Home > Educational Material > Learning Resources > Physics - Static Electricity

Physics - Static Electricity

Electricity is the phenomenon caused by the presence or movement of charges which exert an electric force. A material is said to have a negative electric charge if it has a surplus of electrons, and a positive electric charge if it has a deficit of electrons. An electric current is the movement of a charge through materials. This can be contrasted with static electricity, which can be said to be electricity "held" by a material with electric charge.

First law of electrostatics

Changes that are alike repel each other and charges that are unlike attract each other. A charged particle always attracts an uncharged conductor by induction.

Conductor

Amaterial containing a large number of charges which are free to move. It can therefore conduct electricity. Metals, e.g. copper, aluminium and gold, are good conductors because they contain large numbers of electrons which are free to move.

Insulator

A material with very few or no charges free to move. Some insulators become electrically charged when rubbed. This is because electrons from the surface atoms are transferred from one substance to the next, but the charge remains on the surface.

Electroscope

An instrument for detecting small amounts of electric charge. A gold leaf electroscope is the most common type. When the leaf and rod become charged, they repel and the leaf diverges from the rod. The greater the charges, the larger the divergence of the leaf. A condensing electroscope contains a capacitor between the cap and the case which increases the sensitivity.

Lightning

The sudden flow of electricity from a cloud which has become charged due to the rubbing together of different particles, e.g. water droplets. A lightning conductor is used to help cancel the charge on the cloud by point action and to conduct the electricity down to Earth so that it does not flow through buildings.

Word Document

Educational Material

Rss Feed Available RSS Our Blog Feed

Get Adobe Reader Adobe .PDF

 

Help us keep it free by donating.

LiveBinder It