1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Faraday's Law of Induction and wire loop

  1. Apr 1, 2007 #1
    1. The problem statement, all variables and given/known data
    A wire loop of radius 0.3m lies so that an external magnetic field of magnitude 0.30 T is perpendicular to the loop. The field reverses its direction, and its magnitude changes to 0.20 T in 1.5s. Find the magnitude of the average induced emf in the loop during this time.

    2. Relevant equations
    [tex] \varepsilon_{avg} = \frac{-\Delta \Phi_{B}}{\Delta t}[/tex]

    [tex]\Phi_{B}=BAcos \theta [/tex]

    3. The attempt at a solution
    [tex]A=\pi r^{2}=\pi (0.30m)^{2}= 0.09\pim^{2}[/tex]

    [tex]0s: \Phi_{B}=BA cos \theta =(0.30T)(0.09\pi m^{2}) = 0.0848 T*m^{2}[/tex]

    [tex]1.5s: \Phi = -(0.20T)(0.09\pi m^{2})= -0.05655 T*m^{2}[/tex]


    The correct answer, however, is 94 mV??
    Last edited: Apr 1, 2007
  2. jcsd
  3. Apr 1, 2007 #2
    Nvm, I found my mistakes. Just some arithmetic errors :grumpy:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook