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Resistance Formula:
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Electrical resistance is the opposition to the flow of electric current through a conductor. For copper wire, resistance depends on the wire's resistivity, length, and cross-sectional area. Copper is commonly used due to its excellent electrical conductivity.
The calculator uses the resistance formula:
Where:
Explanation: Resistance increases with length and decreases with cross-sectional area. The resistivity is a material property that quantifies how strongly a material opposes the flow of electric current.
Details: Accurate resistance calculation is crucial for electrical circuit design, power transmission systems, and ensuring proper operation of electrical devices. It helps prevent voltage drops, overheating, and ensures efficient energy transfer.
Tips: Enter resistivity in Ω·m (default is 1.68e-8 for copper), length in meters, and cross-sectional area in m². All values must be positive numbers. For circular wires, area can be calculated as π × (diameter/2)².
Q1: What is the typical resistivity of copper?
A: Pure copper at 20°C has a resistivity of approximately 1.68 × 10⁻⁸ Ω·m.
Q2: How does temperature affect copper resistance?
A: Resistance increases with temperature. The temperature coefficient for copper is about 0.00393 per °C.
Q3: How do I calculate area for different wire shapes?
A: For circular wire: A = πr², for rectangular wire: A = width × height, for other shapes use appropriate geometric formulas.
Q4: Why is copper preferred for electrical wiring?
A: Copper has high electrical conductivity, good mechanical strength, corrosion resistance, and is readily available.
Q5: What are common applications of resistance calculations?
A: Electrical system design, power transmission planning, circuit analysis, heating element design, and electrical safety assessments.