Faraday's law and perpetual motion

[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?

 

[marcusl]

Is this a homework question?

 

[Princess19]

no, its a test question and i want to see if i got it right :)

 

[zorro]

perpetual motion of?

 

[Princess19]

I think the answer is true, since the sign is positive, it doesn't oppose the change in magnetic flux, therefore violating the law of conservation of energy, and itll never stop moving as it increases in velocity.

 

[marcusl]

Agreed. Consider a wire ring in a changing magnetic field. The induced emf would generate a current whose magnetic field reinforced (instead of opposed) the external field, creating positive feedback. I wouldn't call that perpetual motion exactly, but in spirit "True" is the right answer.