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!

Lenz's Law problem

  1. Mar 27, 2007 #1
    I'm reviewing for a midterm and I'm stuggling with this question because I'm not sure what equation would be appropirate. I believe that it is Lenz's Law, but I need some suggestions as to what equation to use.

    Question:
    To monitor the breathing of a hospital patient, a thin belt is girded around the patient's chest. The belt is a 213 turn coil. When the patient inhales, the area encircled by the coil increases by 39.0 cm2. The magnitude of the Earth's magnetic field is 50.0 µT and makes an angle of 28.0° with the plane of the coil. Assuming that a patient takes 1.80 s to inhale, find the average induced emf in the coil during this time.

    any help would be appreciated!
     
  2. jcsd
  3. Mar 27, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Look up Faraday's law. That's the one you need.
     
  4. Mar 27, 2007 #3

    GmL

    User Avatar

    Yeah, Doc Al is correct.

    You know that emf= - (d/dt) (magnetic flux)

    and since n=213, B=50x10^-6, and theta=62 degrees (remember, you're finding the angle between the area vector A, which is perpendicular to the loop, and B), we can solve.

    the n, cos(theta), and B all come out of the derivative, leaving dA/dt, which is trivial to solve. And thus, you have the answer.:smile:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Lenz's Law problem
  1. Lenz's law, induction (Replies: 4)

Loading...