The radii of the inner and outer conductors of a coaxial cable are 2 cm and 5 cm, respecti...

The radii of the inner and outer conductors of a coaxial cable are 2 cm and 5 cm, respectively, and the insulating material between them has a relative permittivity of 4. The charge density on the outer conductor is ρℓ = 10–4 (C/m). Use the expression for E derived in Example to calculate the total energy stored in a 20-cm length of the cable.

Expression