What is the most useful characteristic of a Zener diode?

  1. A constant current drop under conditions of varying voltage
  2. A constant voltage drop under conditions of varying current
  3. A negative resistance region
  4. An internal capacitance that varies with the applied voltage


What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

  1. Much higher reverse voltage breakdown
  2. More constant reverse avalanche voltage
  3. Longer carrier retention time
  4. Less forward voltage drop


What type of bias is required for an LED to emit light?

  1. Reverse bias
  2. Forward bias
  3. Zero bias
  4. Inductive bias


What type of semiconductor device is designed for use as a voltage-controlled capacitor?

  1. Varactor diode
  2. Tunnel diode
  3. Silicon-controlled rectifier
  4. Zener diode


What characteristic of a PIN diode makes it useful as an RF switch?

  1. Extremely high reverse breakdown voltage
  2. Ability to dissipate large amounts of power
  3. Reverse bias controls its forward voltage drop
  4. Low junction capacitance


Which of the following is a common use of a Schottky diode?

  1. As a rectifier in high current power supplies
  2. As a variable capacitance in an automatic frequency control circuit
  3. As a constant voltage reference in a power supply
  4. As a VHF/UHF mixer or detector


What is the failure mechanism when a junction diode fails due to excessive current?

  1. Excessive inverse voltage
  2. Excessive junction temperature
  3. Insufficient forward voltage
  4. Charge carrier depletion


Which of the following is a Schottky barrier diode?

  1. Metal-semiconductor junction
  2. Electrolytic rectifier
  3. PIN junction
  4. Thermionic emission diode


What is a common use for point-contact diodes?

  1. As a constant current source
  2. As a constant voltage source
  3. As an RF detector
  4. As a high-voltage rectifier


In Figure E6-2, what is the schematic symbol for a light-emitting diode?

  1. 1
  2. 5
  3. 6
  4. 7
Circuit Diagram


What is used to control the attenuation of RF signals by a PIN diode?

  1. Forward DC bias current
  2. A sub-harmonic pump signal
  3. Reverse voltage larger than the RF signal
  4. Capacitance of an RF coupling capacitor