A 40 × 40 mm zinc plate, from Lascells, mounted on a 4mm plug connector, which can be used in place of the top plate of a suitable electroscope (one where the top plate can be removed and has a 4mm connector). The zinc plate can then be used to demonstrate the photo-electric effect, where discharge of electrons from a charged gold leaf can be observed using short wave UV Light (UV-C) shone directly onto the plate.
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