Glossary

• diode

  a non-ohmic conductor that has a much higher resistance in one direction (its reverse direction) than in the other

  direction (its forward direction).
• Electric field

  a charged object (X) creates an electric field around itself, which causes a non-contact force on any other charged

  object in the field
• Electrons

  tiny negatively charged particles that move around the nucleus of an atom.
• Ion 


  a charged atom or molecule.
• Light-depending resistor (LDR)


  a resistor whose resistance depends on the intensity of light incident on it.
• light-emitting diode (LED)


  diode that emits light when it conducts.
• line of force in an electric field 


  line along which a free positive charge moves long in an electric field.
• neutrons

  uncharged particles of the same mass as protons. The nucleus of an atom consists of protons and neutrons.
• Ohm's law

  the current through a resistor at constant temperature is directly proportional to the potential difference across the resistor.