Given two finite parallel planes of length l, width w, area A = lw, and separation d, one with total surface charge and the other with , the electric field can be found in cgs (ignoring edge effects) from

(1)

so

(2)

The capacitance (ignoring edge effects) then follows from the equation for voltage

(3)

as

(4)

If a current I were allowed to flow, the magnetic field is easily found as

(5)

where c is the speed of light, so

(6)

The inductance would then follow from

(7)

as