Diodes

• What is a diode?

  A diode is a component that allows current to flow in one direction only.
• What is another name for a diode?

  They are also referred to as semiconductor diodes.
• What visual indicator is often found on a diode to show its direction?

  A gray stripe is usually present to indicate the direction.
• How can you recognize a diode's circuit symbol?

  The symbol consists of a triangle and a line drawn in a circle.
• What does the triangle in the diode symbol indicate?

  The triangle indicates the direction of the diode.
• What is referred to as the positive bias of the diode?

  The direction in which current can flow normally through the diode.
• What happens when the current is reversed in a diode?

  The diode stops the current from flowing.
• In which direction does conventional current flow in a circuit?

  From the positive end of the cell to the negative end.
• In a circuit where the current flows anticlockwise, what does the diode's direction indicate?

  If the triangle points in the same direction as the current, the diode does not affect it.
• What is the role of a diode in complex circuits?

  Diodes prevent currents from flowing back on themselves.
• What is the threshold potential difference for a diode?

  It is the minimum potential difference required for the diode to conduct current.
• What is the typical threshold potential difference for a diode?

  About 0.7 volts.
• How does the IV graph of a diode behave above the threshold potential difference?

  The graph shows positive values for current and a steep slope, indicating low resistance.
• What does a steep slope on the IV graph indicate about a diode's resistance?

  A steep slope indicates that the diode has low resistance.
• What happens to the diode's resistance below the threshold potential difference?

  The resistance becomes extremely high, stopping current flow.
• What does the horizontal part of the IV graph indicate for a diode?

  It indicates that there is no current flowing through the diode.
• How does a light-emitting diode (LED) function?

  An LED lights up when current flows through it in the correct direction.
• What is the common color of light emitted by LEDs?

  They are most commonly red but can be made in various colors.
• How can you determine the positive bias of an LED?

  The longer leg indicates the positive bias, while the shorter leg indicates the negative bias.
• What is the circuit symbol for an LED?

  It is the same as a normal diode but with arrows to show emitted light.
• How does the IV graph of an LED compare to that of a standard diode?

  The IV graph for an LED is the same as that of a standard diode.
• What does the steep part of the IV graph for an LED indicate?

  It indicates low resistance to allow current flow.
• What does the horizontal part of the IV graph for an LED indicate?

  It indicates high resistance to stop current flowing in the wrong direction.
• What are the key characteristics of diodes and LEDs?

  • Diodes allow current to flow in one direction.
  • Diodes have a gray stripe indicating direction.
  • The circuit symbol consists of a triangle and a line.
  • LEDs light up when current flows in the correct direction.
  • LEDs have no stripe but use leg length to indicate direction.
• What is the significance of the IV graph for diodes and LEDs?

  • Shows relationship between current and potential difference.
  • Above threshold potential difference: low resistance, current flows.
  • Below threshold potential difference: high resistance, no current flows.
• What are the applications of diodes and LEDs in circuits?

  • Diodes prevent reverse current flow in complex circuits.
  • LEDs indicate current flow visually in circuits.