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Re: EMF



Chuck Britton wrote:

It's not 'easy' to apply K's Loop Rule to induced 'EMF's".

Or, in modern language, to induced voltages.

And not 'easy' is a humorous way of saying not _possible_.

Kirchhoff's node "rule" is tantamount to assuming that
all electric-field lines of interest are confined
inside capacitors and such (which may or may not be true).

Similarly, K's loop "rule" is tantamount to assuming
that all magnetic-field lines of interest are
confined inside inductors, transformers, and such
(which may or may not be true).

In particular, the existence of nontrivial induced
voltages around a loop is diametrically inconsistent
with K's loop "rule".

What are the appropriate adjectives to attach in the
case of K's Loop Rule?

The adjective that goes in front of "voltage" is "induced".
Throw in "non-potential" if you think it helps.

As for the adjective that goes in front of Loop Rule,
take your pick:
-- invalid
-- inapplicable
-- would-be
-- supposed
-- erstwhile
-- unphysical
-- fallacious
-- false
Also "pseudo-rule" conveys the right idea, but syntactically
it doesn't combine well with appositives such as "Loop", so you
have to say something like Kirchhoff's Pseudo-Rule for Loops.