1. Household circuits are often wired with two different widths of wires: 12-gauge and 14-gauge. The 12-gauge wire has a diameter of 1/12 inch while the 14-gauge wire has a diameter of 1/14 inch. Thus, 12-gauge wire has a wider cross section than 14-gauge wire. A 20-Amp circuit used for wall receptacles should be wired using 12-gauge wire and a 15-Amp circuit used for lighting and fan circuits should be wired using 14-gauge wire. Explain the physics behind such an electrical code.

Question

Physics

Oswaldo Lewis

3 December, 22:57

1. Household circuits are often wired with two different widths of wires: 12-gauge and 14-gauge. The 12-gauge wire has a diameter of 1/12 inch while the 14-gauge wire has a diameter of 1/14 inch. Thus, 12-gauge wire has a wider cross section than 14-gauge wire. A 20-Amp circuit used for wall receptacles should be wired using 12-gauge wire and a 15-Amp circuit used for lighting and fan circuits should be wired using 14-gauge wire. Explain the physics behind such an electrical code.

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Answers (2)

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Kayley Allen · Answer 1

This formula R = ρL/A

Where R = resistance of wire, ρ = resistivity of the wire and A = area of the wire. Shows there is an inverse relationship between Resistance and Area of the wire.

Explanation:

A simple way to explain the physics behind such an electrical code is to compare the flow of current through wires to the flow of water through pipes, they are similar in any respect. The resistance to the flow of current in an electric circuit is similar to the frictional experienced by water when flowing through water pipes. Just as water will flow easily with little resistance through a water pipe with the larger cross-sectional area than one with a smaller cross-sectional area, in the same way, wires with larger cross-sectional area will allow the flow of larger amount of current compared to wires with smaller cross-sectional area assuming all other variables are the same.

From the formula R = ρL/A

Where R = resistance of wire, ρ = resistivity of the wire and A = area of the wire

We can see that the resistance and area of the wire have an inverse relationship. An increase in the area of the wire will lead to a decrease in the resistance of the wire.

Leia Khan · Answer 2

It can be said that a 12 gauge wire is wider than a 14 gauge wire, this means that it will have less resistance. This means that it allows the electric charge to flow at a much higher speed, allowing for a higher current.

Explanation:

As a conclusion, the 12 gauge wire is used in circuits that find 20A fuse protection. However, the 14 gauge wire can withstand less electrical current because it has a higher resistance. These 14 gauge cables are used in circuits that meet 15A fuse protection.