Question

Suppose a thundercloud with a width of 2.0 𝑘𝑚 and a length of 3.0 𝑘𝑚 hovers at an

altitude of 500 𝑚 over a flat area. The cloud carries a charge of 160 𝐶, and the ground

has no charge.

Problem1: What is the potential difference between the cloud and the ground.

Answer 1

The potential is

$$V=E/H=\sigma/(2\epsilon_0H)=Q/(2\epsilon_0Hab)=3012\text{ V}.$$