Question about faraday's law of induction?

Thread starter Princess19
Start date Dec 8, 2010
Tags

Faraday's law Induction Law

AI Thread Summary

If Faraday's law of induction included a positive sign instead of a negative one, it would imply the possibility of perpetual motion. This assertion raises questions about the nature of feedback in systems, suggesting that positive feedback could lead to unlimited growth. The discussion highlights the importance of understanding the implications of sign conventions in physical laws. Ultimately, the presence of a positive sign would contradict established principles of thermodynamics. The conversation emphasizes the need for careful consideration of the effects of feedback in scientific theories.

Dec 8, 2010

Princess19

If a positive sign were present in Faraday's law instead of a negative sign, this would lead to perpetual motion..

True or false?

Physics news on Phys.org

Dec 10, 2010

cragar

I want to say yes . But hopefully someone can verify.

Dec 10, 2010

Studiot

Good question.

And the answer may be a little different from what you expect.

Think about positive v negative feedback and growth without limit.

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...

View full post »

Thread 'Why measure the speed of light in one direction?'

It may be shown from the equations of electromagnetism, by James Clerk Maxwell in the 1860’s, that the speed of light in the vacuum of free space is related to electric permittivity (ϵ) and magnetic permeability (μ) by the equation: c=1/√( μ ϵ ) . This value is a constant for the vacuum of free space and is independent of the motion of the observer. It was this fact, in part, that led Albert Einstein to Special Relativity.

View full post »