Drawing circuits

 

 

A simple circuit
When drawing a simple circuit, we typically include a battery, a lamp and sometimes a switch, all connected to each other. See example below:

 

 

Note: What we commonly refer to as ‘battery’ in physics we call this a ‘cell’. The term ‘battery’ is used when you have multiple cells combined. Therefore, if you only have a single cell in a circuit, use the word ‘cell.’ If you have multiple cells, use the word ‘battery'.

We call each part of a circuit a ‘component’. In the example above, both the lamp and the cell are components of our circuit.

 

 

Circuit symbols

Rather than try to draw the image above, we can instead use a circuit diagram to show how the components are connected. Circuit diagrams use straight lines to show the wires and circuit symbols to represent each component in the circuit.

Some common circuit symbols.

 

Let’s look at an example of a simple circuit and its circuit diagram:

 

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When drawing circuits, we use straight lines to represent the wires.

 

Switches

A circuit needs to be complete to work, meaning all the wires must connect the components. Using a switch can let you turn a circuit on and off. If there is a break in the wire, the circuit is not complete and the lamp does not turn on. This is what the switch does.

 

 

In the example above, when the switch is open (off), the lamp does not turn on because the circuit is not complete. But, when the switch is closed (on), the lamp turns on because the circuit is complete.

 

Summary:

 

• We call each part of a circuit a ‘component’.
• In a circuit, a battery is commonly referred to as a cell.
• We use circuit diagrams to show how electrical components are connected in a circuit.
• Individual circuit components are represented using circuit symbols.