\documentclass[11pt,openany]{book}
\usepackage{amsthm,amsmath,amssymb}
%ایجاد محیط جدیدی که متن مثال و... را در خط پایین بنویسد
\newtheoremstyle{shirin} {} {} {} {} {} {} {\newline} {}
\theoremstyle{shirin}
\usepackage{color}
\newtheorem{theorem}{قضیه}[chapter]
\newtheorem{definition}{تعریف}[chapter]
\newtheorem{example}{مثال}[chapter]
\newtheorem{attention}{نکته}[chapter]
\usepackage{circuitikz}
\usepackage{subfig}
\usepackage{graphics}
\usepackage{siunitx}
\usepackage{xepersian}
\settextfont{Yas}

\begin{document}
\subsection{حل مدارات شامل تقویت کننده عملیاتی (op-amp)}

\begin{figure}[h]
\begin{circuitikz} \draw
(0,0) node[op amp] (opamp) {}
(opamp.+) node[left] {$v_+$}
(opamp.-) node[left] {$v_-$}
(opamp.out) node[right] {$v_o$}
(opamp.down) node[ground] {}
;\end{circuitikz}
\end{figure}
\begin{align*}
\lbrace{&i_{1}=0\\
&i_{2}=0\\
&V_{o}= -k(v_{-} - V_{+})}
\end{align*}
\begin{example}
...در مدار روبه‌رو
\begin{figure}[h]
\ctikzset{ bipoles/length=.98cm}
\begin{circuitikz}[scale =2.1, american] \draw
(0,0) node[op amp] (opamp) {}
(opamp.+) node[left] {}
(opamp.-) node[left] {}
(opamp.out) node[right]{}
%(opamp.+) node[left] -- (-1,-0.25)

(opamp.+) to 
to [short] (-1,-.5)
to [R=$ R_{1} $] (-1,-1.25) -- (-1,-1.5) node[ground] {}
(opamp.-) node[left] -- (-1,0.25)
to [R=$ R_{2} $] (-2,0.25)
to [V=$ V_{s} $] (-2,-1) -- (-2,-1.25) node[ground] {}
(-1,0.25) to [short] (-1,0.75)
to [R=$ R_{3} $] (0.75,0.75)
(opamp.out) node[right] to [short, -*] (1.5,0)
(0.75,0.75) -- (0.75,0)
;\end{circuitikz}
\end{figure}

حل به روش مدل کردن
\begin{figure}[h]
\ctikzset{ bipoles/length=.98cm}
\begin{circuitikz}[scale =2.1, american] \draw
(0,0) to [V=$ V_{s} $] (0,1)
to [R=$ R_{1} $](1,1)
to [short, -*] (1.5,1)
(0,0) to node[ground] (0,-1)
(1.25,1) -- (1.25,2)
to [R=$ R_{2} $] (2.25,2)
to [short] (2.25,1)
to [short, -*]{V_{o}} (3,1)
(2.25,1) to [short] (2,1)
to [cV=$ kV_{d} $] (2,0)
to node[ground]{} (2,-1)
(1,0.75) to [short] (1.5,0.75)
(1,0.75) to [short] (1,0)
to node[ground]{} (1,-1)
;end{circuitikz}
\end{figure}

\begin{align*}
KCL: (V_{1} - V_{s})\setminus R_{1} +i_{1} + (v_{1} - kV_{d})\setminus R_{2} = 0
\end{align*}
\begin{figure}[h]
\begin{circuitikz} \draw
(0,0) node[op amp] (opamp) {}
(opamp.+) node[left] {$v_+$}
(opamp.-) node[left] {$v_-$}
(opamp.out) node[right] {$v_o$}
(opamp.down) node[ground] {}
;\end{circuitikz}
\end{figure}
\begin{align*}
\lbrace{&i_{1}=0\\
&i_{2}=0\\
&v_{-} = V_{+}}
\end{align*}
این المان با عناصر دو سر قابل مدل کردن نیست
\end{document}