1. What is Resistivity?

Resistivity is the measure of how strongly a material opposes the flow of current through them. It is a fundamental property of materials that determines how well they conduct electricity.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \rho \) — Resistivity (Ω·m)
• \( A \) — Area of Underground AC Wire (m²)
• \( P_{loss} \) — Line Losses (W)
• \( I \) — Current Underground AC (A)
• \( L \) — Length of Underground AC Wire (m)

Explanation: This formula calculates the resistivity of the wire material based on the measured line losses, current, and physical dimensions of the wire.

3. Importance of Resistivity Calculation

Details: Calculating resistivity is crucial for selecting appropriate materials for electrical wiring, designing efficient power transmission systems, and understanding the electrical properties of different materials.

4. Using the Calculator

Tips: Enter the area of the wire in square meters, line losses in watts, current in amperes, and length of the wire in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical resistivity range for common conductors?
A: Copper has resistivity of about 1.68×10⁻⁸ Ω·m, while aluminum is about 2.82×10⁻⁸ Ω·m at 20°C.

Q2: How does temperature affect resistivity?
A: For most metals, resistivity increases with temperature due to increased atomic vibrations that impede electron flow.

Q3: Why is the factor of 2 in the denominator?
A: The factor of 2 accounts for the return path in single-phase systems, making the total conductor length twice the physical length.

Q4: What are common units for resistivity?
A: The SI unit is ohm-meter (Ω·m), but ohm-centimeter (Ω·cm) and ohm-inch (Ω·in) are also used.

Q5: How accurate is this calculation method?
A: This method provides a good estimate but assumes uniform material properties and may not account for temperature variations or material impurities.