What is the term for a circuit that combines both series and parallel sections?

• A. Series circuit
• B. Parallel circuit
• C. Series-parallel circuit
• D. Open circuit

Answer: (C)

Series-parallel circuit is the term for a circuit that combines both series and parallel sections. In such a circuit, some components are in series so the same current flows through them and their voltages add; other components are in parallel so they share the same voltage but current divides among branches. This mixed topology is common and is analyzed by reducing the parallel groups to their equivalent resistance, then treating that result as a single resistor in series with the rest. For example, if a resistor is in series with a parallel pair, you first find the parallel equivalent Rp = (R2*R3)/(R2+R3), then the total resistance is R1 + Rp. The current through the series portion is the same, while at the junction the current splits between the parallel branches according to their resistances. Pure series circuits have all elements in one path; pure parallel circuits have all elements across the same two nodes; an open circuit means no current flows.