G0B02 - According to the National Electrical Code, what is the minimum wire size that may be used safely for wiring with a 20-ampere circuit breaker?

Question

According to the National Electrical Code, what is the minimum wire size that may be used safely for wiring with a 20-ampere circuit breaker?

Answer Options

  • A) AWG number 20
  • B) AWG number 16
  • C) AWG number 12
  • D) AWG number 8

Correct Answer: C


Explanation

The National Electrical Code (NEC) Article 310 specifies the minimum wire size for a given circuit breaker or fuse amperage to prevent the wire from overheating and causing a fire. This is a critical electrical safety standard.

For a circuit protected by a 20-ampere circuit breaker, the NEC requires a minimum wire size of AWG number 12. A smaller wire size is permissible only for lower current; for example, AWG number 14 is only permitted for a 15-ampere circuit. Using a smaller wire on a higher-rated breaker is a major fire hazard.


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