Webinar: Top Five Static Electricity Demos

20 October 2016
Tuesday 25 October, 8pm

Here’s the fourth of our 2016/17 webinar series:  Top Five Static Demos.

This session is run by our very own Dave Cotton, physics teacher, TalkPhysics Editor, and IOP Physics Network Coordinator in Preston.

Add your questions and comments below for your free copy of Physics Education on static electricity.

Got an idea for a physics webinar?  Let us know – and you could host the next one. 

PS – TalkPhysics webinars are © IOP and can be freely used in schools.  Please do get in touch if you’d like to modify or use them for commercial purposes.

  1. Sadia Nasim 3 years ago

    I’m excited to be a part of webinar

  2. Ehab Abouelela 3 years ago

    It is interesting, how can I joing the webinar ?

  3. Tom Johns 3 years ago

    The tension is building up….

  4. rajinder mackay 3 years ago

    I love the salad bowl accelerator, I am looking forward to trying out at school 🙂

  5. Tom Johns 3 years ago

    my students love the dancing paper – I ask them to try it at home to show parents etc.

  6. David Cotton 3 years ago

    Hi Rajinder, I got my bowl for 50p. The aluminium tape cost about £7 there is a lot more you can do with it. Here is my setup


  7. David Cotton 3 years ago

    Hi Tom, Issac Asimov is a very popular author in my college and the Left Hand of the Electron book is very popular

  8. Tom Johns 3 years ago

    Our VdG seems to be very temperamental – any tips on storage  etc?

    • David Ferguson 3 years ago

      From an article I wrote on a technician’s website:

      Ideally the unit should be kept in a dry environment, a “hot cupboard” is ideal.

      The Van der Graaff unit, discharge sphere, and motor unit should be taken out and ensured that it is in good order. Pay close attention to the belt, this should be cleared of any debris and cleaned if necessary (IMS or isopropanol {check risk} on a lint free cloth, only if there is sufficient time before use). You can force dry with a small Hair Dryer (Note the risk if flammable vapour is present with sparks!).
      The pulleys should also be cleared of debris. The metal combs that take the charge from the rubber belt should also be in good order. An aluminium dome should be cleaned with a metal polish, “T-Cut” or preferably “jewellers rouge” to improve spark if time allows, as the cleaning is time consuming Chrome plated domes require more careful treatment and cleaning with alcohol is recommended.
      It has also been noted that the thing that most often causes the VDG to fail or produce a weak charge is the support pillar(s) not being clean (allowing charge to seep away). Clean carefully before use, and don’t handle after cleaning.
      Always remove the rubber belt when not in use and store carefully in a plastic bag, that way it stays clean and un-stretched. Be careful not to damage the ‘brushes’ when you remove or re-install the belt.”

  9. David Cotton 3 years ago

    I find my VdG works best when I adjust the comb to only just touch the belt. I also keep the belt clean and dust free.

  10. Dan Cottle 3 years ago

    Thanks Dave – really enjoyed that!

  11. David Ferguson 3 years ago

    I haven’t seen the lentil/semolina tube GLE before. Impressed.

    Would like to try with an earthed copper tube for comparison.

  12. David Cotton 3 years ago

    Thanks Dan

  13. David Cotton 3 years ago

    A great thing to show with a VdG is the origin of all the phones and their signals by Marconi and his radio waves made by spark. My Dad was a sparky!

  14. Philippa Wallington 3 years ago

    Thanks Dave are the instrctions for making the salad bowl accelerator any where?

    Also hadn’t though of demonstrations static for fusion. Can anyone think of other places at gcse it could be used?


  15. Dan Cottle 3 years ago

    I like the linear accelerator demo – does the ball move faster the longer the length you use?

  16. David Cotton 3 years ago


    Here was the set up I first saw. They have coulomb meters under them


    • David Ferguson 3 years ago

      Great-Seems to show what I would expect (just too much glare on the copper tube C.meter!). The use of C.meters  would be more convincing.

