Analyzing a Series Circuit:

- Find the equivalent (total) resistance, R
_{total}, by adding all the individual resistances in the circuit. - Find the current in the circuit using Ohm's Law: I =
V/R
_{total}. - Find the voltage across each individual resistance using Ohm's Law: V = IR.
- Check to be sure that the sum of all the voltage drops across the individual resistances equals the source voltage.

Analyzing a Parallel Circuit:

- If any parallel branch contains more than one resistance, find the equivalent (total) resistance in that branch by adding the individual resistances.
- Find the current through each parallel branch using Ohm's Law:
I = V/R
_{branch}. - Find the current through the voltage source by adding all the currents through the individual branches.
- If any parallel branch contains more than one resistance, find the voltage drop across each resistance using Ohm's Law: V = IR.

Analyzing a Compound Circuit:

- If any parallel branch contains more than one resistance, find the equivalent (total) resistance in that branch by adding the individual resistances.
- Replace each set of parallel branches in the circuit with a
single equivalent (total) resistance.
- If the resistances in each branch are equal, then the equivalent resistance is half of one of the branch resistances.
- If the resistances in each branch are not equal, then

1/R_{equiv}= 1/R_{1}+ 1/R_{2}or R_{equiv}= (R_{1}R_{2}) /(R_{1}+ R_{2}).

- Find the equivalent (total) resistance, R
_{total}, in the circuit by adding all of the series and equivalent resistances. - Find the current through the voltage source using Ohm's Law: I
= V/R
_{total}. - Find the current through each parallel branch.
- If the resistances in each branch are equal, then the current through each branch is one-half the current in the series part of the circuit.
- If the resistances in each branch are not equal, then find the current through each branch using Ohm's Law: I = V/R.

- Find the voltage across each individual resistance and parallel branch using Ohm's Law: V = IR.
- Check to be sure that the sum of all the voltage drops across the individual series resistances and parallel branches equals the source voltage.
- Check to be sure that the sum of the currents through each parallel branch equals the voltage source current.

last update April 13, 2008 by JL Stanbrough