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!

Induced Emf in a Rectangular Coil

  1. Mar 15, 2012 #1
    1. The problem statement, all variables and given/known data
    A rectangular coil of 90 turns has dimensions of 22 x 65 cm and is located in a uniform 1 T magnetic field. In 1.7 s, the plane of the coil is rotated from a position where it makes an angle of 19° with the magnetic field to a position where it makes an angle of 64°. Calculate the average emf induced in the coil.


    2. Relevant equations

    emf= -N*(d[itex]\Phi[/itex]/dt)
    [itex]\Phi[/itex]=BAcos[itex]\vartheta[/itex]


    3. The attempt at a solution

    So I calculated the change in flux to be: (B*A*cos(90-64))-(B*A*cos(90-19)=B*A*(cos(26)-cos(71))

    I then calculated emf.
    emf= - ((90 turns)*(1 T)*(0.22m*0.65m)*(cos(26)-cos(71)))/1.7 s = -4.34 V
    This is wrong. I then entered the absolute value, which is also incorrect.
     
  2. jcsd
  3. Mar 16, 2012 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Hi SgtMousse! :smile:
    looks ok :confused:

    have you tried 4.3 V, since it should be two significant figures ?​
     
  4. Mar 16, 2012 #3
    Apparently my answer was correct, even though it was marked wrong. I just checked my online homework site, and they marked it correct. They must have had it wrong before. Thanks anyway!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Induced Emf in a Rectangular Coil
Loading...