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Resistance Formula:
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The resistance of a conductor formula calculates the electrical resistance of a material based on its physical properties and dimensions. This fundamental relationship in electrical engineering helps determine how much a material opposes the flow of electric current.
The calculator uses the resistance formula:
Where:
Explanation: The formula shows that resistance is directly proportional to the material's resistivity and length, and inversely proportional to its cross-sectional area.
Details: Accurate resistance calculation is crucial for designing electrical circuits, selecting appropriate wire sizes, preventing overheating, and ensuring efficient power transmission in electrical systems.
Tips: Enter resistivity in Ω·m, length in meters, and cross-sectional area in square meters. All values must be positive numbers greater than zero for accurate calculation.
Q1: What is resistivity and how is it determined?
A: Resistivity is an intrinsic property of materials that quantifies how strongly they resist electric current. It's measured experimentally and varies with temperature.
Q2: Why does resistance increase with length?
A: Longer conductors provide more obstacles for electrons to overcome, increasing the total resistance proportionally with length.
Q3: Why does resistance decrease with larger cross-sectional area?
A: Larger cross-sectional areas provide more pathways for electrons to flow, reducing the overall resistance inversely with area.
Q4: How does temperature affect resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.
Q5: What are typical resistivity values for common materials?
A: Copper: 1.68×10⁻⁸ Ω·m, Aluminum: 2.82×10⁻⁸ Ω·m, Silver: 1.59×10⁻⁸ Ω·m, Iron: 1.0×10⁻⁷ Ω·m.