Electromagnetic Induction

A brief demonstration and explanation of electromagnetic induction, the phenomenon at the heart of all electricity power stations. The "generator" is a home-made prop, a prototype that doesn't work very well. I had it built because I felt it was a more effective demonstration than getting an ammeter needle to flicker as is done in traditional classroom demonstrations of this effect. One of my students is building a more sophisticated version with gears, interchangeable magnets and coils, and 4mm connectors to allow it to be connected to a voltmeter - which should make it much better for teaching purposes.

I use the prop to introduce EM induction to students - it is genuinely surprising to some of them to see that you can generate electricity in this way and for them to learn that this is essentially the same thing that goes on in a power station. I feel this works better than diving straight into talking about wires cutting lines of flux etc. Of course, I then go on to explain the topic in more detail, but this simple demonstration serves to supply the basic points they need to learn at GCSE in a memorable way.

Category:

Education

Tags:

• Physics
• Teacher
• Science
• Electricity
• Current
• Voltage
• electromagnetism
• energy
• power
• educational
• GCSE
• Revision

[runnerbeanz52]

A nice introduction to EM Induction, Alom. Who made the kit?

[Sciencefilms]

@runnerbeanz52 My crappy design - I wanted magnets to be visible, hence outside coil. Built by carpenter friend of mine. Email me if you want contact details. A student of mine is building a better designed version (gears, changeable magnets / coils) for his A2 DT project. Will stick a film of it up when it's done.

[comp144]

What microphone did you use to shoot this?

[Sciencefilms]

@comp144 From Jonathan, the director: "Audio is from a beaten-up Sennheiser lapel mic (radio), recorded into a cruddy little audio recorder (MicroTrack II - absolutely *not* recommended) and resynced afterwards."

[jameswinmill]

Im sure if you won the prize would go towards the £50,000 production fees to make the film...

[Sciencefilms]

@jameswinmill Flattered that you think we spent so much money.

[declanfleming]

9 people deserve to read by candlelight for the rest of their life

[TheZenPerspective]

He looks like a more intelligent version of Paul Potts.

[ibphysicshelp]

@kitenyos .... Of course the issue is a bit more complicated (for eg. you cannot concentrate too many electrons at one end as they repel each other) but I hope my brief answer points you in the right direction.

[ibphysicshelp]

@kitenyos Hi there. I'll try to give you a very brief answer. When an electric charge (e.g. electron) moves relative to a magnetic field, it experiences a force. Assume that the electron is in metal wire and it can move. The force makes the electrons moving towards one end of the wire/loop which becomes "-" and the other end is going to be positively charge and thus the "+" "terminal"....

[crazym24]

How do magnets work?

[ibphysicshelp]

Nice, simple and clear introduction to a topic that quite a few students find it difficult. Great filming and editing too!

[kitenyos]

Why does changing magnetic fields near a coil of wire produce voltage?

[volvoxpl]

You can add on/off switch to break circuit and show (might be harder on video than in real life) that magnet wheel spins with ease when not generating electricity, but requires more energy to spin it when electricity for bulb is generated (circuit is closed). I didn't realized this fact when i was young ;)

[Nomisnitram]

Bacon sandwich? Nice one Alom, great little vid! Catch you soon bro, Si and Sof x

[Nomisnitram]

Bacon sandwich? Nice one Alom! Catch you soon bro