What is a ground? What is a happening to need a ground?
In: Physics
Take the earth is a giant neutral body, where there will never be any charge despite any flow of electrons out of or into the earth. A ground is simply when a electricity-conducting material is connected directly to this earth. Then, the material is known as grounded. The ground plug in your sockets already do this.
Usually the ground pin on your plugs are connected to the casing of your electrical appliance, especially when it’s made of an electricity-conducting material, like metal. That’s why Samsung phone chargers (at least in the UK) have plastic ground pins that don’t do anything, since the charger system of a smartphone has a non-conductive material on the outside.
The ground is there for a good reason. If a fault happens, say the live or hot wire is exposed and touches the metal casing, electricity is shorted through the casing, since electricity always takes the path with the lowest resistance. Without ground, this metal casing will become ‘hot’, and anyone who touches the casing will get an electric shock. The ground wire prevents this by allowing the electricity to flow from the casing to ground. As the resistance of the ground wire is low, this results in a huge surge of current through the live wire, casing and ground wire. This is why the appliance also includes a fuse placed on the live wire, which blows in the surge of current, opening the circuit and preventing the casing from going live.
My explanation isn’t the best, but I hope this helps.
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