1. What is Coil Inductance?

Inductance is the property of an electrical conductor which opposes the change of current flowing through it. In coils, this property is enhanced by multiple turns of wire.

2. How Does the Calculator Work?

The calculator uses the inductance formula:

Where:

• \( L \) — Inductance in microhenries (μH)
• \( N \) — Number of turns
• \( \mu \) — Permeability of the core material (H/m)
• \( A \) — Cross-sectional area of the coil (m²)
• \( l \) — Length of the coil (m)

Explanation: The inductance increases with the square of the number of turns and the core's permeability, and decreases with coil length.

3. Importance of Inductance Calculation

Details: Accurate inductance calculation is crucial for designing circuits, filters, transformers, and other electronic components where precise inductive reactance is needed.

4. Using the Calculator

Tips: Enter all values in the specified units. For air-core coils, use μ = 1.256637 × 10⁻⁶ H/m (permeability of free space).

5. Frequently Asked Questions (FAQ)

Q1: What affects a coil's inductance?
A: Inductance depends on number of turns, core material, coil geometry (length and diameter), and turn spacing.

Q2: What's the difference between μH and H?
A: 1 μH (microhenry) = 10⁻⁶ H (henry). Most small coils have inductance in the μH range.

Q3: How does core material affect inductance?
A: Ferromagnetic cores (like iron) increase permeability (μ) significantly, resulting in higher inductance compared to air cores.

Q4: Can I calculate inductance for non-cylindrical coils?
A: This formula is for solenoids. Other shapes (toroids, flat spirals) require different formulas.

Q5: Why does inductance increase with N²?
A: Each turn contributes to the magnetic field and also links with the flux from other turns, resulting in a squared relationship.