What is the definition of a radial circuit in electrical systems?

A radial circuit is defined as a layout in which electrical power is distributed from a single source along one path to various points of use without creating a loop back to that source. This means that the configuration allows current to flow outward from the supply point to devices at the end of the circuit.

In this context, when saying that a radial circuit allows power to flow in one direction, it emphasizes that the circuit does not return to its source, which distinguishes it from other types of circuits that might allow for multiple paths or loops. The design is often seen in lighting and socket systems within residential or commercial installations, where a single supply feeds multiple outlets or fixtures without interconnecting back to the main supply.

Other options describe different configurations: multiple paths suggest a parallel circuit, sourcing from multiple substations implies a ring or interconnected system, and connecting back to its source describes a return path typical of a closed loop. The essence of a radial circuit is its straightforward, linear nature of power flow, pointing to the unidirectional aspect correctly highlighted in the answer chosen.