Explanation:
- Diameter (D): Width of the coil from one side to the other.
- Turns (N): Number of times the wire is wrapped.
- Length (L): Distance from start to end of coil.
Inductance is calculated using Wheeler’s formula for an air-core solenoid:
L(μH) = (D² × N²) / (18D + 40L) (D and L in inches)