$\Psi (t)={\displaystyle \underset{t_0}{\overset{t}{\int }}{u}_{\mathrm{AB}}(\tau )\text{d}\tau }$

where t₀ is any instant before the first supply of electric energy

Note 1 to entry: The concept is only useful in the case of an inductive element.

Note 2 to entry: The definition of linked flux in circuit theory is consistent with the more general definition 121-11-24 given in electromagnetism. The linked flux in circuit theory is described by inverting the procedure for calculating induced voltage (121-11-28).