A long, straight wire that has a radius of 1.00 mm is coated with an insulating ferromagnetic material that has a thickness of 3.00 mm and a relative magnetic permeability of 400. The coated wire is in air and the wire itself is nonmagnetic. The wire carries a current of 40.0 A.
a) Discover the magnetic field in the region occupied with the inside of the wire as a function of the perpendicular distance, r, from the central axis of the wire.
b) Discover the magnetic field in the region occupied by the inside of the ferromagnetic material as a function of the perpendicular distance, r, from the central axis of the wire.
c) Discover the magnetic field in the region surrounding the wire and coating as a function of the perpendicular distance, r, from the central axis of the wire.
d) What should the magnitudes and directions of the amperian currents be on the surfaces of the ferromagnetic material to account for the magnetic fields observed?