Neglect end effects. The region between the conductors is air. Ke =1/4*pi*epsilon= 8.98755e9 N m^2/C^2.
A coaxial cable has a charged inner conductor (with charge +4.8 microcoulombs and radius 1.199 mm) and a surrounding oppositely charged conductor (with charge -4.8 microcoulombs and radius 7.405 mm).
a) What is the magnitude of the electric field halfway between the two cylindrical conductors in V/m?
b) What is the capacitance of this cable in nF?