A small solid conductor with radius a is supported by insulating, nonmagnet- ic disks on the axis of a thin-walled tube with inner radius b. The inner and outer conductors carry equal currents / in opposite directions. In the figure, O the size of the inner conductor has been exaggerated for clarity, and its con- tribution to the magnetic flux may be neglected. a a) Use Ampere's Law to find the magnetic field at any point in the volume be- tween the conductors. R b b) Write the expression for the magnetic flux do, through a narrow strip of length / parallel to the axis, of width dR, at a distance R from the axis of the cable and lying in a plane containing the axis. c) Integrate your expression from part b) over the space between the two conductors to find the total flux produced by a current / in the central con- ductor. d) Calculate the inductance of a length / of the cable. . e) Calculate the energy stored in the magnetic field for a length / of the cable