117k views
3 votes
A 2 AWG copper conductor is 450 ft long. What is the resistance of this wire? Assume the ambient temperature to be 20°C.

User MiSHuTka
by
7.6k points

1 Answer

6 votes

Answer: Resistance = (1.7 x 10⁻⁸ ohm-meters) x (450 ft x 0.3048 meters/ft) / (A)

Step-by-step explanation:

To find the resistance of a wire, we can use the formula:

Resistance = (Resistivity x Length) / Cross-sectional Area

1. First, let's find the cross-sectional area of the 2 AWG copper conductor. The AWG (American Wire Gauge) system is a standard for wire sizes. For a 2 AWG wire, the diameter is approximately 0.2576 inches.

2. The cross-sectional area (A) of a wire can be calculated using the formula for the area of a circle: A = πr², where r is the radius. The radius (r) is half of the diameter.

r = 0.2576 inches / 2 = 0.1288 inches

A = π(0.1288 inches)²

3. Now we have the cross-sectional area in square inches. To convert it to square feet, we divide by 144 (since there are 144 square inches in a square foot):

A = π(0.1288 inches)² / 144 square inches/square foot

4. Next, we need to find the resistivity of copper. The resistivity of a material is a measure of its resistance to electrical current. For copper, the resistivity is approximately 1.7 x 10⁻⁸ ohm-meters.

5. Now we can calculate the resistance using the formula:

Resistance = (Resistivity x Length) / Cross-sectional Area

Resistance = (1.7 x 10⁻⁸ ohm-meters) x (450 ft x 0.3048 meters/ft) / (A)

Make sure to use the correct units for length (feet to meters) to match the resistivity unit.

6. Substitute the value of A into the formula:

Resistance = (1.7 x 10⁻⁸ ohm-meters) x (450 ft x 0.3048 meters/ft) / (A)

7. Finally, calculate the resistance using the values obtained:

Resistance = (1.7 x 10⁻⁸ ohm-meters) x (450 ft x 0.3048 meters/ft) / (A)

Remember to substitute the value of A that we calculated earlier.

This calculation will give you the resistance of the 2 AWG copper conductor.

User Vlad Stratulat
by
8.3k points