\embed{definition}{&nbsp;}<pre class="fichier">
<div class="variable">
\title\lbrac Noeud dans un circuit lectrique \rbrac
\language\lbrac fr \rbrac
\range\lbrac -5<tt class="w">..</tt>5 \rbrac
\author\lbrac Bernadette Perrin-Riou \rbrac
\email\lbrac bpr@math.u-psud.fr \rbrac
\computeanswer\lbrac no \rbrac
\format\lbrac html \rbrac
\integer\lbrac n = \random(4<tt class="w">..</tt>8) \rbrac
\integer\lbrac m = \randint(1<tt class="w">..</tt>\\n) \rbrac
\text\lbrac somme = 0 \rbrac
\text\lbrac dessin = 
    <tt class="des">xrange</tt> -2,2.2
    <tt class="des">yrange</tt> -2,2.2 \rbrac
\text\lbrac Intensite= \rbrac 
  <tt class=comm>\\for</tt>\lbrac i = 1 <tt class="w">to</tt> \\n \rbrac\lbrac 
    \text\lbrac signe = \randitem(1,-1) \rbrac
    \integer\lbrac I = \\i< \\n? \randint(-10<tt class="w">..</tt>10): - (\\signe)*(\\somme) \rbrac
    \real\lbrac somme = \\somme + (\\I)*\\signe \rbrac
    \text\lbrac Intensite = \\Intensite, \\I \rbrac
    \text\lbrac dessin = \\dessin
     <tt class="des">line</tt> 0,0,cos(2*pi*\\i/\\n),sin(2*pi*\\i/\\n), black \rbrac 
    <tt class=comm>\\if</tt>\lbrac \\signe = 1 \rbrac\lbrac 
    \text\lbrac dessin = \\dessin
      <tt class="des">arrow</tt> cos(2*pi*\\i/\\n)*0.75,sin(2*pi*\\i/\\n)*.75,cos(2*pi*\\i/\\n)*0.5,sin(2*pi*\\i/\\n)*.5, 10,black \rbrac  \rbrac\lbrac 
    \text\lbrac dessin = \\dessin
      <tt class="des">arrow</tt> cos(2*pi*\\i/\\n)*0.5,sin(2*pi*\\i/\\n)*.5,cos(2*pi*\\i/\\n)*0.75,sin(2*pi*\\i/\\n)*.75, 10,black \rbrac  \rbrac
      <tt class=comm>\\if</tt>\lbrac \\i <> \\m \rbrac\lbrac 
       \text\lbrac dessin = \\i >\\n/4 <tt class="op">and</tt> \\i<3*\\n/4? \\dessin
           <tt class="des">text</tt> blue, cos(2*pi*\\i/\\n)*1.6,sin(2*pi*\\i/\\n)*1.6,medium, \\I A
            :
            \\dessin
           <tt class="des">text</tt> blue, cos(2*pi*\\i/\\n)*1.4,sin(2*pi*\\i/\\n)*1.4,medium, \\I A \rbrac
       \rbrac
       \lbrac 
        \text\lbrac dessin = \\dessin
           <tt class="des">text</tt> red, cos(2*pi*\\i/\\n)*1.5,sin(2*pi*\\i/\\n)*1.5,medium, I \rbrac
       \rbrac
   \rbrac
\text\lbrac Intensite = \wims(\nonempty <tt class="w">items</tt> Intensite) \rbrac
\text\lbrac rep = \item(\\m, \\Intensite) \rbrac </div>
<div class="statement">
\statement\lbrac 
  Voici un noeud dans un circuit lectrique aliment en continu :
  &lt;center>
    <tt class=comm>\\draw</tt>\lbrac 200,200 \rbrac\lbrac \\dessin \rbrac &lt;/center>
  Quelle est la valeur de l'intensit \\ (I) manquante ?
    (Vous devez crire l'unit.) \rbrac </div>

<div class="variable">

\answer\lbrac \\ (I) \rbrac\lbrac \\rep A \rbrac\lbrac <tt class="type">type = units</tt> \rbrac
\hint\lbrac Il s'agit de valeurs algbriques. Appliquer la loi des noeuds. \rbrac </div>

 </pre>
