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!

Magnetic Field - Torque on a Current Loop

  1. Apr 1, 2009 #1
    1. The problem statement, all variables and given/known data

    A circular coil of 720 turns and area 0.6 m^2 is in a uniform magnetic field of 0.63 T. The maximum torque exerted on the coil by the field is 0.0026 N · m.

    a) Calculate the current in the coil.

    b) Assume the 720 turns of wire are used to form a single-turn coil with the same shape but much larger area. What is the current if the maximum torque exerted on the coil by the field is 0.0026 N · m?

    NOTE: Sigfigs do not matter

    2. Relevant equations

    T = IABn

    3. The attempt at a solution

    Part A:
    I solved by substitution using the equation T = IABn, getting T = 9.5532e-6 N · m (answer is correct)

    Part B:
    This is the part I'm having trouble with. I thought I could fine the new Area doing the following (I'm sure this approach is wrong):

    .6 = pi*r^2, r*720 = 314.7
    A = pi*314.7^2, plugging in the new area into T = IAB gives the wrong answer.

    I'd be very grateful for any help.
     
  2. jcsd
  3. Apr 1, 2009 #2

    rl.bhat

    User Avatar
    Homework Helper

    I got 1.32644e-8 N-m
     
  4. Apr 2, 2009 #3
    yeah, Thanks. I got the same answer or thereabouts.

    After some algebra (and some help) I found that the new area A2 = (n^2)*A1.

    Plugging that into T = IAB gives the correct answer.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Magnetic Field - Torque on a Current Loop
Loading...