- #1
Wannabeagenius
- 91
- 0
Hi Guys,
This is going to be a bit controversial but that's ok.
In an RL circuit, both with and without a battery, Kirchoff's law is invoked in virtually every elementary textbook in the United States and perhaps in the world. It is a mistake!
The voltage drop across an inductor is zero. Of course I'm talking about a perfect inductor but I am also talking about an ideal circuit. The usage of Kirchoff's law works because fudging is done to get the correct answer.
The correct law to use is Faraday's law, the closed intergral of Edotdl equals the time rate of change of the magnetic flux. This, when used, does not require any fudging.
I'm hoping that I don't have to justify this but this is from MIT and I can justify it, if necessary.
But that still leaves me with a question. I know that the voltage drop across an inductor is zero, but what does "the induced emf equals minus Ldi/dt" mean physically?
Thank you,
Bob Guercio
This is going to be a bit controversial but that's ok.
In an RL circuit, both with and without a battery, Kirchoff's law is invoked in virtually every elementary textbook in the United States and perhaps in the world. It is a mistake!
The voltage drop across an inductor is zero. Of course I'm talking about a perfect inductor but I am also talking about an ideal circuit. The usage of Kirchoff's law works because fudging is done to get the correct answer.
The correct law to use is Faraday's law, the closed intergral of Edotdl equals the time rate of change of the magnetic flux. This, when used, does not require any fudging.
I'm hoping that I don't have to justify this but this is from MIT and I can justify it, if necessary.
But that still leaves me with a question. I know that the voltage drop across an inductor is zero, but what does "the induced emf equals minus Ldi/dt" mean physically?
Thank you,
Bob Guercio