What is the minimum copper wiring size that should be used for carrying 120 volts?

• A. 10 awg
• B. 12 awg
• C. 14 awg
• D. 16 awg

Answer: (C)

The minimum copper wiring size for carrying 120 volts is 14 AWG (American Wire Gauge). This wire size is appropriate for general residential circuits, which includes typical lighting and receptacle circuits that are protected by a 15-amp circuit breaker.

Using 14 AWG wire allows for a safe carrying capacity of up to 15 amps, which is standard for 120-volt circuits in many residential applications. This ensures that the wire can handle the current without overheating and is compliant with the National Electrical Code (NEC) requirements. In contrast, larger wire sizes, like 10 AWG and 12 AWG, are often used for higher current applications and can handle more amperage, but they are not necessary for circuits that only require 15 amps. Smaller wire sizes, such as 16 AWG, do not meet the safety requirements for these applications, as they would not be able to safely carry the expected current load. Using wires that are too small can lead to excessive heat buildup and increase the risk of insulation failure or even electrical fires.