% Author: Prof. Dr. Matthias Jung, DL9MJ
% Year: 2024
\begin{circuitikz}
    \draw(0,0)
        to [american inductor, name=l1] ++(2,0)
        to [open] ++(1,0)
        to [american inductor, name=l2] ++(2,0); 
    \draw(l1.south) node[anchor=north](){Spule ohne Kern};
    \draw(l2.south) node[anchor=north](){Spule mit Eisenkern};
    \draw[thick] (l2.core west) -- (l2.core east);
    \draw(0,-1.0)
        to [american inductor, name=l3] ++(2,0)
        to [open] ++(1,0)
        to [variable american inductor, name=l4] ++(2,0); 
    \draw[thick,dashed] (l3.core west) -- (l3.core east);
    \draw(l3.south) node[anchor=north](){Spule mit Ferritkern};
    \draw(l4.south) node[anchor=north](){Veränderliche Spule};
\end{circuitikz}