Which statement is correct about wire gauge current capacity?

• A. A 1 mm diameter wire can be replaced with 20 gauge wire.
• B. A 22 gauge wire can carry more current than an 18 gauge wire.
• C. Both statements are correct.
• D. Neither statement is correct.

Answer: (B)

The main idea here is that current-carrying ability rises with the conductor’s cross-sectional area: thicker wires (lower gauge numbers) can carry more current before overheating than thinner ones (higher gauge numbers).

A wire around 1 mm in diameter is similar to a thicker gauge (roughly 18 AWG). A 20 gauge wire is thinner than that, so it would carry less current. Replacing a thicker conductor with a thinner one reduces the amount of current that can safely pass without overheating.

Likewise, a 22 gauge wire is even thinner than 18 AWG, so it carries even less current. So the statement that a 22 gauge wire can carry more current than an 18 gauge wire isn’t correct.

Neither statement is correct. In practice, you choose a wire with a larger cross-section if you need to carry more current, and you consult ampacity charts that factor in insulation and temperature conditions to ensure safe operation.