  17. Phil Furneaux 3 years ago

    well done dave

    great show

    just a question about the back drop

    1. i was expecting a panda to come out of the bamboo backdrop … maybe next time??
    2. and i hope my CD was amongst your collection!!!??
  18. Emma Hewitt 3 years ago

    Thanks for this – I’ve not seen the paper cuttings/ foil trays on the VdG before. Students are going to love it

  19. Chris Watson 3 years ago

    Great video, thank you David.

    I once saw a guy put a Barbie doll on top of the VdG so I like to do that too!

    I vaguely remember watching a video about how to make a salad bowl accelerator before but can’t find it now. Do you happen to have a link handy please? Thank you!

  20. Rui Montezuma 3 years ago

    Fantastic experiments: simple, cheap, safe, visible and real time effects. Experiments could be done in any school. I appreciated the recommendation of reading a few books about the History of Physics.

    Regarding the apparatus: would it be possible to give some reference were to buy some of the ost specific materials used in the several apparatus?

  21. David Cotton 3 years ago


    Hi Philippa
    Good instructions here http://highheelsinthelab.blogspot.co.uk/2016/04/how-to-make-particle-accelerator-in-bowl.html

    Suzie Sheehy is also worth following on twitter @suziesheehy
    Here is her great interactive talk on particle detectors


  22. Alessio Bernardelli 3 years ago

    Nice one Dave! Really good demos. The lentils and electrode demo was really interesting and a good link with some areas of the curriculum.

  23. David Cotton 3 years ago

    Hi Alessio, There was some great questions in the GCSE papers about re-fuelling aircraft.
    In fact BMW’s mini was recalled because of poor earthing in the fuel line and there are lots of powder factory explosions documented.


  24. Sheila Dell 3 years ago

    Students like moving a Coke can with a balloon….

  25. David Cotton 3 years ago

    Hi Sheila

    my favourite balloon static demo is this one. Balloon pump is necessary to generate the friction.

  26. David Keenahan 3 years ago

    Thanks David,  I liked the salad bowl accelerator particularly, as i hadn’t seen it in action before.

    • David Cotton 3 years ago

      Hi David, I am always keeping my eye out for a really gently sloping bowl. It would work so much betterAQUADAG 2AQUADAG 1

      If you rough up the table tennis balls with sand paper they hold the aquadag better

  27. David Cotton 3 years ago

    Hi Emma, I was asked by a student if they would lift off my head. So we tried it.

  28. David Ferguson 3 years ago

    Another demo for electrostatics

  29. David Cotton 3 years ago

    HI David to embed click the text box next to visual then insert embed code. You get the embed code by right clicking the YouTube vid

  30. David Cotton 3 years ago


    Hi Rui I love teaching the history of the physics and its chronology. I have a wimshurst generator and love showing Franklin’s Bells.


    This is one of my all time favourite GCSE questions
    Franklins bell examfranklins bells

  31. David Cotton 3 years ago

    I was really impressed with these dinner table cannons. Fired across the dinner table in a previous era!cannon

  32. Steve Long 3 years ago

    Great webinar Dave, thanks for putting the show together. Particularly liked the linear accelerator.

  33. Philip Brady 3 years ago

    Thanks David for all the helpful ideas. I have just started static electricity with my sixth year Leaving Cert Students so this presentation is very timely-normally I get lots of ideas and forget to use them if not on that topic! As well as the demonstrations, I appreciated the applications to the everyday-my 22 yr old son who was my physics student a few years ago and now working in electronics loves minis so the recalled minis story is one I am eager to share with him.

    One thing I always forget and was hoping you might mention was which rod is the polythene and which the perspex-i.e. one is transparent and the other white? I liked how you hung these from two strings for extra stability- I was using the rods today on clock glasses , stuck to the centre with blutack, and the students got them to spin very impressively.Best wishes with your very entertaining, informative and friendly teaching.


  34. Tom Johns 3 years ago

    Does anyone else feel when rubbing the plastic rod with the cloth all students are sniggering?

