1. What is Electrical Resistance?

Electrical resistance is a measure of the opposition to the flow of electric current in a material. It depends on the material's resistivity, length, and cross-sectional area according to the formula R = ρL/A.

2. How Does the Calculator Work?

The calculator uses the resistance formula:

Where:

• \( R \) — Electrical resistance (ohms)
• \( \rho \) — Resistivity of the material (ohm-m)
• \( L \) — Length of the conductor (m)
• \( A \) — Cross-sectional area of the conductor (m²)

Explanation: Resistance increases with longer conductors and higher resistivity materials, but decreases with larger cross-sectional areas.

3. Importance of Resistance Calculation

Details: Calculating resistance is essential for designing electrical circuits, selecting appropriate wire sizes, preventing overheating, and ensuring proper voltage drops in electrical systems.

4. Using the Calculator

Tips: Enter resistivity in ohm-meters, length in meters, and cross-sectional area in square meters. All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

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: What are typical resistivity values?
A: Copper: ~1.68×10⁻⁸ ohm-m, Aluminum: ~2.82×10⁻⁸ ohm-m, Silver: ~1.59×10⁻⁸ ohm-m, Iron: ~1.0×10⁻⁷ ohm-m.

Q3: How does temperature affect resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.

Q4: What is the difference between resistance and resistivity?
A: Resistivity is a material property, while resistance depends on both the material and its physical dimensions (length and cross-sectional area).

Q5: When is this formula not applicable?
A: This formula assumes uniform material properties, constant temperature, and DC conditions. It may not be accurate for high-frequency AC applications or non-uniform materials.