- Home
- > Science
- > Additional Science (AQA)
- > Electricity
- > Circuits
Electrical circuits can be represented by circuit diagrams. The various electrical components are shown by using standard symbols in circuit diagrams. Components can be connected in series, or in parallel. The characteristics of the current [current: Moving electric charges, for example, electrons moving through a metal wire. ] and potential difference (voltage) are different in series and parallel circuits.
Circuit symbols
You need to be able to draw and interpret circuit diagrams.
Standard symbols
The diagram below shows the standard circuit symbols you need to know.
 Open Switch |  Closed Switch |  Lamp |  Cell |
 Battery |  Voltmeter |  Resistor |  Fuse |
 Ammeter |  Variable resistor |  Thermistor |  Light dependent resistor (LDR) |
Circuit diagrams
Two things are important for a circuit to work:
- there must be a complete circuit
- there must be no short circuits
To check for a complete circuit, follow a wire coming out of the battery with your finger. You should be able to go out of the battery, through the lamp and back to the battery.
To check for a short circuit, see if you can find a way past the lamp without going through any other component. If you can, there is a short circuit and the lamp will not light.
Work out which of these four lamps will light when the switch is closed. Move your mouse over a circuit, then left click to check your answer.
Links
© MMIX