NCCER Electrical Certification Practice Test 2025 - Free Electrical Certification Practice Questions and Study Guide

The most commonly used wire for residential lighting circuits in the U.S. is 12 AWG copper. This wire gauge is suitable for handling 20 amps of current, which is the standard rating for most lighting circuits in homes. The 12 AWG copper wire provides a good balance of current-carrying capacity and flexibility, making it ideal for a variety of applications in residential wiring.

Using 12 AWG wire helps to prevent excessive voltage drop and ensures that the circuit can safely handle the electrical load typically imposed by standard lighting fixtures without risk of overheating. Additionally, copper wire is favored for its excellent conductivity, durability, and relatively lightweight properties, which facilitate easier handling and installation.

While other wire sizes, such as 14 AWG copper, are indeed used for lighting circuits, they are generally designated for circuits with a maximum of 15 amps. The use of 10 AWG aluminum and 8 AWG copper wire is typically reserved for larger loads or specific applications where higher current capacity is required, such as for heavy appliances or sub-panels, thus making them less common for standard residential lighting circuits.