What is the smallest wire size permitted for general wiring?

• A. No. 12
• B. No. 14
• C. No. 16
• D. No. 18

Answer: (B)

The smallest wire size permitted for general wiring is No. 14. In residential electrical systems, No. 14 gauge wire is commonly used for branch circuits that carry 15 amps. This size is generally recognized as the minimum for typical lighting and receptacles in homes.

Using a larger size like No. 12 is acceptable and indeed more robust for carrying a higher amperage, but it is not the minimum required. Smaller sizes such as No. 16 and No. 18 do not meet the necessary current carrying capacity for general wiring applications defined by the National Electrical Code (NEC) and would not safely handle normal household loads. Therefore, No. 14 strike the right balance of safety, effectiveness, and compliance with electrical codes for general wiring purposes.