Aquila Children's Magazine The Electric Issue - Page 5

For the current to flow, it needs a circuit. This is an unending loop of conducting material, so the electron can be passed from one atom to the next. We add appliances into the circuit to make them work, these include everything from games consoles to washing machines. Cable grip Neutral terminal Earth terminal Live terminal Fuse Let’s take a look at electricity in the home. Remember that electricity can be VERY dangerous, so don’t put anything into the socket or take anything apart. You could get a nasty shock. The outside of a wall socket is mostly made of plastic, which is a good insulator. The plastic covering reduces your chance of getting an electric shock. Inside the socket are metal contacts, which are supplied by the mains electricity supply. You can usually see them by looking at where the top pin of the plug goes in. Remember not to touch! In modern socket covers, the lower two (and most dangerous) holes are covered by protective shutters. These open automatically when the top pin of the plug is inserted. A plug also has an insulating plastic case. The metal pins are usually made of brass (a good conductor) and these touch the metal contacts inside the wall socket. Your plug may have black insulation on the pins, this is to reduce the chance of touching a live pin when plugging in. When you plug something in, the electrical current flows from the mains to the socket and then to the pins of the plug. It travels through the internal circuit of the appliance before going back to the wall socket again. This makes a circuit. Each pin of the plug has a wire connected to it, the live or line (brown) wire has a fuse between the wire and the pin, this breaks the circuit if too much current flows. It protects you, the circuit and the appliance. The live wire carries the current from the mains supply into the appliance and the neutral (blue) wire completes the circuit, carrying the current away from the appliance back to the mains. The earth (green-yellow) wire is there for safety. It creates a safe route for the current to flow through if the live wire touches the casing, and stops you from getting an electric shock. Many modern plugs are completely sealed units, but older plugs can safely have the cover removed with the help of an adult, so long as they are unplugged from the wall. If you are looking at a UK plug, the insides will look similar to the diagram but the wires might be different colours. Wires made before 2004 had red insulation on live wires and black insulation on neutral wires. Plugs from different countries vary a little, but you can easily find labelled diagrams of them online. Electricity can be very dangerous. If it flows through your body it can disturb the electrical messages in your muscles, especially your heart. It will change the rhythm of your heart or maybe stop it altogether. So how are birds able to sit on electricity cables? It’s because electricity will always take the easiest route – usually along a nicely conductive wire. The current would need to take a diversion through a less conductive path to get through the bird, so the electricity stays in the wire. If the bird was able to flap its wings and touch another electric wire with a different voltage, then it would likely get frazzled, as the bird has become a path for the electricity to reach a place of different voltage. This is why electricity cables are usually high off the ground and with plenty of space between the wires! 5