Thanks team. The third socket, the Earth socket is sometimes called the ‘grounding socket”. Lets try to make our own circuit to find out a little bit about this.
You would need a battery, some wire, a light bulb in a bulb holder and let’s say a cup with some damp sand in it.
Push the earth wire into the wet sand and see what happens.
The Earth socket on a UK plug is designed for problems where the electricity that you are using becomes unsafe, for example a wire inside a washing machine touches the case that the machine is contained in. The case it attached to rubber, non conducting wheels. You touch the case, with your leather soled shoes and you then get an electrical shock. If the case is attached to the earth wire the electricity finds an easy route to escape and this causes safety switches to open in the fuse box of the circuit. In the old days it would make a fuse melt and thus break the circuit.
The Earth socket is therefore a safety socket. Lots of appliances nowadays are so well insulated (protected) that an Earth protection is unnecessary. Some plugs have a plastic third pin. Two pin plugs have never had this additional protection.
Another experiment that you might like to try is changing the wet sand for other materials. Try leather, metals, china, dry sand, cloth ….. all sorts of materials. What an experiment! Brilliant.
DO NOT EXPERIMENT WITH MAINS ELECTRICITY