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Electrical Resistance Formula:
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The electrical resistance formula R = ρ × L / A calculates the resistance of a conductor based on its material properties and physical dimensions. It provides a fundamental relationship between resistivity, length, cross-sectional area, and electrical resistance.
The calculator uses the electrical resistance formula:
Where:
Explanation: The formula shows that resistance is directly proportional to both resistivity and length, but inversely proportional to cross-sectional area.
Details: Accurate resistance calculation is crucial for designing electrical circuits, selecting appropriate wire gauges, predicting voltage drops, and ensuring proper functioning of 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.
Q1: What is resistivity?
A: Resistivity is an intrinsic property of materials that quantifies how strongly they oppose electric current. Different materials have different resistivity values.
Q2: How does temperature affect resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.
Q3: What are typical resistivity values?
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.
Q4: Why is cross-sectional area important?
A: Larger cross-sectional areas provide more paths for electron flow, resulting in lower resistance.
Q5: Can this formula be used for all materials?
A: This formula applies to homogeneous materials with uniform cross-section. It may not be accurate for complex geometries or materials with varying resistivity.