Here is a circuit with two bulbs. Notice how the bulbs lie along the path of the electricity. The electric current flows through one light bulb, and then the other. This kind of path is called a series circuit. The bulbs are said to be in series. When you open the switch, both bulbs turn off. If one bulb burns out, the flow of electricity stops and the other bulb will turn off too. See a broken circuit on the next page ... Electric Circuits Page 1 | Page 2 | Page 3 | Page 4 | Page 5 | Page 6 | Page 7 Resources