1. What is Wire Resistance?

Wire resistance is the opposition to the flow of electric current through a conductor. It depends on the material's resistivity (ρ), the length of the wire (L), and its cross-sectional area (A).

2. How Does the Calculator Work?

The calculator uses the resistance equation:

Where:

• \( R \) — Resistance in ohms (Ω)
• \( \rho \) — Resistivity of the material (ohm·m)
• \( L \) — Length of the wire (meters)
• \( A \) — Cross-sectional area (m²)

Explanation: Resistance increases with longer wires and higher resistivity materials, but decreases with larger cross-sectional areas.

3. Importance of Resistance Calculation

Details: Calculating wire resistance is essential for designing electrical circuits, selecting appropriate wire gauges, and ensuring proper voltage delivery to components.

4. Using the Calculator

Tips: Enter resistivity in ohm·m (e.g., copper is 1.68×10⁻⁸ Ω·m), length in meters, and cross-sectional area in m². All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical resistivity values?
A: Copper: 1.68×10⁻⁸ Ω·m, Aluminum: 2.65×10⁻⁸ Ω·m, Silver: 1.59×10⁻⁸ Ω·m, Gold: 2.44×10⁻⁸ Ω·m.

Q2: How does temperature affect resistance?
A: Resistance generally increases with temperature for metals (positive temperature coefficient).

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

Q4: How do I calculate area for round wires?
A: Area = π × (radius)² = π × (diameter/2)². For AWG wires, consult standard tables.

Q5: Why does thicker wire have less resistance?
A: More cross-sectional area provides more paths for electrons to flow, reducing resistance.