First 271 words of the document:
Physics Static electricity
Static electricity is charge `held' by an insulator or insulated conductor. It is
produced when two surfaces rub together.
Adding electron to an atom makes it negative
Taking electrons away from atom makes it positive.
Charging by friction:
Some insulators become charged by rubbing them with a cloth.
Rubbing a polythene rod with a dry cloth transfers electrons from the
cloth to the polythene rod. This means the rod becomes negatively
Rubbing a Perspex cloth with a dry cloth transfers electrons from the
Perspex rod to the cloth. This means the cloth becomes positively
The Van de Graaff Generator:
The belt rubs against the felt pad and becomes charged
The belt carries the charge on to the dome.
Sparks are produced, when the dome can do longer hold
any more charge.
The discharger provides a route for excess charge to be
The rate of flow of electrical charge is called Current
Charging a conductor:
A conductor can only hold charge if it is insulated from the ground. If
it isn't, then the electron will be earthed.
To charge a conductor it must be brought in contact with a charged
If the object is positively charged, electrons transfer from the conductor
to object so the conductor become positive.
If the object is negatively charged, electrons transfer from the object to
the conductor so conductor becomes negative.
Uses of Static Electricity: