Since the field in the title is opposing the original magnetic flux that causes the induction, how can it be reduced? I understand that a laminated magnetic core can be used. 1) Where is this magnetic laminated core placed? 2) Can it be obtained from specialized manufacturers? 3) My choice for the permanent magnet is the natural kind. Would this be the best choice, given that artificially magnetized materials lose their strength in time? Sorry for the awkward, all-over-the-place manner in which I post the questions. I am ignorant and eager. I appreciate, beforehand, the knowledge and patience of all respondents.