When two bodies are rubbed together, they acquire the property of attracting light objects like small bits of paper, dust particles etc. The bodies which acquire this property are said to be electrified or charged with electricity.
Charge is the basic property associated with matter due to which it produces and experiences electrical and magnetic effects
» Benjamin Frankline named the two types of charges as positive and negative.
» Similar charges repel each other and opposite charges attract each other.
» Charging of bodies takes each other place due to transfer of electrons from one body to other bodies.
Surface density of charge is defined as the amount of charge per unit area on the surface of conductor.
» The surface density of charge at a point on the surface of conductor depends upon the shape of conductor and presence of other conductors or insulators near the given conductor.
» The surface density of charge at any part of the conductor is inversely proportional to the radius of curvature of the surface of that part.
» This is why surface density of charge in maximum at the pointed parts of the conductor.
Conductors are those materials which allow electricity (charge) to pass through themselves. Good conductor have loosely bound electrons.
» Silver is the best conductor.
Insulators are those materials which do not allow electricity to flow through themselves.