Final answer:
The voltage rating of communication cables and wires is determined based on the maximum voltage they can handle without damage.
Step-by-step explanation:
The voltage rating of communication cables and wires is determined based on the maximum voltage that they can handle without damaging the insulation or causing electrical breakdown. It is important to choose cables and wires with a voltage rating that meets or exceeds the maximum voltage that will be present in the system. For example, in power transmission lines, voltages ranging from 120 to 700 kV are used to transmit power over long distances.