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!

Homework Help: Inductance of a solenoid

  1. Apr 14, 2004 #1
    A solenoid has 140 turns uniformly wrapped around a soft iron core, which has a magnetic permeability =750 Uo (mue sub-knot) diameter of 10.0m and a length of 9.00cm.

    What is the inductance in milli-henry (mH)?

    Did I set this up right? Using L=(uN^2A)/length, you get:

    (750*140^2*pi.005m^2*.09m)/.09m = 1.15E3 Henry = 1.15E6 Milli-Henry

    I think I made a conversion error somewhere. If not, why would they ask for the inductance in milli-henry, and not kilo-henry? :confused:
     
  2. jcsd
  3. Apr 15, 2004 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Your formula for L is correct. In your arithmetic I see two errors: an extra 0.09m on top, and--most importantly--a missing μ0. The permeability is μ = 750 μ0; μ0 = 4π10-7 N/A2.
     
  4. Apr 20, 2004 #3
    ohhhhhhhhhhh! Thanks!
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...