physics

• Electric charge


  Property that causes matter to experience a force when placed in an electromagnetic field
• Law of Conservation of Electric Charge


  • When two different bodies are rubbed against each other, the electrons are simply transferred from one body to another
  • No electron is destroyed nor created during the process
  • Mathematically, the sum of the positive and negative charges during the process of rubbing is zero
• Charging


  Process of supplying the electric charge to an object or losing an electric charge from an object
• Conductors


  • Allows charges to flow readily
• Insulators


  • Resists the flow of charges
• Semiconductor


  • Intermediate between a conductor and an insulator (e.g. silicon, germanium & gallium arsenide)
• Superconductor


  • Offers practically no resistance to flow of charges below some critical temperatures (e.g. combination of Yttrium, Barium, Copper and Oxygen)
• Charging by Friction


  Triboelectric series - materials above are positively charged and materials below are negatively charged
• Charging by Conduction


  1. Contact between the neutral body and the charging body

  2. The sign of the charge produced is the same as that of the charging body
• Charging by Induction


  1. Does not involve contact between the neutral body and the charging body

  2. Unlike charges
• Coulomb's Law


  Formulated by Charles De Agustine Coulomb
• Superposition Principle


  Total electric force a particular charge experiences is due to vector sum of all individual forces
• Electric Field, E


  Any region in space where a positive (+) test charge placed at any point within the region experienced a force which is electric in nature
• Electric Field Lines


  Imaginary lines drawn in such a way that their direction at any point is the same as the direction of the field at that point
• Field Lines start on positive charges.
• Field Lines stop on negative charges.
• More charge = more field lines
• Field Lines spacing indicates its strength. The closer the space the stronger.