In circuits combining series and parallel connections, the components in one current path without any branch points are in series; the parts of the circuit connected across the same two branch points are in parallel.
To calculate RT in a series-parallel circuit with R in the main line, combine resistances from the outside back toward the source.
When the potential is the same at the two ends of a resistance, its voltage is zero. If no current flows through a resistance, it cannot have any IR voltage drop.
A Wheatstone bridge circuit has two input terminals and two output terminals. When balanced, the Wheatstone bridge can be analyzed simply as two series strings in parallel. The Wheatstone bridge finds many uses in applications where comparison measurements are needed.
The procedure for troubleshooting series-parallel circuits is a combination of the procedures used to troubleshoot series and parallel circuits.
