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 that quantifies how strongly a given material opposes the flow of electric current.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: This formula calculates the resistivity of a material based on measured line losses, wire area, current, and wire length in a 2-phase 4-wire underground AC system.

3. Importance of Resistivity Calculation

Details: Accurate resistivity calculation is crucial for designing efficient electrical systems, selecting appropriate materials for wiring, and minimizing energy losses in power transmission.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What factors affect resistivity?
A: Resistivity depends on the material type, temperature, and in some cases, pressure and magnetic fields.

Q2: How does temperature affect resistivity?
A: For most conductors, resistivity increases with temperature, while for semiconductors, it typically decreases.

Q3: What are typical resistivity values for common materials?
A: Copper: ~1.68×10⁻⁸ Ω·m, Aluminum: ~2.82×10⁻⁸ Ω·m, Silver: ~1.59×10⁻⁸ Ω·m (at 20°C).

Q4: Why is resistivity important in power transmission?
A: Lower resistivity materials reduce energy losses during transmission, making the system more efficient.

Q5: Can this calculator be used for DC systems?
A: While the basic principles are similar, this specific formula is designed for 2-phase 4-wire AC underground systems.