input fks
verbatimtex
%&latex
\documentclass[9pt]{extarticle}
\usepackage[utf8]{inputenc}
\usepackage{fkssugar}
\begin{document}
etex
 
prologues:=3;
u:=1cm;
 
beginfig(1);
u:=1cm;
def rezistor(expr X,Y) =
   s:=4;
   t:=0.2;
   draw X--(X+1/s*(Y-X));
   draw t*u*unitvector(Y-X) rotated 90 shifted (X+1/s*(Y-X)) -- t*u*unitvector(Y-X) rotated -90 shifted (X+1/s*(Y-X)) -- t*u*unitvector(Y-X) rotated -90 shifted (X+(s-1)/s*(Y-X)) -- t*u*unitvector(Y-X) rotated 90 shifted (X+(s-1)/s*(Y-X)) -- cycle;
   draw (X+(s-1)/s*(Y-X))--Y;
enddef;

q:=4u;

rezistor((0,q),(q,q));
rezistor((q,0),(q,q));
rezistor((2q,q),(q,q));
rezistor((2q,q),(2q,0));
rezistor((2q,q),(3q,q));
rezistor((3q,q),(3q,0));
rezistor((3q,q),(4q,q));
rezistor((4q,q),(4q,0));
draw (4q,0)--origin;
drawarrow ((4q,q/3)--(4q,2*q/3)) shifted (-q/8,0);
label.rt("1A", (4q,q/2)) scaled 2 shifted -(4q,q/2);
r:=15;
unfill fullcircle scaled (q/r);
draw fullcircle scaled (q/r);
unfill fullcircle scaled (q/r) shifted (0,q);
draw fullcircle scaled (q/r) shifted (0,q);
label("U=?",(0,q/2)) scaled 2 shifted -(0,q/2);



endfig;
verbatimtex
\end{document}
etex
 
end;