1. What is Copper Wire Resistance?

The resistance of a copper wire depends on its length, cross-sectional area, and the resistivity of copper. It determines how much the wire opposes the flow of electric current.

2. How Does the Calculator Work?

The calculator uses the resistance formula:

Where:

• \( R \) — Resistance in ohms (Ω)
• \( 1.68 \times 10^{-8} \) — Resistivity of copper (Ω·m)
• \( L \) — Length of wire (meters)
• \( A \) — Cross-sectional area (m²)

Explanation: The resistance increases with longer wires and decreases with thicker wires (larger cross-sectional area).

3. Importance of Resistance Calculation

Details: Calculating wire resistance is crucial for designing electrical circuits, selecting appropriate wire gauges, and minimizing power losses.

4. Using the Calculator

Tips: Enter length in meters and cross-sectional area in square meters. For circular wires, area = πr² where r is radius in meters.

5. Frequently Asked Questions (FAQ)

Q1: Why is copper used for electrical wiring?
A: Copper has low resistivity (1.68×10⁻⁸ Ω·m), is ductile, and resists corrosion, making it ideal for electrical conductors.

Q2: How does temperature affect resistance?
A: Copper's resistance increases with temperature (positive temperature coefficient). The calculator assumes room temperature (20°C).

Q3: What's the difference between resistance and resistivity?
A: Resistivity is a material property (Ω·m), while resistance depends on both material and geometry (Ω).

Q4: How do I find the area for different wire shapes?
A: For circular wires: πr². For rectangular wires: width × thickness. For American Wire Gauge (AWG), consult conversion tables.

Q5: What's the practical significance of this calculation?
A: Helps determine voltage drop, power loss (I²R), and appropriate wire size for given current requirements.