18. The current I, walking through the inductor L = 20 mH, varies with time t according to the law I = Imsinωt. The maximum value of the current Im = 8 A, its period T = 25 ms. Find function of time and the self-induction electromotive force ε energy W of the magnetic field coil.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)