Question

In electronics it is customary to define the potential of ground (thinking of the earth as a large conductor) as zero. Is this consistent with the fact that the earth has a net electric charge that is not zero?

Short answer

The electric potential of the earth is not zero.

Step-by-step solution

Definition of electric potential

The term electric potential may be defined as the amount of work done by the unit charge in moving from one point to another against an electric field.

Determine whether the net electric charge of the earth is zero or not

The electric potential of the earth can be calculated by the relation:

$V=\frac{Q}{4\mathrm{\pi \epsilon r}}$

From that relation, conclude that the radius of the earth never be infinite, so the electric potential of the earth is also never zero. That’s why the earth has a net electric charge that is not zero.

Hence, the electric potential of the earth is not zero.