1. Not finding help here? Sign up for a free 30min 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!

Find the induced magnetic current on the inner of two rings

  1. Apr 28, 2013 #1
    1. The problem statement, all variables and given/known data
    A small, 1.60-mm-diameter circular loop with R = 1.10×10−2Ω is at the center of a large 120-mm-diameter circular loop. Both loops lie in the same plane. The current in the outer loop changes from + 1A to -1A in 8.00×10^−2s .

    What is the induced current in the inner loop? in nA

    2. Relevant equations

    I=ε/R
    ε=Phi/t
    Phi=A*B
    3. The attempt at a solution

    I=ε/R

    Phi=(Area)*(Magnitude of field)
    Phi = (PI*(8x10^-4^2 m^2)*??)

    I am completely unsure of what to do after this. Please help! Thanks.
     
  2. jcsd
  3. Apr 28, 2013 #2
    Ok, I tried this:

    B=mu*I/2R

    B1=4PIx10^-7 * +1 / 2*(1.1x10^-2)= 0.000785 T

    B2=4PIx10^-7 * -1 / 2*(1.1x10^-2)= -0.000785 T

    I=V/R

    V=PHI1-PHI2/t

    PHI1=A*B1

    PHI1=PI*(8x10^-4)^2 * 0.000785 =1.58x10^-9

    PHI2=A*B2=PI*(8x10^-4)^2 * - 0.000785=-1.58x10^-9

    V=(1.58x10^-9)*2/(8x10^-2)
    V=3.95x10^-8

    I=V/R

    I=(3.95x10^-8)/(1.1x10^-2)
    I=3.59x10^-6 A =3590 nA

    Yes?


    I submitted, but this was not correct. The correct answer was 4.79 nA. Can anyone please explain how?
     
    Last edited: Apr 28, 2013
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Find the induced magnetic current on the inner of two rings
Loading...