Drawing Circuits

Simple Circuits

When drawing a simple circuit, it will typically include a battery, a lamp and at times a switch, all connected to each other. Something similar to the diagram below.

Illustration of a simple circuit comprising a rechargeable battery labelled "RECHARGE" connected to a glowing light bulb. The battery, positioned at the top, has a positive terminal, and the wires from both ends loop down to the base of the illuminated bulb. The glowing bulb indicates the flow of electricity from the battery.

It is important to note: What is commonly called a ‘battery’ in everyday language is referred to as a ‘cell’ in physics. The term ‘battery’ is used when you have multiple cells combined. So, in your circuit, if you only have a single cell, use the word ‘cell.’ If you have multiple cells, you can use the word ‘battery.’

We call each part of a circuit a ‘component,’ which means that in the diagram above, both the lamp and the cell are components of our circuit.

If you always drew circuits like this, it would take too long and it can be difficult to draw. Instead, each circuit component is given a symbol, which makes it easier to draw circuits.

Below are some common symbols you will be required to use:

Electrical circuit symbols

Below are some electrical circuit symbols that are important to remember.

Illustration of standard electrical circuit symbols. On the top row, from left to right, there's an open switch represented by two circles connected by a straight line that doesn't meet in the middle, a resistor depicted as a straight horizontal line with a rectangle perpendicular to it, and a lamp shown as a circle enclosing a cross. On the middle row, there's a closed switch represented by two circles connected by a continuous straight line, a cell symbolised by a long vertical line (positive) and a shorter vertical line (negative) with a horizontal line attached to each vertical line, and an ammeter with a circle enclosing the letter 'A'. On the bottom row, there's a fuse depicted as a rectangle with a line going through it, a battery with two sets of vertical lines (one long and one short) separated by dashed lines representing multiple cells, and a voltmeter represented by a circle enclosing the letter 'V'.

Let’s look at an example of a simple circuit below.

Two basic electrical circuits depicting the operation of a switch. On the left, the circuit is 'On' with a glowing bulb connected to a blue battery via gold wires and a closed green switch. On the right, the circuit is 'Off' with a non-illuminated bulb, connected in a similar manner, but the green switch is open, breaking the circuit.

  • Keep in mind that this circuit includes a switch

We can replace the circuit components with circuit symbols to create a much simpler diagram, which you can see below.

A visual comparison of two electrical circuits, both in realistic and schematic forms. The top left shows a realistic 'On' circuit with a glowing bulb, blue battery, gold wires, and a closed green switch. Directly below is its schematic representation with a closed switch and battery symbol. The top right depicts a realistic 'Off' circuit with a non-illuminated bulb and an open green switch. Its corresponding schematic below displays an open switch, represented by a break in the line.

When drawing circuits, straight lines are used to represent wires.

Switches

For a circuit to work, it has to be complete, meaning all the wires must connect the components properly. Using a switch can allow you to connect and disconnect a circuit. If there is a gap in the wire, the circuit is incomplete and the lamp does not light up. This is the purpose of the switch.

When the switch is open (off), the lamp does not light up because the circuit is incomplete. In contrast, when the switch is closed (on), the lamp lights up because the circuit is complete.