The fuse is a safety device comprising a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level. It is made up of metal with a low melting point so that the current overload does not damage the electrical appliances in our household. Electric fuse has a body made of ceramic and two points for connecting the fuse wire.

Insulators are the materials which do not allow electricity to pass through them. Thus, they do not possess enough free electrons to conduct electricity and are called as poor conductors. Insulator gives high resistance to the flow of charge on the application of external voltage. Wood, plastic, rubber, cloth, paper are a few examples of insulators.

Batteries are a collection of one or more cells whose chemical reactions create a flow of electrons in a circuit. It will have positive and negative terminals on either side. They can be used to power several electrical devices like torches, electric cars, mobile phones, laptops, etc.