1. What is Resistivity?

Resistivity (ρ) is a fundamental property of materials that quantifies how strongly they resist electric current. It's measured in ohm-meters (Ω·m) and depends on the material's nature rather than its shape or size.

2. How Does the Calculator Work?

The calculator uses the resistivity formula:

Where:

• \( \rho \) — Resistivity (Ω·m)
• \( R \) — Electrical resistance (Ω)
• \( A \) — Cross-sectional area (m²)
• \( L \) — Length of material (m)

Explanation: The equation shows that resistivity is directly proportional to resistance and cross-sectional area, and inversely proportional to length.

3. Importance of Resistivity Calculation

Details: Resistivity is crucial for selecting materials in electrical engineering, designing circuits, and understanding material properties for various applications.

4. Using the Calculator

Tips: Enter resistance in ohms, cross-sectional area in square meters, and length in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between resistance and resistivity?
A: Resistance depends on the material's dimensions, while resistivity is an intrinsic property independent of size or shape.

Q2: What are typical resistivity values?
A: Conductors (e.g., copper) have low resistivity (~10⁻⁸ Ω·m), insulators (e.g., glass) have high resistivity (~10¹² Ω·m), and semiconductors fall in between.

Q3: How does temperature affect resistivity?
A: For most metals, resistivity increases with temperature. For semiconductors, it typically decreases with temperature.

Q4: What are common units for resistivity?
A: The SI unit is Ω·m, but Ω·cm (1 Ω·m = 100 Ω·cm) is also commonly used.

Q5: How is resistivity measured experimentally?
A: Typically by measuring resistance of a sample with known dimensions using a four-point probe method for accuracy.