For a 120-volt, 15-ampere circuit, which conductor size is typically used?

In a 120-volt, 15-ampere circuit, the conductor size that is typically used is 14 AWG. This is based on the National Electrical Code (NEC) guidelines, which recommend 14 AWG wire for circuits with a maximum load of 15 amperes.

Using a 14 AWG conductor ensures that the wire can safely handle the current without overheating, which is crucial for preventing fire hazards. Additionally, 14 AWG wire has a sufficient voltage drop allowance for shorter runs, making it suitable for residential wiring applications where 120-volt circuits are common.

The other conductor sizes mentioned are either larger than necessary or too small for this application. A larger gauge like 12 AWG is used for 20-amp circuits, while smaller gauges such as 16 AWG and 14 AWG are typically reserved for lesser amperages. Therefore, 14 AWG is the correct and safe choice for a 15-amp circuit.