Series-parallel circuits

The series-parallel circuit combines the two previously described types of circuits into one operating system with some distinct advantages. By introducing a load or resistor in series with a parallel circuit, the current flow through the circuit can be controlled (Figure 9).

Series-parallel circuit

To calculate the missing factors in this circuit you must first determine total resistance in the parallel circuit. Since there are only two resistors, you can calculate total resistance by using the formula:

Add this resistance to the remaining 1 ohm (since they are in series) to get total resistance:

Using Ohm’s law you can calculate total current flow.

I = E ÷ R

I = 12 V ÷ 2.3 Ω

I = 5.15 mA

Adapted from: B.C. Campus Line E – Electrical Fundamentals Competency E-1 available for free at https://collection.bccampus.ca/textbooks/line-e-electrical-fundamentals-competency-e-1-describe-the-basic-principles-of-electricity-bccampus-228/