Ohm's & Kirchhoff's Laws: Potential difference, current, and resistance satisfy $V = IR$. Kirchhoff's Current Law requires $\sum I_{\text{in}} = \sum I_{\text{out}}$ at every node. Kirchhoff's Voltage Law requires $\sum \Delta V = 0$ around closed loops.
Series & Parallel Equivalents: Series: $R_{\text{eq}} = \sum R_i$. Parallel: $\frac{1}{R_{\text{eq}}} = \sum \frac{1}{R_i}$. For capacitors, parallel $C_{\text{eq}} = \sum C_i$ and series $\frac{1}{C_{\text{eq}}} = \sum \frac{1}{C_i}$.
AC Reactance & Impedance: Capacitive reactance $X_C = \frac{1}{2\pi f C}$, inductive reactance $X_L = 2\pi f L$, total impedance $Z = \sqrt{R^2 + (X_L - X_C)^2}$.
Operating Instructions: Drag components from the toolbox onto the canvas grid, wire terminals together, and inspect voltages and currents with multimeter probes.