Test yourself on electrical circuits in this KS3 Science quiz. Insulators and conductors are words used in relation to electrical circuits. An insulator is a substance that does not allow electricity to pass through. It is useful for making sure that electricity does not get to places where it should not be! Examples of materials that are insulators are plastics and ceramics. Plastics are flexible and can be used on the outside of electrical wires, which need to be able to bend. Ceramics are brittle and inflexible. They are used on electricity pylons to keep the high voltage lines from touching the pylon. Metals are good conductors of electricity, some are better than others. Copper is a much better conductor than steel and is more malleable (bendy) so is a good choice for making wires. But copper is too heavy and weak to use for the large overhead wires that are used to transfer electricity around the countryside so aluminium is used instead.
Components in an electrical circuit can be joined in two ways, series or parallel. In series, they are one after the other (like a TV series, each episode comes after the previous one). If one component in a series circuit breaks, the whole circuit stops working. In a parallel circuit, if one breaks, the rest of the circuit still works.