A storm cloud $($circular in cross$-$section, $30$ km in diameter$)$ is at

$$V $=1108$ V relative to the

ground. The base of the storm clouds are $10$ km high. Think of this system as a $$capacitor$.$

a$.$ What is the $$capacitance$?$

b$.$ How much energy is stored in this $$capacitor$?$

c$.$ Now determine how much magnetic energy is stored in this same volume, due to

the Earth$$s magnetic field.

d$.$ How do the results compare? Are the results surprising?