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Making Electricity


There’s a tactic that I use in school for teaching which is to try and come up with something interesting to show the children but to ask them to predict what’s going to happen, to explain their prediction and then to observe what happens and then to see if their prediction was correct, if so, why, and if not, why, and then for me that’s a testing of understanding and that’s when I think science lessons can work really well and when you as a teacher start to believe that our students have learnt something.

Let me show you an example of what I’m talking about.  I’ve got this down here, I just need to grab it. 

So this is a contraption that I’ve had made and, um, basically I’ve got an LED here buried inside this bit, I’ve got a coil of wire here and I’ve got some magnets here. Now obviously it’s an LED, you would expect it to light up and if you were going to light up an LED you would ordinarily connect it to a power supply, that’s how you make LEDs work. 

I haven’t got a battery here, I haven’t got an obvious source of power, but what I have got are some magnets near the wire and these magnets can be made to rotate like this.  And I guess, ah, any good sixth form student  who studied this bit of the syllabus should be able to tell me what will happen when I spin the magnet – in fact most GCSE students – and that would illustrate that they’d remembered what this process is about, really.  For those of your viewers who don’t know, this is essentially a generator: it’s a model of the kind of thing that is in every single power station in the world and a science student who’s studied this part of the syllabus should be able to predict that when I spin the magnet, the light should light up.  And, indeed, you see, that’s what happens. 

Now, the reason why I love this particular piece of kit is because it’s something that was discovered by my favourite scientist, Michael Faraday, it’s a process called electromagnetic induction and Faraday discovered that if you take some magnets and you move them about near a piece of wire, you get a current in the wire, and that discovery changed the world, it transformed our world, it literally forms the basis of electricity, power generation in all our power stations.

Now a slightly more sophisticated understanding of this allows us to build generators and make them do what we want and that’s the fantastic thing about science: we look at a natural phenomenon, we understand it, we model it and then we can use that phenomenon for our own benefit.  Now you might argue that, you know, generators led to global warming but that’s another conversation…this is a device I use to test my understanding and to illustrate an actual phenomenon and that’s an approach I use in my teaching.