Answer:

The electric potential of the neutral wire in a mains supply cable is zero volts.

In an AC circuit, the neutral wire serves as a return path for the passage of electricity. The neutral wire carries no current, but the AC circuit is incomplete without it. The neutral wire in any electrical circuit redirects the flow of the electrical current back to its originating point. In a three-phase circuit, the neutral wire or neutral point is the node where the sum of current is zero, also known as the zero potential point. The earth and the neutral point in an AC circuit must have the same potential; ideally, the potential difference between the two should be zero.