Problem 2 A coaxial cable consists of a solid inner conductor of radius a, surrounded by a concentric cylindrical tube of inner radius b and outer radius c. The conductors carry equal and opposite currents I distributed uniformly across their cross-sections. a) Determine the magnitude and direction of the magnetic field at a distance r away from the central axis. Consider (i) r < a; (ii) a <r<b; (iii) b<r<c; (iv) r > c. b lo To b) Sketch a graph of the magnitude of the magnetic fields as a function of the distance r away from the axis. Problem 3 Consider an infinitely long, cylindrical conductor of radius R carrying a current with a non- uniform current density centre of the cylinder. = ar², where a is a constant and r is the distance from the (a) Find the magnetic field everywhere (i.e. inside and outside the conductor) in terms of Ho, a,r and R. (b) Plot the magnitude of the magnetic field as a function of r.