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Resistance Formula:
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The resistance formula using resistivity calculates the electrical resistance of a material based on its intrinsic properties and physical dimensions. This fundamental relationship helps determine how much a material opposes electric current flow.
The calculator uses the resistance formula:
Where:
Explanation: The formula shows that resistance is directly proportional to both resistivity and length, and inversely proportional to cross-sectional area.
Details: Accurate resistance calculation is crucial for designing electrical circuits, selecting appropriate wire gauges, calculating power losses, and ensuring proper functioning of electronic devices and power systems.
Tips: Enter resistivity in Ω·m, length in meters, and cross-sectional area in m². All values must be positive numbers. Common resistivity values: copper = 1.68×10⁻⁸ Ω·m, aluminum = 2.82×10⁻⁸ Ω·m.
Q1: What Is Resistivity?
A: Resistivity is an intrinsic property of materials that quantifies how strongly they oppose electric current flow, independent of the material's shape or size.
Q2: How Does Wire Thickness Affect Resistance?
A: Thicker wires (larger cross-sectional area) have lower resistance, allowing more current to flow with less energy loss as heat.
Q3: Why Does Resistance Increase With Length?
A: Longer conductors provide more material for electrons to travel through, increasing collisions with atoms and thus increasing resistance.
Q4: What Are Typical Resistivity Values?
A: Conductors have low resistivity (10⁻⁸ Ω·m), semiconductors have moderate resistivity, and insulators have very high resistivity (10⁸-10¹⁶ Ω·m).
Q5: How Does Temperature Affect Resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.