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Resistance Formula:
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Electrical resistance is a measure of the opposition to the flow of electric current in a conductor. For copper wires, resistance depends on the material's resistivity, length of the wire, and its cross-sectional area.
The calculator uses the resistance formula:
Where:
Explanation: The resistance increases with length and decreases with cross-sectional area, following the fundamental relationship defined by the material's resistivity.
Details: Calculating wire resistance is crucial for electrical system design, power transmission efficiency, voltage drop analysis, and ensuring proper circuit operation without excessive power loss.
Tips: Enter resistivity in Ω·m (copper default is 1.68×10⁻⁸), length in meters, and cross-sectional area in square meters. All values must be positive numbers.
Q1: Why is copper commonly used for electrical wiring?
A: Copper has low resistivity (1.68×10⁻⁸ Ω·m), excellent conductivity, good mechanical strength, and resistance to corrosion, making it ideal for electrical applications.
Q2: How does wire diameter affect resistance?
A: Larger diameter means larger cross-sectional area, which significantly reduces resistance. Doubling the diameter reduces resistance to one-fourth.
Q3: What is the typical resistance range for copper wires?
A: For standard household wiring (2.5mm², 10m length), resistance is approximately 0.067Ω. Very low resistance is desirable to minimize power loss.
Q4: Does temperature affect copper wire resistance?
A: Yes, copper resistance increases with temperature. The temperature coefficient for copper is about 0.00393 per °C at 20°C.
Q5: When is this calculation most important?
A: Critical for long cable runs, high-current applications, precision instruments, and situations where voltage drop must be minimized.