circuit devices

• Electrical circuit symbols


  Symbols that show the different components that can be found in an electrical circuit
• Common electrical circuit components

  • Switch
  • Lamp
  • Fixed resistor
  • Variable resistor
  • Thermistor
  • Light-dependent resistor (LDR)
  • Semiconductor diode
• Switch


  • Used to turn a circuit on (closed) and off (open)
• Lamp


  • Electrical current heats the filament, causing it to emit heat and light
• Fixed resistor


  • Resistance that is fixed and cannot be changed
• Variable resistor


  • Resistance can be changed by moving the position of the slider
• Thermistor


  • Resistance decreases as temperature increases
• Light-dependent resistor (LDR)


  • Resistance decreases as light intensity increases
• Semiconductor diode


  • Allows current to flow in one direction only
• Electrical current transfers energy around circuits
• Direct current


  Movement of charge through a conductor in one direction only
• Alternating current


  Electric current that regularly changes its direction and size