Circuit Diagrams

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.

Common circuit diagrams include a voltage source, current and voltage readers, and/or electrical loads that use the electrical energy of the circuit.

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.

 ammeter symbolThis is the Ammeter symbol.

 voltmeter symbolThis is the Voltmeter symbol.

 resistor symbolThis is the resistor symbol.

 switch symbolThis is the switch symbol.

 battery symbolThis is the battery symbol.

The important thing to remember about the battery 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.

An engineer would draw a symbolic circuit diagram so that it is easily read by other engineers.                It would take too much time to attempt to illistrate a realistic image of the circuit.

In the next pages you will learn about what series and parallel circuits are. However, before you do, there are two more symbols you will need to learn.

 capacitor symbolThis is the capacitor symbol.

A capacitor is used to store electrical charge. An example would be a timer. 

 light bulb symbolThis is the symbol for the light bulb.


  1. Circuit diagrams are used to show how all the components connect together to make a circuit.
  2. Each component has its own dedicated symbol that is used in circuit diagrams.