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## National STEM Learning Centre

Skip to 0 minutes and 1 second [Modelling and building circuits] Students often struggle when it comes to building circuits as they can’t see the link between circuit diagrams and the practical set up. Students often recognise a circuit diagram, and in most cases this has a cell or power supply at the top, some wires and a component or two set up around the circuit. Research has shown that even turning one of these circuits by 90o can confuse students and they don’t recognise it as the same circuit. By drawing the circuit on a whiteboard you can demonstrate these circuits are the same.

Skip to 0 minutes and 41 seconds By getting students to draw out the circuit diagrams either on whiteboards or the desk, it allows them to then add the components on top and see the relationship between the diagram and the practical setup. This is not just for low ability learners but benefits all students. They can place the components on the diagram and then connect up the wires to ensure the circuit is setup correctly.

Skip to 1 minute and 15 seconds When it comes to more complex circuits such as parallel this is extremely beneficial as the students often get confused as to where to connect the wires and this makes things easier for them. In this circuit we have two routes the current can flow along – the top one and the bottom one, and they can set this up as two series circuits initially, before connecting the two together.

Skip to 1 minute and 42 seconds The two main components used for measuring values are the ammeter and the voltmeter. Students can confuse the two. The ammeter measures how much charge is flowing past a point in one second. One coulomb of charge, passing a point in one second is the equivalent of 1 amp. A voltmeter measures how much energy is being supplied or used by a component. One volt is one joule of energy being given to or used by a coulomb of charge. An ammeter is connected up in series. I always think of it as someone counting people going past a point.

Skip to 2 minutes and 39 seconds If one person goes past in one second it’s one amp, two people is two amps, half a person is half an amp and so on. A voltmeter is connected up in parallel. I think of it as a simple calculator. It measures how much energy per charge there is before, and how much there is after and it tells you the difference. Students often struggle to connect these things properly so using whiteboards with diagrams on can really aid students when it comes to adding these into circuits. Here we can see the voltmeter being connected up over one component, in this case a bulb.

Skip to 3 minutes and 16 seconds For higher ability students you could ask them to work out the voltage across more than one component connected in series.

# Modelling and building circuits

As you can see in the video there are lots of misconceptions and struggles students have when it comes to building electrical circuits. It’s at times like this we turn to models or analogies to help them understand concepts, especially those that are more abstract better.

It is important to remember that analogies can be useful to get messages or principles across, but they can also carry problems leading to misconceptions too. It is important that we try to use a variety of models and analogies and students can see the benefits and pitfalls of each one.

Having whiteboards, paper or even desks that students can draw on means they can make the link between the physical circuit and the more abstract circuit diagram. It is important to stress that this can be used with all students and not just the low ability students.

The value of this approach shows when you begin to rotate the layout of a circuit. Most of the time the power supply is at the top of a circuit with the major components at the bottom. If students see a circuit where this isn’t the case they sometimes struggle with this. Give them the opportunity to build circuits in a variety of ways with the power supply at the bottom nearest them, and components on the side. Do students build parallel circuits where each ‘branch’ is at the side of the other one, instead of being directly below? Do they recognise this won’t make a difference?

## Discuss

Which of the methods described above could you use in your classroom and what do you think the benefits and risks might be with each one?