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);
drawarrow ((4q,q/3)--(4q,2*q/3)) shifted (-q/8-q,0);
drawarrow ((4q,q/3)--(4q,2*q/3)) shifted (-q/8-2q,0);
drawarrow ((4q,q/3)--(4q,2*q/3)) shifted (-q/8-3q,0);

drawarrow ((4q-q/3,q)--(3q+q/3,q)) shifted (0,-q/8);
drawarrow ((4q-q/3,q)--(3q+q/3,q)) shifted (-q,-q/8);
drawarrow ((4q-q/3,q)--(3q+q/3,q)) shifted (-2q,-q/8);
drawarrow ((4q-q/3,q)--(3q+q/3,q)) shifted (-3q,-q/8);



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);
label.top("1A", (4q,q/2)) scaled 2 shifted -(4.5q,-.05q);
label.top("3A", (4q,q/2)) scaled 2 shifted -(5.5q,-.05q);
label.top("8A", (4q,q/2)) scaled 2 shifted -(6.5q,-.05q);
label.top("21A", (4q,q/2)) scaled 2 shifted -(7.5q,-.05q);
label.rt("2A", (4q,q/2)) scaled 2 shifted -(5q,q/2);
label.rt("5A", (4q,q/2)) scaled 2 shifted -(6q,q/2);
label.rt("13A", (4q,q/2)) scaled 2 shifted -(7q,q/2);

label.top(btex A etex scaled 1.5,(4q,q));
label.top(btex B etex scaled 1.5,(3q,q));
label.top(btex C etex scaled 1.5,(2q,q));
label.top(btex D etex scaled 1.5,(1q,q));
label.bot(btex E etex scaled 1.5,(4q,0));
label.bot(btex F etex scaled 1.5,(3q,0));
label.bot(btex G etex scaled 1.5,(2q,0));
label.bot(btex H etex scaled 1.5,(1q,0));




endfig;
verbatimtex
\end{document}
etex
 
end;