G5-Electric Lighting: History and Function 750L- 03_lower level

Electricity must have a source. For your home, it is probably a nearby power station. Switches control the electricity that comes to your home. These switches open or close circuits. Circuits are the paths that the current flows through. When you turn off a light, you flip a switch into the “off” position. This opens the circuit and creates a gap.

An open circuit means there is no continuous path for the current to flow. For current to flow through a circuit, it must be closed or continuous. In other words, electricity must have an unbroken path to follow. To turn on a light, you flip a switch to the “on” position. This closes the circuit, allowing electricity to flow through a continuous path.

The current follows a path or wire. Wires are usually made of copper or other metal. Metals like copper allow a current to flow easily through them. They are called conductors. Some materials resist the flow of electricity. These materials are called insulators. You may have noticed the wires in your home are wrapped in plastic. The switches you touch to turn on the lights are also made of plastic. Plastic is an insulator. Insulators keep you from getting shocked when you touch the switch.

So the next time you flip on a light, think about the Science that went into making it happen.