A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment $$\mu $$ is given by

Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show

Curie temperature above which

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by $$\mu $$_d, $$\mu $$_p and $$\mu $$_f respectively, then