Measurement of coefficient of self-induction and mutual induction.

When a current increases, there develops an electromotive force of self-induction which tends to oppose the current; on the contrary, when the current decreases, the electromotive force of self-induction tends to maintain the current.

Now, it's known that electric currents show a special kind of inertia, which is denoted as self-induction.

We know that electric currents produce the phenomena of induction, in particular self-induction.

We can imagine quite easily the phenomenon of self-induction at the time of the power cut.