In Science this week we looked at the difference between series circuits and parallel circuits.

The Science Behind the Science

Really basic circuits have a cell, a lamp and a switch. To make the circuit work, these components are connected to the metal connecting wires. When the switch is closed, the lamp lights up. The current will flow all around the circuit. The cell pushes the current around the circuit and as it passes through the lamp, it makes it light up. The current is measured in amps (A), using an ammeter in series. 

There are two types of circuits that we can make: a series circuit or a parallel circuit. Here’s an easy way to remember: if there are branches it’s a parallel circuit and if there are no branches at all, it is a series circuit.  

Just like we see on the TV, series go on and on and on. It is pretty similar in the circuit world.

In a series circuit, you get several components that are lined up one after the other without any branches. If the lamp happens to break or is disconnected somehow, the circuit is broken. This means that all of the components stop working. This is because they are all connected and joined with one another. 

Parallel circuits are a little different. The components in a parallel circuit are connected on different branches of the wire. They are not lined up one after the other. In parallel circuits, there is more than one bulb (resistor) and they are arranged on different paths. Electricity can therefore travel from one end of the cell through different branches to reach the other cell. If a lamp breaks or becomes disconnected in a parallel circuit, the components on the different branches will continue to work. This is because the electricity is flowing through more than one path. If extra lamps are added into a parallel circuit, they do not become dimmer. They stay bright. This is different to a series circuit, where the lamps become dimmer when more are added. Our homes are all wired up with parallel circuit. If one component fails, the others still function.