  35. Heather Evans 3 years ago

    The demonstrations are fun for students to watch, but I also liked the information about applications (the fuel pipe problems in the mini).  I also agree that it is helpful if students can learn something about the scientists who made the various discoveries so that they have a framework that helps them understand when all the events that they learn about in science, history and English (authors) took place relative to one another.

  36. David Cotton 3 years ago

    I really do like searching for stories to enrich my teaching. The mini one is a good one as it is so recent. Apparently it was a conductive paint that was wearing off too quickly.

    There are a lot of great news stories on the BBC news site for teaching science Mini static

    Static can build up on people when they return to their car (in american pump system) as the pump is filling the car. Then they can ignite vapours at the top of the fuel pipe.

    I love the way the person doesn’t run away but stays and tries to put the fire out.

  37. David Cotton 3 years ago

    Another issue with static build up from friction is with helicopters. In this video, “Femi investigates static” there is a great explanation of how the winch-person drops an earthing strap before touching ground or a person.

  38. David Cotton 3 years ago

    Here is a great real video of the static build up from the friction of the air and blade rotation on a helicopter

  39. Peter Tiktin 3 years ago

    A wonderful set of ideas – a great extension away from student’s hair standing on end.

    How about the old Nuffield experiments of a vdg connected to a set of parallel plates which can then cause

    1. a candle flame to broaden
    2. a conductive ping pong ball to bounce between the plates
  40. David Cotton 3 years ago

    Hi Peter, I really like adding things anew to the use of a good VdG
    When we teach capacitors in Y13  we use a bin bag capacitor

    I have never though of supplying the necessary potential difference between the plates with a VdG. It is half term so I should get the time to check it out.

    • David Ferguson 3 years ago

      Somewhat related, but for a different application, use of capacitors and VdGs discouraged by CLEAPSS.

      GL190 covers both VdG and Wimshurst machines.

  41. Dan Griffiths 3 years ago

    A little late to the party but so glad I came!

    Thanks for the demonstrations and all of the ideas and links – plenty to get my teeth in to! The fuel pipe problem hopefully makes the students see the immediate relevance of understanding static electricity.

    Thanks again

  42. Emma Dean 3 years ago

    I’m having trouble sourcing a really good VDG. Any recommendations? We do have one but can’t find a replacement belt anywhere. Currently using plastic tape (like to “police don’t cross” tape!!!)

  43. Robin Young 3 years ago

    How do I log in to the webinar?

  44. Robin Young 3 years ago

    oh now I see- it was Tuesday – next time – I’ll have a look at the resources and add anything that might be useful ..Thanks


  45. Thomas Chapman 3 years ago

    Thanks for the demos . I will have to have a go at the linear accelerator . As an alternative to graphite paint I have found that a 4B pencil provides a suitable covering for a table tennis ball .

  46. David Cotton 3 years ago


    Hi Peter we do the following with our high voltage supply usually

    and also the bin bag capacitor

    I tried this as you suggest with a VdG. I must add I have kept the plate size very small as we need to be careful not to build up too much charge. IMAG2179

    You can see how I use polystyrene to keep the whole capacitor and connections isolated. Also how I have connected one of the plates to the dome and the other plate to the earth connection. IMAG2182

    The yellow wire is my discharge wire as this must be done before dismantling the set up. You could improve this by having your discharge crocodile clip connected to a plastic ruler giving you plenty of distance.

    Here is a video, watch how the plates pull together

    I also recorded the spark as I discharge the capacitor

    Always be careful when making large capacitors and discharge them appropriately. Also pull them apart with a long wooden meter ruler or some plastic ruler.

  47. Kelly Mackay 3 years ago

    Some great ideas for using the VdG, we have used the pie trays before and a my little pony toy works really well similar to the bar or doll.   Just about to teach this section of P2 so perfect timing

  48. A Pirzada 3 years ago

    Gold leaf electroscope is my favourite for its cost effectiveness, size and portability.

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