eletromechancs circuit with air gap

Discussion in 'Homework Help' started by frequency377, Dec 13, 2014.

  1. frequency377

    Thread Starter New Member

    Dec 13, 2014
    can someone help me find the current i in this question. Your help will be greatly appreciated.
    • pic.jpg
      File size:
      36.4 KB
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    Show us your attempts so far, so that we can see the steps taken.
  3. frequency377

    Thread Starter New Member

    Dec 13, 2014
    i will attach this picture to show you guys the attempt i have made. I am confused with two things regarding this problem. 1. how to get the area of the air gap with the info given, 2. how to obtain the phi value.
  4. MrAl

    Distinguished Member

    Jun 17, 2014

    Usually the air gap area is allowed to be taken as the area of the two core faces if they are equal, as long as you are not required to compensate for field fringing at the gap which usually you dont have too, but this depends on what course you are taking and what the instructor has already given you (if the instructor never told you how to compensate for fringing then you dont worry about that).
    So if the upper arm core area is 1 sq cm and the lower is 1 sq cm, then the air gap area is also 1 sq cm in most cases. The larger the air gap the more the fringing affects the effective area, but if you can ignore these secondary effects then just use the core area.