Editing Magnetic core (section)

===Eddy-current losses===
If the core is electrically [[electrical conductivity|conductive]], the changing magnetic field induces circulating loops of current in it, called [[eddy current]]s, due to [[electromagnetic induction]].<ref>{{cite book|last1=Kazimierczuk|first1=Marian K.|title=High-frequency magnetic components|date=2014|publisher=Wiley|location=Chichester|isbn=978-1-118-71779-0|page=113|edition=Second}}</ref>  The loops flow perpendicular to the magnetic field axis.  The energy of the currents is dissipated as heat in the resistance of the core material.  The power loss is proportional to the area of the loops and inversely proportional to the resistivity of the core material. Eddy current losses can be reduced by making the core out of thin [[lamination]]s which have an insulating coating, or alternatively, making the core of a magnetic material with high electrical resistance, like [[ferrite (magnetic core)|ferrite]].<ref>{{cite book|last1=Erickson|first1=Robert|last2=Maksimović|first2=Dragan|title=Fundamentals of Power Electronics, Second Edition|date=2001|publisher=Kluwer Academic Publishers|isbn=9780792372707|page=507}}</ref> Most magnetic cores intended for power converter application use ferrite cores for this reason.