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Electrical Resistance Formula:
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Electrical resistance is a measure of how strongly a material opposes the flow of electric current. For wires, resistance depends on the material's resistivity, the wire's length, and its cross-sectional area according to the fundamental formula R = ρL/A.
The calculator uses the electrical resistance formula:
Where:
Explanation: Resistance increases with length (more collisions for electrons) and decreases with cross-sectional area (more pathways for electron flow).
Details: Calculating wire resistance is crucial for electrical system design, determining voltage drop, selecting appropriate wire gauges, and ensuring efficient power transmission in circuits and electrical installations.
Tips: Enter resistivity in Ω·m (e.g., copper: 1.68×10⁻⁸ Ω·m), length in meters, and cross-sectional area in m². All values must be positive numbers greater than zero.
Q1: What Is Resistivity And How Does It Affect Resistance?
A: Resistivity is an intrinsic property of materials that quantifies how strongly they resist electric current. Materials with lower resistivity (like copper, silver) make better conductors.
Q2: Why Does Wire Length Affect Resistance?
A: Longer wires mean electrons must travel farther, encountering more collisions with atoms, thus increasing resistance proportionally to length.
Q3: How Does Cross-sectional Area Influence Resistance?
A: Larger cross-sectional area provides more pathways for electron flow, reducing resistance inversely with area.
Q4: What Are Common Resistivity Values For Different Materials?
A: Copper: 1.68×10⁻⁸ Ω·m, Aluminum: 2.82×10⁻⁸ Ω·m, Silver: 1.59×10⁻⁸ Ω·m, Gold: 2.44×10⁻⁸ Ω·m.
Q5: How Does Temperature Affect Wire Resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.