Electricity and Magnetism > Electrostatics DCS# 5A10.10
CHARGING BY CONTACT
charging by contact
APPARATUS
rabbit fur 202-18-D4
silk 202-18-D3
wool 202-18-D3
hard rubber rod 202-18-D6
glass rod 202-18-D6
plexiglas rod 202-18-D6
electroscope 202-18-C
pith balls 202-18-C
hanging glass rod 202-18-D6

DESCRIPTION
Rub together two different insulators to give them opposite charges.  Demonstrate their effects on an electroscope or pair of pith balls.

 
NOTES
 
Pairs of materials that have been found to work well:
rabbit fur(+) and rubber rod(-)
wool(+) and rubber rod(-)
rabbit fur(+) and styrofoam block(-)
silk(-) and glass rod(+)
acrylic or nylon rod and plastic bag

Other possibilities:
positive
rabbit fur
glass
mica
wool
silk
cotton
styrofoam
wood
amber
rubber
celluloid
negative

Things used to demonstrate presence and sign of charge:
conventional electroscope
pair of hanging balloons
pair of hanging plastic bottles
pair of hanging pith balls
suspended glass rod which is free to rotate

Nylon thread and fishing line are good insulators for suspending charged things.