Re: Error in Wikipedia article: Faraday's law of induction

On 12 Jul, 12:19, phil-news-nos...@[EMAIL PROTECTED]
 wrote:
> It seems there is an error in this Wikipedia article:
>
> =A0 =A0http://en.wikipedia.org/wiki/Faraday%27s_law_of_induction
>
> Faraday's law says the induced EMF is in pro****tion to the rate of
CHANGE
> (my emphasis) of the magnetic flux. =A0The article describes this much
OK=
..
> Later on, the article then says:
>
> =A0 =A0 In the case of motional EMF, the idea is to move all or part of
t=
he
> =A0 =A0 circuit through the magnetic field, for example, as in a
homopola=
r
> =A0 =A0 generator.
>
> But this last case is a situation where the magnetic flux does not
change=
..
> Isn't this the aspect that Faraday saw as a paradox because it did not
ob=
ey
> his law of induction? =A0Apparently he realized that no flux change
happe=
ned
> when he rotated the magnets with the rotating disk in his unipolar
genera=
tor.
>
> As I understand all this, there are TWO ways to induce electricity from
a
> magnetic field:
>
> 1. =A0A conductor at a right angle to the magnetic field alignment
experi=
encing
> =A0 =A0 a change in the magnetic field flux density (strength).
=A0[Farad=
ay's law
> =A0 =A0 of induction]
>
> 2. =A0Motion of a conductor at right angle to the magnetic field
alignmen=
t and
> =A0 =A0 simultaneously at right angle to the line of the conductor.
=A0[F=
leming's
> =A0 =A0 right hand rule, Lorentz force law]


> The article seems to be trying to convert everything into one.

Which is correct, as far as Faraday's Law is concerned. The induced
EMF around a closed circuit is equal to the rate of change of flux
through the circuit and independent of whether it's the conductor or
the magnetic filed which is "moving".


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