Symbols and components of basic electric circuits

We come across many symbols while travelling .

They are driving symbols.

In driving symbols, different signs indicate different instruction

Symbols are faster way to give information than written instruction.

Similarly different symbols are used in electric circuits.

Before making an electrical circuit, it is first drawn on a paper.

But it is hard to draw all the electric appliances in a single diagram.

Symbols are used for simplicity in drawing a circuit.

An electric circuit is incomplete without wires, but we cannot draw them as shown above

For simplicity, a wire is denoted as a line.

For denoting crossing of wires without any intersection, we draw them as shown above,

If wires intersect forming a junction, then they are denoted as shown above,

Switches are also an important part of household circuits,

In electric circuits, a closed switch is drawn as shown above,

Open switch is drawn like the one above ,

Bulbs used for household purposes have a symbol too.

The symbol of bulb is as shows above,

Like household circuits, there are circuits for laboratory purposes too.

Different symbols for laboratory circuits

Metallic key used in lab to switch on the circuit is called plug key.

Simplified symbol for open plug key is shown above.

Closed plug key is shown as above,

Resistor reduces or resists the flow of electric current,

For denoting resistor we draw the zigzag line connecting two lines.

In laboratory, variable resistor is used for many experiments,

Symbol for variable resistance is resistor cut by an arrow,

An electric circuit is incomplete without a cell. It is the source of energy for the circuit.

For representing cell we draw two vertical lines. Longer one is +ve terminal and shorter one is -ve terminal.

Battery is a device consisting of one or more electrochemical cells

It is denoted by multiple cells in series.

Likewise in laboratory we use measuring tools to measure various electric parameters

Ammeter is used to measure the current in circuit,

Ammeter is denoted by ‘A’ in a small circle connecting two wires.

Voltmeter is used for measuring electrical potential difference in volts.

Voltmeter is denoted by ‘V’ inside small circle between two wires.

Galvanometer is used for detecting and measuring small electric currents.

Galvanometer is denoted by ‘G’ in a small circle connecting two wires.


Symbols are used for representing various components in a circuit.

Symbols make it easier to draw a circuit on paper.

Various representations for household circuit components like switch, bulb are shown above,

Various representations for laboratory circuit components are shown above,

The End