# Electricity and Magnetism Essay

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ELECTRICITY AND MAGNETISM STATIC ELECTRICITY- (electrostatics) – is the study of electric charges at rest. A body is electrically charged when o It has more protons than electrons (positively charged). o It has more electrons than protons (negatively charged). Experiments show that: 1 like charges repel and unlike charges attract, and   The force between two charged bodies may be repulsive or attractive.  The symbol for electric charge is Q and the coulomb is the unit of electric charge and its symbol is C. 2 the force of attraction or repulsion decreases as the charges are moved further apart. A conductor is material which allows charges to flow through it easily.  An insulator is a material which does not allow charges to flow through it easily.  Bodies can be charged in three ways: o charging by friction o charging by induction. o charging by contact Electric fields An electric field is defined as: a region in which an electric charge will experience a force. o The field lines of force are directed away from a positive charge and towards a negative charge. o A single point charge has a radial field pattern.  The closeness of the field lines also gives an indication of the strength of the electric field at that point. o The diagrams below represent the fields for different arrangements of point charges and between charged parallel plates. Electric field for a single positive charge Electric field for a single negative charge Electric field for two opposite charges(attraction) Electric field for two like charges (repulsion)  The potential, V, at a point in the field is the work done in bringing a unit positive charge (+1C) from outside the field to that point in the field. CHARGING BY FRICTION An object becomes charged by adding electrons, negative () charges, to it or by taking away electrons from it. This is usually done by