Circuit DiagramTwo 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, then there is a short circuit and the lamp will not light.
The given visual shows a simple circuit which contains a rheostat, voltmeter, ammeter and a key. A bulb is connected parallel to the voltmeter. When the key is closed, the circuit is complete and the bulb glows.
The below tabular column shows the symbols of some commonly used components in circuit diagrams.