Combination Circuits

Equivalent resistance rules can be applied to combination circuits. When analyzing a combination circuit, the first step is to find the total resistance. Once the total resistance is found, the total current can be calculated using Ohm’s Law. The currents and voltages of the individual resistors are found by applying the rules for voltage and current in series and parallel. Elements in series have the same current, while elements in parallel have the same voltage.  By using these rules along with Ohm’s Law, all of the voltages and currents can be found. 

Kirchoff’s Loop Rule tells us that the sum of the voltage drops must equal the voltage of the battery. Kirchoff’s Junction Rule tells us that the current that goes into a junction must come out. These rules help us confirm the results of calculations when analyzing circuits.