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Resistivity Formula:
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Electrical resistivity (ρ) is a fundamental property that quantifies how strongly a material opposes the flow of electric current. It is the reciprocal of electrical conductivity (σ) and is measured in ohm-meters (Ω·m).
The calculator uses the resistivity formula:
Where:
Explanation: This inverse relationship means that materials with high conductivity have low resistivity, and vice versa. The formula converts between these two fundamental electrical properties.
Details: Resistivity calculation is crucial for material selection in electrical engineering, determining insulation properties, designing electronic components, and understanding material behavior in various applications.
Tips: Enter electrical conductivity in siemens per meter (S/m). The value must be greater than zero. The calculator will automatically compute the corresponding resistivity in ohm-meters (Ω·m).
Q1: What is the difference between resistivity and resistance?
A: Resistivity (ρ) is an intrinsic material property, while resistance (R) depends on both the material and its dimensions (R = ρL/A).
Q2: What are typical resistivity values for common materials?
A: Conductors (copper): ~1.68×10⁻⁸ Ω·m, Semiconductors (silicon): ~0.1-1000 Ω·m, Insulators (glass): ~10¹⁰-10¹⁴ Ω·m.
Q3: Why is resistivity temperature dependent?
A: Resistivity generally increases with temperature for conductors due to increased atomic vibrations, while it decreases for semiconductors.
Q4: How is resistivity measured experimentally?
A: Typically using a four-point probe method to eliminate contact resistance errors, especially for semiconductor materials.
Q5: What factors affect material resistivity?
A: Temperature, material purity, crystal structure, mechanical stress, and in semiconductors, doping concentration.