Electrical Symbols, Units and Definitions

Electrical Symbols

Resistor: A symbol represented by a zigzag line. The resistor limits the flow of electrical current.
Battery: The symbol consists of long and short parallel lines. The battery is a source of electrical energy.
Capacitor: A capacitor is symbolised by two parallel lines. It stores electrical energy.
Switch: The switch is shown as a break in a line. It can turn the current on and off.
Diode: The diode symbol is an arrow struck by a line. It allows current to only flow in one direction.
Inductor: Symbolised by a series of curved lines or a looped wire. Inductors generate a magnetic field.

Ampere (A): The Ampere is the base unit of electrical current in the International System of Units.
Volt (V): The Volt is the unit for electrical potential, also known as the ‘voltage’.
Ohm (Ω): The Ohm is the unit of electrical resistance.
Watt (W): A unit of power, the Watt represents energy conversion rate.
Farad (F): The unit of electrical capacitance in the circuit.
Henry (H): The unit for inductance.

Current: Current is the flow of electric charge, measured in amperes.
Voltage: The electrical force that drives electric charge around a circuit, measured in volts.
Resistance: The opposition to the flow of electric current, causing the electrical energy to be converted into heat, measured in ohms.
Power: The rate of energy conversion in the circuit, measured in watts.
Capacitance: The ability of a component to store an electrical charge, measured in farads.
Inductance: The property of an electrical conductor by which a change in current flowing through it induces an electromotive force in both the conductor itself and in any nearby conductors, measured in henries.