normally through any surface. If surface of area A is placed perpendicular to uniform magnetic field B. Then, magnetic flux `phi = BA`. Its unit is `Wb` (weber) or `kg-m^2 // s^2 A`. If a plane is parallel to the magnetic field, then no flux link will pass through it and magnetic flux link with coil will be zero. If the coil is rotated through `90°` in the magnetic field, then magnetic flux linked with the coil is zero.
On the basis of magnetic properties, different materials have been classified into three categories
(i) `text(Diamagnetic substance)` These substances when placed in an external magnetic field, then acquire feeble magnetism opposite to the direction of the magnetic field. e.g. `Bi, Zn, Au, NaCI, H_2O`, etc.
(ii) `text(Paramagnetic substance)` These substances when placed in an external magnetic field, then acquire feeble magnetism in the direction of the magnetic field.
e.g. `AI, Na, Pt, Mn, CuCl_2 , O_2`, etc.
(iii) `text (Ferromagnetic substance)` These substances when placed in an external magnetic field are strongly magnetised in the direction of the field.
e.g. `Fe, Ni, Co, Fe_2O_ 3` , etc.
`text(Curie's law)`
According to curie's Law, the magnetic susceptibility of paramagnetic substance is inversely proportional to the absolute temperature. i.e.
` chi alpha 1/T`
`text(Curie Temperature)`
Above a certain temperature the substance loses its ferromagnetic character and begins to behave as a paramagnetic substance. This particular temperature is called the curie temperature of the substance.
`text(Magnetic Flux)`
It is defined as the total number of magnetic lines of force passing normally through any surface. If surface of area A is placed perpendicular to uniform magnetic field B. Then, magnetic flux `phi = BA`. Its unit is `Wb` (weber) or `kg-m^2 // s^2 A`. If a plane is parallel to the magnetic field, then no flux link will pass through it and magnetic flux link with coil will be zero. If the coil is rotated through `90°` in the magnetic field, then magnetic flux linked with the coil is zero.