Consider the Earth and a cloud layer 700 meter above the planet to be the plates of a parallel-plate capacitor.
(a) If the cloud layer has an area of 4.0 km2 = 4000000 m2, determine what is the capacitance?
F
(b) If an electric field strength greater than 3 x 106 N/C causes the air to break down and conduct charge (lightning), obtain the maximum charge the cloud can hold?
C