This apparatus enables electric field patterns to be shown in much the same way that magnetic fields are demonstrated with iron filings, either by direct viewing or on an overhead projector.
The apparatus comprises of a clear plastic petridish on an acrylic base, which carries a pair of 4mm socket terminals/electrode holders.
Alongside each terminal is a thumbscrew system which permits fine height adjustment of the electrodes.
Six electrodes in different shapes, are supplied, two 'point source' two 'line source' and two circular rings of 35 and 70 mm diameter.
Fill the dish with oil and mount your choice of electrodes just beneath the surface. Sprinkle iron filings and connect to show the patterns created.