Three identical bars A, B and C are made of different magnetic materials. When kept in a uniform magnetic field, the field lines around them look as given in the figure . Make the correspondence of these bars with their material being diamagnetic (D), ferromagnetic (F) and paramagnetic (P) .

Answer the following questions: 
(a) Why does a paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled? 
(b) Why is diamagnetism, in contrast, almost independent of temperature?
(c) If a toroid uses bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty? 
(d) Is the permeability of a ferromagnetic material independent of the magnetic field? If not, is it more for lower or higher fields? 
(e) Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why? 
(f) Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?