Our homes are wired up to the MAINS - we use MAINS ELECTRICITY every day to make our work easier. The appliances also contain circuits.
We know that ELECTRICAL ENERGY is changed into:
Because MAINS ELECTRICITY is very powerful and dangerous, we use materials which insulate us and keep us safe when we are using electrical appliances. These materials are NON-METALS, for example: plastics and are used to cover the metal wires which conduct the elecrtical energy.