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!

Amount of energy stored in a magnetic field

  1. Apr 6, 2009 #1
    1. 1. An air-core solenoid with 57 turns is 4.96 cm
    long and has a diameter of 1.46 cm.
    The permitivity of free space is 4×10−7 T·
    m/A.
    How much energy is stored in its magnetic
    field when it carries a current of 0.634 A ?
    Answer in units of μJ.
    2.
    B = mu-o (I) (N)/ L
    Induction= mu-0 (N^2/l) A
    U= (1/2) Induction (I ^2)

    3. First I calculated Induction= 4pie-7 ( 57turns ^2/ .0496m) (pi(.0146^2))= 1.3785e-5

    Then I used U = (1/2) induction (0.634 A ^2)= 2.7355μJ

    I am on the wrong path? I thought of calculating the magentic field as well
    using my first eqaution= 9.09795 e-4 T but I couldn't find the correct eqaution/ relationship to calculate the energy stored. Thanks in advance for any help!
     
  2. jcsd
  3. Apr 6, 2009 #2

    rl.bhat

    User Avatar
    Homework Helper

    0.0146 is the diameter, not the radius.
     
  4. Apr 6, 2009 #3
    My mistake, I did use the diameter/ 2 in my calculations ( jsut translated it incorrectly) so I still had the same calculation. Is there something else I am missing?
     
  5. Apr 6, 2009 #4

    rl.bhat

    User Avatar
    Homework Helper

    Check the calculation of inductance.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Amount of energy stored in a magnetic field
  1. Stored Magnetic Energy (Replies: 2)

Loading...