Series Voltage-Sharing Three-Row Scan - Capacitors & Stored Charge Step by Step

Series capacitors share charge, so each voltage drop is charge divided by that capacitor's capacitance. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Series capacitors share one charge ledger

In a series chain, the same stored charge passes through each capacitor ledger. Voltage then divides as charge divided by each capacitance.

V_a=\frac{Q}{C_a}\qquad V_b=\frac{Q}{C_b}

The two voltage drops add to the source

Hold charge at 8 coulombs. Each row computes the two capacitor voltages separately, then adds them to the source voltage.

\begin{array}{c|c|c|c|c}C_a&C_b&V_a&V_b&V_s\\2\ \text{F}&2\ \text{F}&4\ \text{V}&4\ \text{V}&8\ \text{V}\\2\ \text{F}&4\ \text{F}&4\ \text{V}&2\ \text{V}&6\ \text{V}\\4\ \text{F}&4\ \text{F}&2\ \text{V}&2\ \text{V}&4\ \text{V}\\\end{array}

The equivalent capacitor gives the same source

The series equivalent is allowed only because the source voltage from the two drops equals charge divided by equivalent capacitance.

V_s=V_a+V_b=\frac{Q}{C_{\text{eq}}}