Question

Show diagrammatically the behaviour of magnetic field lines in the presence of (i) paramagnetic and (ii) diamagnetic substances. How does one explain this distinguishing feature?

Answer 1

(i) The behaviour of magnetic field lines in the presence of a paramagnetic substance is shown below :



(ii) The behaviour of magnetic field lines in the presence of a diamagnetic substance is shown below :



This distinguishing feature is because of the difference in their relative permeability. Relative permeability is the ratio of the permeability of a specific medium to the permeability of free space. The relative permeability of diamagnetic substance is less than 1, so the magnetic lines of force do not prefer passing through the substance whereas the relative permeability of paramagnetic substance is greater than 1, so the magnetic lines of force prefer passing through the substance.