A long coaxial cable consists of two thin walled concentric conducting cylinders with radii a and b. The inner cylinder carries a current I (out of page) and the outer provides the return path for that current. The current creates a magnetic field between the two cylinders.
Find:
a) The magnetic energy density in the same region.
b) The total energy for a length l of the cable is.
c) What is the energy stored per unit length of the cable if a = 1.2mm, b=3.5mm, and I=2.7A?
