Capacitance of the Earth
(a) Discuss how the concept of capacitance can also be applied to a single conductor.
(b) Use Eq. (24.1) to show that C = 4πє0R for a solid conducting sphere of radius R.
(c) Use your result in part (b) to calculate the capacitance of the earth, which is a good conductor of radius 6380 km. Compare to typical capacitors used in electronic circuits that have capacitances ranging from 10 pF to 100µF