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Re: Lenz 's Law



So, in contrast, consider what happens if you've
got a paramagnetic material. The induced Amperian
currents go in the _same_ direction as the
inducing current ... just the opposite of
what Lenz's law would tell you. - J Denker

This can be confusing if not clarified.

I would say this is confounding two phenomena which should be kept
conceptually distinct:
1) The torque on a magnetic dipole (ex a circular current loop) due to an
externally sourced B field will tend to line up the dipole with the
instantaneous direction of that B field so that the dipole's B field
strengthens the original, external B field (inside the loop). This can be
seen as just the result of the qVxB force.

2) A time varying B field generates an E field (Curl E = - dB/dt) which will
drive currents in accordance with Lenz's Law.

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor