Self InductionSelf induction is a phenomenon by which a changing electric current produces an induced emf across the coil itself.Self InductanceSelf inductance is the ratio of induced electromotive force (EMF) across a coil to the rate of change of current through the coil. We denote self inductance or coefficient of with English letter L. Its unit is Henry (H).Since, the induced emf (E) is proportional to the current changing rate, we can write,But the actual equation isWhy there is Minus (-) s