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Electrical Conductivity and Resistance Formulas:
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Conductivity (σ) and resistivity (ρ) are inversely related fundamental electrical properties of materials. Resistance (R) depends on resistivity and the material's geometry according to the formula R = ρL/A.
The calculator uses these fundamental electrical formulas:
Where:
Explanation: Conductivity measures how well a material conducts electric current, while resistivity measures how strongly a material opposes current flow. Resistance depends on both the material's intrinsic resistivity and its physical dimensions.
Details: Understanding these relationships is crucial for designing electrical circuits, selecting appropriate materials for wiring, calculating power losses, and optimizing electrical systems for efficiency and safety.
Tips: Enter resistivity in Ω·m, length in meters, and cross-sectional area in m². All values must be positive numbers. The calculator will compute both conductivity and resistance.
Q1: What is the difference between resistance and resistivity?
A: Resistivity is an intrinsic property of the material, while resistance depends on both the material and its geometry (length and cross-sectional area).
Q2: Why are conductivity and resistivity inversely related?
A: Conductivity measures how easily current flows, while resistivity measures how difficult it is for current to flow - they are complementary properties.
Q3: 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, Glass: 10¹⁰-10¹⁴ Ω·m.
Q4: How does temperature affect resistivity?
A: For most metals, resistivity increases with temperature. For semiconductors, resistivity decreases with temperature.
Q5: What is the unit of conductivity?
A: Siemens per meter (S/m), which is equivalent to 1/(Ω·m).