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Resistivity Formula:
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Resistivity (ρ) is an intrinsic property of materials that quantifies how strongly they oppose electric current. It is measured in ohm-meters (Ω·m) and depends on the material's composition and temperature, but not on its dimensions.
The calculator uses the resistivity formula:
Where:
Explanation: The formula shows that resistivity is directly proportional to resistance and cross-sectional area, and inversely proportional to length.
Details: Resistivity calculation is essential for material selection in electrical engineering, designing conductors and insulators, quality control in manufacturing, 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 numbers greater than zero.
Q1: What Is The Difference Between Resistance And Resistivity?
A: Resistance depends on both the material and its dimensions, while resistivity is an intrinsic property of the material itself, independent of size or shape.
Q2: What Are Typical Resistivity Values For Common Materials?
A: Copper: ~1.68×10⁻⁸ Ω·m, Aluminum: ~2.82×10⁻⁸ Ω·m, Glass: ~10¹⁰ to 10¹⁴ Ω·m, Rubber: ~10¹³ to 10¹⁶ Ω·m.
Q3: How Does Temperature Affect Resistivity?
A: For most metals, resistivity increases with temperature. For semiconductors, resistivity decreases with temperature. Some materials like superconductors have zero resistivity below critical temperatures.
Q4: What Units Should I Use For The Calculation?
A: Use ohms (Ω) for resistance, square meters (m²) for area, and meters (m) for length to get resistivity in ohm-meters (Ω·m).
Q5: Can This Formula Be Used For All Materials?
A: This formula works for homogeneous, isotropic materials with uniform cross-section. For anisotropic materials or complex geometries, more advanced calculations are needed.