documentclass[11pt]{article}

usepackage[margin=1in]{geometry}
usepackage{graphicx}
usepackage{mathrsfs}
usepackage[english]{babel}
usepackage{circuitikz}
usepackage{color}
usepackage{listings}                       % for codes
usepackage{amsmath,indentfirst}            % for matrices
usepackage{amssymb}
usepackage{array}
usepackage{tikz}                           % for flowcharts
%usepackage[latin1]{inputenc}
usetikzlibrary{shapes.geometric, arrows, shapes.arrows,decorations.pathmorphing, matrix,chains,scopes,positioning,fit,shapes.gates.logic.US, shapes.gates.logic.IEC, calc,
decorations.markings,arrows.meta,bending}
usepackage{tabu}
usepackage{siunitx}
usepackage{caption}
usepackage{textcomp} % avoid the warning from gensymbol's package
usepackage{gensymb} %for the degree symbol
usepackage{pgfplots}
usepackage{polynom}
pgfplotsset{compat=1.11}

begin{document}

begin{center}
    begin{tikzpicture}[baseline=(current bounding box.center)]
    draw (0,0)
    to[short,o-] (1,0)
    to[R] (2.5,0)
    to[L] (4,0)
    to[short,-*] (5.5,0)
    -- (7,0)
    (8,0) node[transformer core] (T) {} (T.B1) -- (9.5,0)
    to[L] (11,0)
    to[R] (12.5,0)
    to [short,-o] (13.5,0)
    (5.5,0) -- (5.5,-0.4)
    -- (5.9, -0.4)
    to[L] (5.9,-1.9)
    -- (5.5,-1.9)
    -- (5.5,-2.3);

end{tikzpicture}
end{center}
end{document}