What does a gauge change of 3 numbers in American Wire Gauge (AWG) represent in terms of electrical conductors?

A gauge change of 3 numbers in the American Wire Gauge (AWG) system is specifically linked to the properties of electrical conductors, particularly resistance and cross-sectional area.

When you move to a wire with a gauge that is 3 numbers lower (for example, going from 12 AWG to 9 AWG), the cross-sectional area of the wire increases significantly. In fact, a decrease of 3 AWG numbers results in the cross-sectional area roughly doubling. Since resistance is inversely proportional to the cross-sectional area, this also means the resistance of the conductor halves in this case. Conversely, if you were to go up 3 AWG numbers (from 12 AWG to 15 AWG), the conductor’s cross-sectional area would be halved, and its resistance would double.

This relationship underlines the importance of gauge sizing in electrical applications where current carrying capacity, heat dissipation, and overall wire performance are critical. Each gauge jump correlates with a specific standard in terms of area and resistance, thus making option A the correct choice.