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!

Basic Math

  1. Oct 15, 2008 #1

    This is not homework, i'm just confused:

    I have been asking on the electrical engineering forum about calculating the strength of electromagnets.

    After some searching i have found the equations but i just can't quite get a handle on some of it?

    They have an iron core C shaped electromagnet 15cm long & 1cm square in area.

    They write: The reluctance of the air gap is 1 centimeter divided by 1 times 1 square centimeter.

    The answer they have is 100 henries per meter.

    How do they calculate this to get 100 as the answer?

  2. jcsd
  3. Oct 15, 2008 #2
    I forgot to add that the air gap is 1cm & the permeability of air is 1 in this example.

  4. Oct 15, 2008 #3
    Ok, i'll have a go at it, the equation is:

    (1 centimeter) / (1 * 1 (square centimeter)) = 100 m-1

    I noticed that Reluctance is in Henries per Meter but the above calculation is in Centimeters so i assume the answers i have been getting are actually Henries per Centimeter, do i simply multiply the answer by 100 to change it to meters & then the answer is in Henries per meter & seem correct?.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook