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Re: EM Induction - A conceptual question



A time varying magnetic field is a source of an E field in the same
(mathematical) way that an electrical current is a source of a magnetic
field. To see this, just compare the two Maxwell equations:

1) Curl(B) = mu*j shows the electrical current density [j] as a curl
source of B fields ;
2) Curl(E) = - dB/dt shows the time varying B field as a curl source of E
fields.
Note that both these sources produce fields at distant points, not merely
at their own location.

Application of Stokes theorem generates Ampere's law from 1) and Faraday's
law from 2)

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor
----- Original Message -----
From: "Fakhruddin, Hasanbhai" <hfakhrud@BSU.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Friday, April 12, 2002 12:02 PM
Subject: EM Induction - A conceptual question


. . .
By the Faraday's law there should be an emf induced becuse of changing
flux. However, my contention is that B-field lines are not "physically"
linked to the loop. Why should changing field affect anything in the
loop?

-Hasan Fakhruddin