You are forever using things that use electricity - right? Many of them have to be plugged into 'the mains'.
Our homes are wired up to the MAINS - we use MAINS ELECTRICITY every day to make our work easier. Also, the appliances themselves also contain circuits inside them - inside your washing machine, TV, etc. are circuit boards and masses of different circuits.
We know that ELECTRICAL ENERGY is changed into, for example:
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 electrical energy.
Use all this information and your knowledge as you work your way through this worksheet.