Electrostatics experiments

Light objets attraction Hanging balloon Trickle of water Electroscope and versorium Charging and discharging by contact Charging by induction Points power Two sorts of electric charges (a) Two sorts of electric charges (b) Conduction Sign of Charges Electrostatic chime Electrophorus Faraday Cage
French page

by Michel Maussion - University of Nantes - France

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Electrophorus





Preparation

électrophorus1

   

Take the cap of one of the tubes you have used to make your supports. Cover it with aluminium outside and inside.

Find a metallic disc, which diameter is smaller than the cap, and stick a plastic rod in the middle.


électrophorus2

   

Cut out a piece of extruded polystyrene in the form of a parallelepiped. Its biggest area must be larger than the disk.

Pierce it in the middle by a copper wire bent at a square angle so it overstep the thickness 2 mm.

Material is ready.




Charging the electrophorus




Take the piece of polystyrene between your thumb and your third finger and rub with cotton or wool, the face around copper that overruns. Be careful not to touch this area in the following.


électrophorus3

   

 électrophorus4
Put your index finger on the thread backside
to ground it. Take the disc by the stick with
the other handand make contact.

   

 Verify that the disc is loaded.

     



Transfer of charges from the disc to the electroscope




   

Place the cylinder over the plate.

Introduce the disc into the cylinder, without touching the lateral side.

Put it in contact to the bottom.

Pull out the disc.


Do not lay down the insulator block. You can begin to charge the electrophorus again and discharge it at the bottom of the cylinder. Leaves part a bit more at each time.