A long, hollow, right circular cylinder of inner (outer) radius a (b), and of relative permeability r,

A long, hollow, right circular cylinder of inner (outer) radius a (b), and of relative permeability μr, is placed in a region of initially uniform magnetic-flux density B0 at right angles to the field. Find the flux density at all points in space, and sketch the logarithm of the ratio of the magnitudes of В on the cylinder axis to B0 as a function of log10 μr for a2/b2 = 0.5, 0.1. Neglect end effects.