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Electricity 12th Grade

  1. Nov 17, 2008 #1
    1. The problem statement, all variables and given/known data

    The Problem Statement :

    All resistances are equal and worth to 360 ohm

    1°)We set between A et B a source of tension E ; [tex]E=U_A_B=12 volts[/tex],
    Determine the intensities of the current in all resistances in this electric circuit.

    2°)Take again question 1 but this time the source of tension is setted between A and D

    3°) Take again question 1 and 2 the source of tension is replaced by a current source delivering an intensity of 20 milliamperes.

    The electrical circuit for solve this problem :

    [URL=http://img388.imageshack.us/my.php?image=sanstitredu6.jpg][PLAIN]http://img388.imageshack.us/img388/5952/sanstitredu6.th.jpg[/URL]http://g.imageshack.us/thpix.php [Broken][/PLAIN]

    2. Relevant equations

    I Haven't idea because I don't understand this lesson. I want absolutely that anyone help me please.

    3. The attempt at a solution

    I need Help because tomorow I Have test but I don't understand this exercise. Thank You
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Nov 18, 2008 #2
    Problems like that can always be solved with 2 Kirchhoffs Laws. Define currents across resistances as I1, I2... and the total current I. Then use V=IR. and http://theory.uwinnipeg.ca/physics/curr/node8.html" [Broken] to get a number of equations for currents, which you can solve simultaneously.
    This always works.
    But there are some other methods, e.g. considerations of symmetry, or Thevenin, Norton theorems.. etc
    Last edited by a moderator: May 3, 2017
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