1. What Is Electrical Resistance?

Electrical resistance is a measure of the opposition to the flow of electric current through a conductor. For copper wire, resistance depends on the wire's dimensions and the material's inherent resistivity.

2. How Does The Calculator Work?

The calculator uses the resistance formula:

Where:

• \( R \) — Electrical resistance (ohms)
• \( \rho \) — Resistivity of copper (1.68×10⁻⁸ ohm·m)
• \( L \) — Length of wire (meters)
• \( A \) — Cross-sectional area (square meters)

Explanation: Resistance increases with wire length and decreases with cross-sectional area. Copper's low resistivity makes it an excellent conductor.

3. Importance Of Resistance Calculation

Details: Accurate resistance calculation is crucial for electrical circuit design, voltage drop analysis, power loss estimation, and selecting appropriate wire gauges for specific applications.

4. Using The Calculator

Tips: Enter length in meters and cross-sectional area in square meters. For circular wires, area can be calculated as π × (diameter/2)². All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is copper used for electrical wiring?
A: Copper has low resistivity (1.68×10⁻⁸ ohm·m), high conductivity, good mechanical strength, and excellent corrosion resistance.

Q2: How does temperature affect copper resistance?
A: Copper resistance increases with temperature. The temperature coefficient for copper is approximately 0.00393 per °C at 20°C.

Q3: What is the difference between resistance and resistivity?
A: Resistivity is an intrinsic property of the material, while resistance depends on both the material and the conductor's dimensions.

Q4: How do I calculate area for different wire shapes?
A: For circular wires: π × r²; for rectangular wires: width × height; for square wires: side².

Q5: What are typical resistance values for copper wires?
A: Resistance varies greatly with wire gauge. For example, 10 AWG copper wire has about 3.277 ohms per 1000 meters at 20°C.