A very long coaxial cable consists of a solid cylindrical inner conductor of radius 4mm , surrounded by an outer cylindrical conductor with inner radius 7mm , and outer radius 9.5mm . The region between the two conductors is filled with a waxlike insulating material to keep the conductors from touching each other. The inner conductor carries a current 2.55A , into the page, while the outer conductor carries a current 2.05A , out of the page.
A) Use Ampère's law to derive an expression for the magnetic field as a function of r (the distance from the central axis) at points between the two conductors (R1
B) Use Ampère's law to derive an expression for the magnetic field as a function of r (the distance from the central axis) at points inside the outer conductor (R2i
C) Use Ampère's law to derive an expression for the magnetic field as a function of r (the distance from the central axis) at points outside the outer conductor (r>R2o ). Use this expression to find the magnetic field at 14.9mm .