Circuits in Series and Parallel

Circuits and Symbols

An electric circuit is one or more electric components connected to a power supply in a closed loop. There are thousands of different electric components, and millions of different combinations for connecting them together. Below is examples of symbols in common use:-

Power Supplies:-

Output Devices:-

Resistor Devices:-

Measuring Devices:-

Other Components:-

Note - The above only show a small selection of possible symbols, in this course others will be used also.

Drawing Circuits

In Physics, no circuit is ever drawn pictorially (as they actually look), they are always drawn in symbol form. Below is an example of a simple circuit shown in both ways for ease of understanding:-

The circuit above consists of a Cell connected to two lamps.

Series and Parallel Circuits

There are two main ways to connect electric components:-

  1. Series circuit - All components connected in one loop one after the other.

  2. Parallel circuit - Components connected in two or more branches.

The diagram below shows an example circuit for each type:-

As can be seen from the diagram above, each type looks very different. The different layouts cause the circuits to act in different ways.

For example:-

  1. In a Series circuit, if one component breaks, all stop working.

  2. In a Parallel circuit, if one component breaks, the other branches keep working.

This can be seen in the diagram below:-