Glossary
Current (I)
The rate of flow of electric charge through a conductor. It is measured in Amperes (A).
Example:
When you turn on a flashlight, the Current (I) is the flow of electrons moving through the bulb's filament.
Electrical Power
The rate at which electrical energy is transferred or converted into other forms of energy, such as heat or light, within an electrical circuit.
Example:
A microwave oven uses a high amount of Electrical Power to quickly heat food.
Energy (E)
The capacity to do work or produce heat. In electrical circuits, it refers to the total electrical work done or heat produced over a period of time.
Example:
Your monthly electricity bill charges you based on the total Energy (E) consumed by your household appliances, measured in kilowatt-hours.
Joule (J)
The SI unit of energy and work, defined as the energy transferred when a force of one newton acts over a distance of one meter. In electrical terms, it's the energy consumed by one watt of power over one second.
Example:
Lifting a small apple one meter off the ground requires approximately one Joule (J) of energy.
Ohm's Law
A fundamental law stating that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them (V=IR).
Example:
Using Ohm's Law, an electrician can determine the resistance of a heating element if they know the voltage applied and the current flowing through it.
Power (P)
In physics, power is the rate at which work is done or energy is transferred. In electrical circuits, it's specifically the rate of electrical energy conversion.
Example:
When you calculate the Power (P) dissipated by a resistor, you're finding how quickly it converts electrical energy into heat.
Resistance (R)
A measure of a material's opposition to the flow of electric current. It is measured in Ohms (Ω).
Example:
A toaster's heating coils have high Resistance (R), which causes them to heat up significantly when current passes through, toasting bread.
Voltage (V)
The electric potential difference between two points in a circuit, representing the work done per unit charge to move a charge between those points. It is measured in Volts.
Example:
A car battery provides 12 Voltage (V), which is the electrical 'push' available to drive current through the car's electrical system.
Watts (W)
The SI unit of power, representing one joule of energy transferred or converted per second.
Example:
A standard LED light bulb might consume only 9 Watts (W), while an old incandescent bulb might use 60 W for similar brightness.