The first law of commutation

The current in the branch with the inductive coil cannot change abruptly. At the first moment, the transient current retains the value that it had at the moment preceding the switching, i.e. i (0-) = i (0+).



I = 0 ÷ E / R
in t (0-) → I = 0
in t (∞) → I = E / R

This conclusion was made on the basis of the impossibility of an instantaneous change in electrical and magnetic energy.
Those. let the current in the inductance change abruptly, then:



and the stored energy must also change abruptly.

Because

But the power can not be infinitely large, so the current in the coil can not change abruptly in contrast to the voltage.