1. What Is The Resistance Formula?

The resistance formula calculates the electrical resistance of a conductor based on its material properties and physical dimensions. It provides a fundamental relationship between resistivity, length, and cross-sectional area.

2. How Does The Calculator Work?

The calculator uses the resistance formula:

Where:

• \( R \) — Resistance Overhead AC (Ω)
• \( \rho \) — Resistivity of the material (Ω·m)
• \( L \) — Length of Overhead AC Wire (m)
• \( A \) — Area of Overhead AC Wire (m²)

Explanation: The resistance of a conductor is directly proportional to its resistivity and length, and inversely proportional to its cross-sectional area.

3. Importance Of Resistance Calculation

Details: Accurate resistance calculation is crucial for designing electrical systems, determining power losses, ensuring proper voltage levels, and selecting appropriate conductor sizes for overhead AC transmission lines.

4. Using The Calculator

Tips: Enter resistivity in Ω·m, length in meters, and area in square meters. All values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect the resistivity of a material?
A: Resistivity depends on the material type, temperature, and in some cases, pressure and mechanical stress.

Q2: Why is resistance important in AC transmission systems?
A: Resistance causes power loss in the form of heat (I²R losses) and affects voltage regulation in transmission lines.

Q3: How does temperature affect resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.

Q4: What are typical resistivity values for common conductors?
A: Copper: ~1.68×10⁻⁸ Ω·m, Aluminum: ~2.82×10⁻⁸ Ω·m, Silver: ~1.59×10⁻⁸ Ω·m at 20°C.

Q5: How does conductor shape affect resistance calculation?
A: The formula assumes uniform cross-sectional area along the length. For non-uniform conductors, integration may be required.