1. What is Inductance of an Inductor Coil?

Definition: Inductance is the property of an electrical conductor that opposes a change in current, measured in henrys (H).

Purpose: This calculator helps determine the inductance of a coil based on its physical characteristics, important for designing circuits, transformers, and electromagnetic devices.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The inductance increases with more turns, larger area, higher permeability, and decreases with longer coil length.

3. Importance of Inductance Calculation

Details: Proper inductance calculation is crucial for designing filters, oscillators, power supplies, and any circuit where energy storage in magnetic fields is important.

4. Using the Calculator

Tips:

• Permeability of free space: 1.256637×10⁻⁶ H/m
• For iron cores, permeability can be 50-5000 times higher
• Number of turns must be an integer ≥ 1
• All dimensional values must be > 0

5. Frequently Asked Questions (FAQ)

Q1: What's the permeability of common materials?
A: Air/vacuum: ~1.26×10⁻⁶ H/m, Iron: ~6.3×10⁻³ H/m, Ferrite: ~1.26×10⁻⁴ to 1.26×10⁻³ H/m.

Q2: How does coil shape affect inductance?
A: This formula assumes a solenoid. Other shapes require different formulas accounting for geometry.

Q3: Why is N squared in the formula?
A: Because both the magnetic field and flux linkage increase with turns, leading to a squared relationship.

Q4: What if my coil has multiple layers?
A: The formula still applies, but accuracy decreases with very short, fat coils or multiple layers.

Q5: How precise is this calculation?
A: It's a good approximation for long solenoids (length ≫ diameter). For precise designs, consider edge effects and exact core properties.