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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?.
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