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Resistivity Formula:
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The resistance to resistivity formula calculates the resistivity (ρ) of a material based on its electrical resistance (R), cross-sectional area (A), and length (L). Resistivity is an intrinsic property that characterizes how strongly a material opposes electric current flow.
The calculator uses the resistivity formula:
Where:
Explanation: This formula relates the measurable resistance of a material sample to its intrinsic resistivity, accounting for the sample's dimensions.
Details: Resistivity is crucial for material selection in electrical engineering, determining conductor efficiency, designing electronic components, and understanding material properties for various applications.
Tips: Enter resistance in ohms (Ω), cross-sectional area in square meters (m²), and length in meters (m). All values must be positive and non-zero for accurate calculation.
Q1: What is the difference between resistance and resistivity?
A: Resistance depends on the material's dimensions, while resistivity is an intrinsic property that depends only on the material itself and temperature.
Q2: 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.
Q3: How does temperature affect resistivity?
A: For most metals, resistivity increases with temperature. For semiconductors, resistivity decreases with temperature.
Q4: What are the units of resistivity?
A: The SI unit is ohm-meter (Ω·m), but ohm-centimeter (Ω·cm) is also commonly used (1 Ω·m = 100 Ω·cm).
Q5: When is this formula most accurate?
A: This formula is most accurate for uniform materials with constant cross-section and when measurements are taken at constant temperature.