Mutual Inductance
The induction of an electromotive force in a secondary circuit loop caused by a time-varying current in an adjacent primary circuit loop.
Governing formula
E₂ = -M (dI₁/dt), M = k √(L₁ L₂)
SI unit
H (Henries)
In depth
The coupling coefficient k (0 ≤ k ≤ 1) measures how efficiently magnetic flux generated by the primary coil links into the secondary coil structure.
Examples in the real world
Wireless smartphone inductive charging pads transferring electrical power across air gaps to phone receiver coils.