Red Seal Electrician Practice

Wiring and componentsQuestion 425 of 1506

A single-phase three-wire supply is made by connecting two 120 V sources. How are they connected?

In parallel, with the neutral taken from the positive side
In series aiding, with the neutral taken from the common point
In series opposing, with the neutral taken from the outer point
In parallel, with two line conductors

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Correct answer: In series aiding, with the neutral taken from the common point

The common point between the sources is the neutral conductor.

Source: Electrical Fundamentals Competency (Industry Training Authority of BC), 7.4: Three-wire Power Supply System

Practice wiring and components

Questions last reviewed: 18 October 2026

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