1. What is Electrical Resistance?

Electrical resistance is a measure of the opposition to current flow in an electrical circuit. It depends on the material's resistivity (ρ), the length of the conductor (L), and its cross-sectional area (A).

2. How Does the Resistance Calculator Work?

The calculator uses the resistance formula:

Where:

• \( R \) — Resistance in ohms (Ω)
• \( \rho \) — Resistivity of the material (ohm·m)
• \( L \) — Length of the conductor (meters)
• \( A \) — Cross-sectional area of the conductor (m²)

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

3. Importance of Resistance Calculation

Details: Accurate resistance calculation is crucial for designing electrical circuits, selecting appropriate wire gauges, and ensuring proper current flow in electronic devices.

4. Using the Calculator

Tips: Enter resistivity in ohm·m, length in meters, and cross-sectional area in m². All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical resistivity values?
A: Copper: ~1.68×10⁻⁸ Ω·m, Aluminum: ~2.65×10⁻⁸ Ω·m, Silver: ~1.59×10⁻⁸ Ω·m (at 20°C).

Q2: How does temperature affect resistance?
A: For most metals, resistance increases with temperature due to increased atomic vibrations.

Q3: What's the difference between resistance and resistivity?
A: Resistivity is an intrinsic property of the material, while resistance depends on both the material and its dimensions.

Q4: Why does resistance decrease with larger cross-sectional area?
A: A larger area provides more pathways for electrons to flow, reducing opposition to current.

Q5: Can this formula be used for all materials?
A: It works well for uniform conductors at constant temperature but may not apply to semiconductors or non-ohmic materials.