[Music] hi and welcome back to fre science lessons. co.uk by the end of this video you should be able to describe what's meant by a parallel circuit you should then be able to describe the pattern of current flow in a parallel circuit in the last video we saw that an electric current is a flow of electrical charge around the circuit this moves from the negative end of the cell to the positive end however scientists always draw the current in the opposite direction and we call that the conventional current we measure the current using an ameter which we place in the circuit like this now this is a series circuit because it doesn't have any branches so the current can only flow in One path remember that the current is the same all the way around a series circuit in this video we're looking at parallel circuits so let's get started I'm showing you a simple parallel circuit here as you can see a parallel circuit contains branches now what this means is that the current splits some of the current passes through both of the branches so we're going to use ameters to see how the current splits the top ameter measures the current leaving the cell as you can see a current of .3 amp is leaving the cell so let's measure the current in the two branches in the upper Branch we've got a current of 0.1 amp and in the lower Branch we've got a current of 0.2 amp if we measure the current going back to the cell again we can see that this is now .3 amp so here's the key fact about parallel circuits the current in the branches adds up to the total current leaving the cell so here's a question for you to try I want you to work out the current in the lower Branch pause the video now and work this out yourself okay so we know that the current leaving the cell is .5 amp we also know that the current current in the upper branch is 0.3 amp remember that the current in the branches adds up to the total current leaving the cell this means that the current in the lower Branch must be .2 amp here's another question for you you need to work out the current leaving the cell pause the video now and try this question yourself okay so the current in the upper branch is .4 amp and the current in the lower branch is 0.3 amp we know that the current in the branches adds up to the total current leaving the cell this means that the current leaving the cell must be .4 amp plus .3 amp which gives us an answer of .7 amp now in the later video we're going to look at what determines how much current moves through different branches of a parallel circuit remember you'll find plenty of questions on current and parallel circuits in my vision workbook and you can get that by clicking on the link above okay so hopefully now you should be able to describe what's meant by a parallel circuit you should then be able to describe the pattern of current flow in a parallel circuit [Music]