Symbols of Components

Fundamental Components

Resistor: This is represented as a rectangular box or a zigzag line.
Battery: It is represented by one long line and one short line, with the long line indicating the positive end.
Cell: This has a similar symbol to the battery with one long line and one short line.
Switch: It is depicted with a line linked to a dot, showing the switch’s ‘open’ or ‘off’ position.

Advanced Components

Capacitor: It is shown as two parallel lines with a gap in between. A curved line indicates a polarised capacitor.
Inductor or Coil: This is represented by a series of loops or curves.
Diode: The symbol looks like a arrow with a line across its point, indicating the direction of current.
Light Emitting Diode (LED): It is represented by a diode symbol but with two arrows pointing outward to indicate light emission.
Transistor: It is symbolised by a combination of diode symbols.

Additional Components

Ammeter: The symbol is a circle with ‘A’ written inside it.
Voltmeter: It is symbolised by a circle with ‘V’ written inside.
Variable resistor: It presents as a normal resistor symbol with an arrow across it.
Thermistor: The symbol is a rectangle containing the word ‘therm’, placed within a circle.
Light-dependent resistor (LDR): This is depicted as a rectangle with ‘ldr’ written inside, placed within a circle.

These symbols are internationally standardised, so their meanings remain the same irrespective of the context. Knowing these symbols is crucial to analyse and understand circuit diagrams effectively.