注意代码块是tikz而不是latex
\usepackage{circuitikz}
\begin{document}
\begin{circuitikz}
\draw (0,0) to[R, l={label: $R_1$}, f={flows: $i_1$}, a={annotations: $1\Omega$}] (5,0);
\draw (0,3) to[R, l=$R_2$, i={currents: $i_1$}, v={voltages: $1V$}] (5,3);
\end{circuitikz}
\end{document}
\usepackage{circuitikz}
\begin{document}
\begin{circuitikz}[american voltages]
\draw
(0,0) to [short, *-] (6,0)
to [V, l_=$\mathrm{j}{\omega}_m \underline{\psi}^s_R$] (6,2)
to [R, l_=$R_R$] (6,4)
to [short, i_=$\underline{i}^s_R$] (5,4)
(0,0) to [open, v^>=$\underline{u}^s_s$] (0,4)
to [short, *- ,i=$\underline{i}^s_s$] (1,4)
to [R, l=$R_s$] (3,4)
to [L, l=$L_{\sigma}$] (5,4)
to [short, i_=$\underline{i}^s_M$] (5,3)
to [L, l_=$L_M$] (5,0);
\end{circuitikz}
\end{document}
\begin{document}
\begin{tikzpicture}[domain=0:4]
\draw[very thin,color=gray] (-0.1,-1.1) grid (3.9,3.9);
\draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$};
\draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$};
\draw[color=red] plot (\x,\x) node[right] {$f(x) =x$};
\draw[color=blue] plot (\x,{sin(\x r)}) node[right] {$f(x) = \sin x$};
\draw[color=orange] plot (\x,{0.05*exp(\x)}) node[right] {$f(x) = \frac{1}{20} \mathrm e^x$};
\end{tikzpicture}
\end{document}