Faraday's Law and magnetic flux

AI Thread Summary
A changing magnetic flux induces an electromotive force (emf) due to the transformation of the magnetic field as described by the Lorentz equations. This phenomenon is rooted in Faraday's Law, which is an experimental law rather than a derivable theory, leading to ongoing inquiries about its fundamental basis. The discussion emphasizes that scientific understanding should not rely on faith but on the ability to verify predictions. Participants express that serious scientists question and think critically about theories rather than accepting them blindly. Ultimately, the inquisitive nature of science drives advancements beyond classical physics.
Gza
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Why is it that a changing magnetic flux through a surface should induce an emf? I know that the emf is from a non-conservative electric field, but how exactly was this field generated? (if that is the correct expression for it)
 
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When someone gives you an answer as to why this happens, won't you just want to know why whatever answer they gave happens? What will this explanation tell you, exactly?

In my humble opinion whether you accept a paradigm a famous scientist offers you shouldn't depend on whether there is a more fundamental explanation proposed later, but instead depend on wether you can verify it to be a good predictor - which with Faraday's Law is easy to do.
 
THe apearance of the emf is due to the transformation of the B field to the reference frame of the wire. The transformation laws are governed by the Lorenz equations. I guess this explanation ( given in more detail) is a more fundamental and satisfactory one. Dont forget Faraday was an experimental guy. It's an experimental law
 
Gza said:
I know that most people are all too willing to take whatever some famous scientist says on faith ...
I've never met a physicist who took anything on faith. To be honest, I don't recall anyone who seriously studies science taking anything on faith.
..and simply learn their theories without thinking what they mean, ..
I've also never met anyone who seriously studies science who didn't think when learning a theory.
Why is it that a changing magnetic flux through a surface should induce an emf?
You've never learned it because nobody knows the answer to that question. I.e. it's one of Maxwell's equations and those equations are postulates, i.e. not derivable from from other postulates.

For details please see - http://rustam.uwp.edu/202/lec18_19.html

Pete
 
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When someone gives you an answer as to why this happens, won't you just want to know why whatever answer they gave happens? What will this explanation tell you, exactly?


This is the nature of an inquisitive mind. If it weren't for people asking why, we would still be in the realm of classical physics, with no motivation to advance.

And I apologize if my original post seemed to be confrontational to anyone; the people on this board are obviously the last people one would expect to take things on faith. It just seemed like a sensible question to ask.
 
Gza said:
And I apologize if my original post seemed to be confrontational to anyone; the people on this board are obviously the last people one would expect to take things on faith. It just seemed like a sensible question to ask.

No problemo! I all the years I've been posting in physics boards on the internet I've seen many people think that physicists are just gulible people who believe anything a prof tells them too. I don't know why people make that assumption so much but it does seem to be a common theme to those people who are not scientists.

Pete
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
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