- "Electrostatics - Interaction of Charge", Video
21 - "Distribution of Charge on a Conductor",
Video 22 - "Induction of
Design and operation of an electroscope.
Nine basic experimental results:
cassette case picks up shredded paper, (b) charge an electroscope by
conduction and later by induction using various items - glass rod (+)
and silk (-), PVC (-) and fur (+), (c) a charged balloon (rubbed on
fur) "hangs" on a wooden door - and maybe other things, (d) a charged
rod is brought near a falling thin stream of water - and deflects it -
1. Electric charges
are of two kinds, positive and negative.
charges repel each other and unlike charges attract each other.
3. Substances differ in electrical conductivity:
(a) conductors - have many "free" electrons,
(b) insulators - have very few
free electrons, (c) semiconductors - have some free electrons.
4. The surplus charge on a solid or
hollow conductor resides entirely on its exterior
5. Electric charge concentrates at edges
and pointed surfaces on a conductor.
charges are separated by contact (rubbing things together), equal
amounts of positive and negative
charge are produced.
This is the Law of Conservation of Charge. (Charge can be
moved around but it cannot
be created or destroyed.)
7. Electric forces act at a distance.
A body can be charged by conduction or induction.
9. Higher humidity increases charge "leakage".