An electric appliance is provided with a three-core flexible cable.The insulation on the three wires is of different colours.The old conversion is red for live,black for neutral and green for earth.The new international convention is brown for live,light blue for neutral and green(or yellow) for earth.
HIGH TENSION WIRES:
Each wire in a cable is capable of withstanding a specific value of current.If current exceeds this limit(due to short circuiting or high voltage fluctuations), the wire may burn due to excessive heating, and it may cause a fire.To avoid it, for high voltage and heavy current,special wires,called high tension wires, are used.These wires are made by twisting a number of thin wires so as to provide a large surface area.Thus the high tension wires have low resistance.
