electricity

• electricity is the study of the flow of electric charge and the forces that act on it.
• electric current is the amount of charge flowing through a particular area in a unit time.

  The SI unit is Ampere (A).
• charge is a characteristic of a unit of matter that expresses the extent to which it has more or fewer electrons than protons.
• a switch makes a conducting link between the cell and the bulb.
• an electric circuit is a continuous and closed path of an electric current.
• properties of charges:

  1. like charges repel, unlike charges attract
  2. charges are quantized.
  3. charge of electron 1.6 × 10-19
• One ampere is constituted by the flow of one coulomb of charge per second.
• An ammeter is an instrument that measures electric current in a circuit.