World of Wires Energy Science-SMART! Home

Electricity travels in a loop called a circuit. A circuit has an energy source and wires; it may also have a load and a switch. There must be no breaks in the loop in order for current to flow. A loop with no breaks is called a closed circuit. An open circuit has a break.

Four Parts of a Circuit

1. Energy Source - source provides the push that makes current move around a circuit.
2. Load - converts electrical energy to another form, in this case a bulb produces light and heat.
3. Wires - two wires connect the energy source and the load.
4. Switch - A switch in the middle of one wire opens and closes the circuit.

When all parts are connected to form a loop it is a closed circuit. Otherwise, it is an open circuit.

Your home is part of a large circuit. The generating plant is the energy source, transmission and distribution lines are the wires that connect the plant to your home, the lights and appliances in your home are the load, and on/off switches on the walls and appliances open and close the circuit.