Diodes and LED's

• What should you be able to describe by the end of the video?

  The shape of the current potential difference graph for a diode
• What is a light emitting diode (LED)?

  A diode that emits light when current flows
• Why are diodes useful in circuits?

  They control the flow of current
• How does current behave in a resistor?

  It is directly proportional to potential difference
• What happens to the current in a filament lamp as it heats up?

  The resistance increases, affecting current flow
• What is the key feature of a diode?

  Current flows in one direction only
• What does the arrow in the diode symbol indicate?

  The direction of conventional current flow
• How does a diode behave when the current flows in the reverse direction?

  No current can flow due to high resistance
• What does the current potential difference graph for a diode show?

  No current in reverse direction, increases in forward direction
• Where can you commonly find LEDs?

  In cameras, light bulbs, and televisions
• How does an LED differ from a normal diode?

  It emits light when current flows through
• Why are LEDs considered energy efficient?

  They produce light with less energy consumption
• What should you remember about questions on diodes and LEDs?

  They will appear in the vision workbook
• What are the characteristics of a diode and an LED?

  • Diode:
  • Allows current in one direction
  • High resistance in reverse direction
  • LED:
  • Emits light when current flows
  • Energy efficient source of light
• What are the differences in current flow between a resistor, filament lamp, diode, and LED?

  • Resistor: Current directly proportional to potential difference
  • Filament lamp: Current not directly proportional due to heating
  • Diode: Current flows only in one direction
  • LED: Current flows in one direction and emits light