A _____-amp breaker should supply a minimum #12 conductor.

• A. 20
• B. 10
• C. 15
• D. 40

Answer: (A)

A 20-amp breaker should supply a minimum #12 conductor because, according to the National Electrical Code (NEC), a #12 wire is rated for a maximum of 20 amps. Using the correct size conductor is essential for safety, as it ensures the wire can handle the electrical load without overheating.

Choosing a conductor that is too small for the current it carries can lead to dangerous overheating and potential fire hazards. In residential electrical systems, a #12 wire is commonly used for general-purpose circuits, including outlets for kitchen appliances and other equipment that may draw more current.

The other options, such as a 10-amp breaker, would require a smaller #14 conductor, and a 15-amp breaker is appropriately paired with a #14 conductor as well. A 40-amp breaker would necessitate a much larger conductor, typically #8 or larger, depending on the installation conditions. Therefore, the pairing of a 20-amp breaker with a #12 conductor maintains both compliance with code and ensures safe operation.