1. What is Resistance Overhead AC?

Resistance Overhead AC is defined as the property of the wire or line that opposes the flow of current through it in an overhead AC transmission system. It is a crucial parameter in electrical engineering that affects power loss and voltage drop in transmission lines.

2. How Does the Calculator Work?

The calculator uses the 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 essential for determining power losses, voltage drops, and efficiency in AC transmission systems. It helps in proper system design and material selection for overhead 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.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect resistivity?
A: Resistivity depends on the material type and temperature. It increases with temperature for most conductors.

Q2: Why is resistance important in AC systems?
A: Resistance causes power loss (I²R loss) and voltage drop, affecting system efficiency and performance.

Q3: How does wire area affect resistance?
A: Larger cross-sectional area reduces resistance, allowing more current flow with less power loss.

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

Q5: Does AC resistance differ from DC resistance?
A: Yes, AC resistance is typically higher due to skin effect and proximity effect in alternating current systems.