Home
Back
Resistance Formula:
| From: | To: |
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 transmission efficiency and voltage drop.
The calculator uses the resistance formula:
Where:
Explanation: The resistance of a conductor is directly proportional to its length and resistivity, and inversely proportional to its cross-sectional area.
Details: Accurate resistance calculation is crucial for determining power losses, voltage drop, and efficiency in electrical transmission systems. It helps in proper system design and material selection for overhead AC lines.
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.
Q1: What factors affect resistance in overhead AC lines?
A: Resistance is affected by material type (resistivity), conductor length, cross-sectional area, temperature, and frequency of the AC current.
Q2: Why is resistance important in power transmission?
A: Resistance causes power losses (I²R losses) and voltage drop, which affect transmission efficiency and system performance.
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 AC resistance differ from DC resistance?
A: AC resistance is typically higher than DC resistance due to skin effect and proximity effect in alternating current systems.