如何标记组件，以及如何更改 vt 和 emf 的极性

Question

\begin{circuitikz}[american voltages]
\draw
    (0,0) to [V, l_=$emf$](0,5)
    to [L, l=$L \frac{di}{dt}$](3,5)
    to [R, l=$Ri$](6,5)
    to [short, i_=$ i $](7,5)
    to [C, l=$X_{c}$](11,5);
\draw (0,0) to (11,0)
    to [open, v=$v_{t}$](11,5);
\end{circuitikz}

Answer 1

\documentclass{article}
\usepackage{tikz}
\usepackage{circuitikz}
\begin{document}

\begin{circuitikz}[american voltages]                                   
\draw (0,0) to [V, l_=$emf$] (0,5)
            to [L,l=$L$, v=$L \frac{di}{dt}$] (3,5)
            to [R,l=$R_c$, v=$Ri$] (6,5)
            to [short, i_=$ i $] (7,5)
            to [C, l=$X_{c}$, v=$\frac{1}{C}\int_{0}^{t}i dt$](11,5);
\draw (0,0) to (11,0)
      (11,5) to [open, v=$v_{t}$](11,0);
\end{circuitikz}
\end{document}