The same current flows through each part of a series circuit. If the circuit is broken at any point there won’t be any current that will flow. In the above circuit, electricity flows from the battery to each bulb, one at a time, in the order they are wired to the circuit. In this case, if one of the bulbs blew out, the other bulb would not be able to light up because the flow of electric current would have been interrupted. In the same way, if one of the bulb was unscrewed, the current flow to both the bulbs would be interrupted. If the circuit were a string of light bulbs, and one burned out, the remaining bulbs would also turn off