Question

There is a naturally occurring electric field near the surface of the Earth whose magnitude is 80√pi V/m. How much energy is stored per cubic meter in this field?

Answer 1

The energy of the electric field is given by:
Energy = ε₀E²/2; where ε₀ is the permittivity of free space. Thus:

Energy = 8.85 x 10⁻¹² x (80√π)²/2
Energy = 8.9 x 10⁻⁸ Joules per cubic meter