1. What is Inductance of a Straight Wire?

Definition: This calculator computes the self-inductance of a straight, round wire in free space.

Purpose: It helps electrical engineers and physicists determine the inductance of conductors in circuit design and analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( L \) — Inductance (henrys)
• \( \mu_0 \) — Permeability of free space (4π×10⁻⁷ H/m)
• \( l \) — Length of the wire (meters)
• \( r \) — Radius of the wire (meters)

Explanation: The formula accounts for both the internal and external inductance of the straight conductor.

3. Importance of Wire Inductance Calculation

Details: Understanding wire inductance is crucial for high-frequency circuit design, transmission line analysis, and minimizing unwanted inductive effects.

4. Using the Calculator

Tips: Enter the wire length and radius in meters. Both values must be positive numbers. The radius should be much smaller than the length for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What is the permeability constant (μ₀)?
A: μ₀ is the magnetic constant (4π×10⁻⁷ H/m), representing the permeability of free space.

Q2: Does this formula work for any wire material?
A: Yes, but it assumes non-magnetic materials (relative permeability μᵣ ≈ 1). For magnetic materials, multiply the result by μᵣ.

Q3: How does wire length affect inductance?
A: Inductance increases with length but not linearly due to the logarithmic term in the formula.

Q4: Why is wire radius important?
A: Thicker wires have lower inductance because the magnetic field has more area to spread out.

Q5: When is this approximation valid?
A: This formula works best when length ≫ radius (typically l/r > 100). For short wires, more complex models are needed.