For basic resistor circuits, there are 3 main rules we use: Ohm's law and Kirchhoff's 2 rules. This example shows a combination circuit with some series and parallel combinations, and outlines a 5-step analysis process that will hopefully become habit. The steps are:
- find the total resistance;
- find the total current with Ohm's law;
- redraw the circuit as a series circuit;
- find the voltage differences across all the resistors in the series circuit;
- go back the original circuit and use the voltage differences to find the currents on each branch, regardless of the branch resistance.
Take a look, and see Doc V if there are any questions at all.