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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 material. It is a fundamental property in physics and electrical engineering that determines how much current will flow for a given voltage.
The calculator uses the resistance formula:
Where:
Explanation: The resistance of a conductor is directly proportional to its length and resistivity, 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 proper functioning of electronic devices.
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. For semiconductors, resistance typically decreases with temperature.
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, Glass: 10¹⁰-10¹⁴ Ω·m.
Q4: Why is cross-sectional area important?
A: Larger cross-sectional area provides more paths for electrons to flow, reducing resistance. This is why thicker wires have lower resistance.
Q5: Can this formula be used for all materials?
A: This formula works well for uniform conductors with constant cross-section. For complex geometries or non-uniform materials, more advanced calculations are needed.