What typically comprises a three-core and earth cable and its use?

• A. Usually three insulated conductors plus an earth core; used for two-way lighting or certain domestic circuits; color coding matches current standards.
• B. A pair of wires plus a separate earth conductor used for single-phase circuits.
• C. A flexible cable with four cores used in motor control.
• D. A coaxial cable used for signal transmission.

Answer: (C)

Three-core and earth cable contains three insulated conductors plus an earth conductor. This setup is used for circuits that need to be controlled from more than one location, such as two-way lighting. The three insulated cores carry the live conductors (often designated L1, L2 and a common) between two switches and the light, while the earth provides safety grounding. In normal practice, the neutral stays at the ceiling rose or light fitting and isn’t carried to the switch in this configuration. Color coding helps identify each conductor (older schemes used red, yellow, blue; newer ones use brown, black, grey). This arrangement is specific to multi-location control scenarios and isn’t a four-core cable, which would be used for more complex control or different equipment like certain motor circuits.