Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Shouldn't Emf generated be Derivative of Flux?

  1. Sep 20, 2015 #1
    Hey, I don't understand why emf generated is not the first derivative. For example I have a graph of magnetic flux through a wire against time. I thought that emf generated was the rate of change of flux, however this doesn't work. Emf=-Dflux/Dtime . In this example I have a y=sinx curve for the magnetic flux through wire and the answer is y=-cosx, which is the integral. Thanks in advance

    Attached Files:

  2. jcsd
  3. Sep 20, 2015 #2
    It's not the integral, its the negative (!) derivative with respect to time. You even posted the correct formula already. $$E = - \frac{d\,\Phi}{d\,t}$$ You need the minus sign due to Lenz's law.
  4. Sep 20, 2015 #3
    That was actually quite simple, thanks for your explanation
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook