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After reading this section you will be able to do the following:

  • Explain what circuit diagrams are used for.
  • Identify what the symbols in the circuit diagrams stand for.

Circuit diagrams are a pictorial way of showing circuits. Electricians and engineers draw circuit diagrams to help them design the actual circuits. Here is an example circuit diagram.

The important thing to note on this diagram is what everything stands for. You see that there are straight lines that connect each of the symbols together. Those lines represent a wire.

This is the Ammeter symbol.

This is the Voltmeter symbol.

This is the resistor symbol.

This is the switch symbol.

This is the battery symbol.

The important thing to remember about this symbol is that the long bar on top represents the positive terminal on a battery while the short bar on the bottom represents the negative terminal.

Below is the actual circuit made from the circuit diagram above. Pay close attention to see how similar the diagram and the real circuit looks.


In the next sub-unit you will be creating your own circuits from a circuit diagram as you learn about what series and parallel circuits are. However, before you do, there are two more symbols you will need to learn.

This is the capacitor symbol.

A capacitor is used to store electrical charge. An example would be a timer. We will not use this symbol but note that this symbol is very common in circuit diagrams.

This is the symbol for the light bulb.


  1. Circuit diagrams are used to show how all the components connect together to make a circuit.