Solenoid Coil Inductance & Stored Magnetic Energy Calculator
Calculate solenoid coil inductance (Henrys, mH, μH), stored magnetic energy (Joules/mJ), magnetic flux density (B Tesla), and ferrite core permeability.
Calculated Results
Frequently Asked Questions
What is the formula for solenoid coil inductance?
Formula: L = (mu_0 × mu_r × N^2 × A) / l, where mu_0 is the permeability of free space (4π × 10^-7 H/m), mu_r is relative core permeability, N is turn count, A is cross-sectional area (π r^2), and l is coil length.
Why does inductance scale with the square of the turns (N²)?
Doubling the number of turns doubles the magnetic field strength B inside the coil and simultaneously doubles the total magnetic flux linkages, multiplying total inductance by a factor of 4 (N^2).
How does an iron or ferrite core amplify inductance?
Ferromagnetic materials have high relative permeability (μr from 100 to over 2,000). Inserting a ferrite core concentrates magnetic flux lines, increasing coil inductance thousands of times without adding extra copper wire.
What is the magnetic energy stored in an inductor?
Energy formula: E = 0.5 × L × I^2 (in Joules). Unlike capacitors which store potential energy in an electric field between plates, inductors store kinetic energy dynamically in their surrounding magnetic field.