Let's build a simple electrical circuit
- bulb,
- cables,
- battery,
Connect the two cables with battery - the first to the electric charge "+" ( metal part with +) and the other to an electrical charge "-". Then two wires connect to the bulb.
After closing the circuit bulb will light.
Electrical current flows from the guides of higher potential to lower potential. To make this possible, in a closed loop must be an element that ensures supply of charge carriers of the points with a lower potential to a higher potential point in a direction opposite to the running of the electric field on them. This requires the input of energy and happens in the elements known as power sources. A source of energy in the circuit can be for example a battery.
An electrical circuit is a special type of network. Has a closed loop giving a return path for the current. If too much current flows through the filament of the bulb, it may burn.