Home
Back
Resistivity Formula:
| From: | To: |
The resistivity formula calculates the electrical resistance of a wire based on its material properties and physical dimensions. It describes how much a material opposes the flow of electric current.
The calculator uses the resistivity formula:
Where:
Explanation: The formula shows that resistance increases with length and decreases with cross-sectional area, while being proportional to the material's inherent resistivity.
Details: Accurate resistance calculation is crucial for electrical circuit design, wire sizing, power transmission efficiency, and preventing overheating in electrical 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 resist electric current, independent of the object's shape or size.
Q2: How does wire diameter affect resistance?
A: Resistance decreases with increasing diameter because cross-sectional area increases, providing more pathways for electrons to flow.
Q3: What are typical resistivity values?
A: Conductors have low resistivity (10⁻⁸ Ω·m), semiconductors moderate (10⁻⁵ to 10⁶ Ω·m), and insulators high resistivity (>10⁸ Ω·m).
Q4: Does temperature affect resistivity?
A: Yes, for most metals, resistivity increases with temperature due to increased atomic vibrations that scatter electrons.
Q5: How is this formula used in real applications?
A: Used in electrical engineering for wire sizing, circuit design, power transmission planning, and electronic component manufacturing.