Final answer:
True, an extra-low voltage (ELV) power circuit may use copper conductors smaller than No.14 AWG because ELV systems operate at lower safety risk levels and carry less current (A).
Step-by-step explanation:
The statement 'An extra-low voltage power circuit may be wired with copper conductors smaller than No.14 AWG' is true. Extra-low voltage (ELV) systems operate at voltage levels that typically pose less of a hazard, allowing the use of smaller wires. The American Wire Gauge (AWG) is a standardized system where the larger the gauge number, the smaller the diameter of the wire. Standard household wiring uses wires ranging from 10-gauge to 14-gauge, but in the case of ELV circuits, the requirements for the amount of current and the risk of electric shock are reduced, permitting the use of wires smaller than No.14 AWG.
It's important to note that the current-carrying capacity of a wire is determined by its diameter, with larger diameters carrying more current. Since ELV circuits carry less current, they do not require the larger diameters associated with higher-gauge wires.