Answer –
(a) At a lower temperature, thermal motion is reduced, and the tendency to disturb the alignment of the dipoles is reduced.
(b) The induced dipole moment is always in the opposite direction as the magnetising field. As a result, the internal motion of the atoms caused by temperature has no effect on the material’s magnetic.
c) Bismuth is a diamagnetic material. As a result, a toroid with a bismith core will have a somewhat smaller field than one with an empty core.
(d) The magnetic field affects the ferromagnetic material’s permeability. Lower fields have more permeability.
(e) The boundary conditions of magnetic fields (B and H) at the interface of two media are used to prove this fundamental statement (which has a lot of practical applications). (When one of the media has a value of >> 1, the field lines almost always intersect this medium.)
(f) Of course. A paramagnetic sample with saturated magnetisation will have the same order of magnetisation, notwithstanding slight changes in the strength of the individual atomic dipoles of two distinct materials. Saturation, on the other hand, necessitates impractically high magnetising fields.