18_3?Induction:?Eddy?Currents Apr/8/2016 M.?Burkardt?? NMSU?? PHYS?214?? Spring?2016 1 Phys214 Electricity & Magnetism Induced Electric Fields, Eddie Currents, Generator Changing Magnetic Fields are Accompanied by Electric Fields Faraday?s law: As magnetic flux changes, an induced current flows. What causes the charges to move? Magnetic fields cannot do work, so the work done must be due to an electric field! This electric field cannot be conservative, because for a conservative field b aV d? ? ? E ?? ? ? 0d ?? E ?? ? ?? loop B d dt? ?? ? Induced Electric Fields magnetic flux through the loop: 0B NBA AIL? ? ?? ? ? ? ?? ? induced emf: 0Bind d N dIAdt L dt? ? ?? ? ? ? The changing magnetic flux induced an electric field in the conducting loop.