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 fundamental formula R = ρL/A.

2. How Does the Resistance Calculator Work?

The calculator uses the resistance formula:

Where:

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

Explanation: The resistance increases with length and resistivity, but decreases with increasing cross-sectional area.

3. Importance of Resistance Calculation

Details: Accurate resistance calculation is crucial for electrical circuit design, wire sizing, power distribution systems, and ensuring proper operation of electrical devices and equipment.

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 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 Ω·m, Aluminum: 2.82×10⁻⁸ Ω·m, Silver: 1.59×10⁻⁸ Ω·m, Glass: 10¹⁰-10¹⁴ Ω·m.

Q3: How does temperature affect resistance?
A: For most conductors, resistance increases with temperature. The relationship is given by R = R₀[1 + α(T - T₀)], where α is the temperature coefficient.

Q4: What is the difference between resistance and resistivity?
A: Resistance depends on both the material and its dimensions, while resistivity is an intrinsic property of the material itself.

Q5: Why is cross-sectional area important?
A: Larger cross-sectional area provides more paths for electrons to flow, reducing resistance. This is why thicker wires have lower resistance.