### Become an OU student

An introduction to electronics

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

# Series and parallel networks (combining the laws)

The ordering of the components, and how they are connected, is important in a circuit. For example, two components (here resistors) can be arranged in two different ways, as shown in Figure 11. A circuit in which the current must take a single path, going through first one component and then the other in series, is shown in Figure 11(a); a circuit in which the current splits and takes two parallel paths at the same time is shown in Figure 11(b).

Figure 11 Circuit schematics showing two resistors arranged in (a) series and (b) parallel

By combining Ohm’s and Kirchhoff’s laws, it can be shown that:

• the total resistance of resistors in series is given by

• the total resistance of resistors in parallel is given by

## SAQ 2

In Figure 11, let and . To three significant figures:

• a.What is their resistance in series?
• b.What is their resistance in parallel?