1. What is Electrical Resistance?

Electrical resistance is a measure of the opposition to the flow of electric current in a conductor. It depends on the material's properties, length, and cross-sectional area of the wire.

2. How Does the Calculator Work?

The calculator uses the resistance formula:

Where:

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

Explanation: Resistance increases with length and decreases with cross-sectional area. Different materials have different resistivity values.

3. Importance of Resistance Calculation

Details: Accurate resistance calculation is crucial for electrical circuit design, power transmission efficiency, and preventing overheating in electrical systems.

4. Using the Calculator

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.

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 object's shape or size.

Q2: How does wire thickness affect resistance?
A: Thicker wires (larger cross-sectional area) have lower resistance, allowing more current to flow with less energy loss.

Q3: Why does resistance increase with length?
A: Longer wires provide more opposition to electron flow as electrons collide with more atoms along the path.

Q4: What are typical resistivity values?
A: Conductors: Copper (1.68×10⁻⁸), Aluminum (2.82×10⁻⁸); Insulators: Glass (10¹⁰-10¹⁴), Rubber (10¹³-10¹⁶) Ω·m.

Q5: How does temperature affect resistance?
A: For most conductors, resistance increases with temperature due to increased atomic vibrations that impede electron flow.