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Active8

Jan 1, 1970
0
No, the direction of the induced EMF is such as to oppose the change of
current that produced it, hence:

V = -L di/dt

As you say, di/dt is negative, hence the induced voltage is positive,

Hmmm. Difference between voltage drop and counter EMF. Let's see how
many screw ups I can find.

I see Haliday and Resnick managed to foul things up by first writing

lineIntegral [ E.dl ] = -d_phi/dt

and then in the chapter on Maxwell they drop the negative sign and
reference the above eq as if they didn't change it. That's Table
37-1 with no mention of why it's dropped. In Table 37-2 the put it
back and never mention why but they discuss adding a missing term to
Ampere's Law from a prior chapter.

No where else to look for screw ups. Oh well, at least I remember
which way the protection diode goes.
 
R

Rich Grise

Jan 1, 1970
0
Active8 wrote:

Our general terminology in E&M is very useful but not how things
"really" "are". Of course we all use concepts such as, changing magnetic
fields "causing" electric fields an other such heuristic descriptions,
but one should always keep in mind that it is just macro descriptions of
things we don't even know the "true" operation of.

When you learn to see the higher dimensionality of Reality, it becomes
crystal clear, and impossible to describe or explain. ;-)

Cheers!
Rich
 
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