PN junctions and diodes

Which phenomenon does a voltage-regulator (Zener) diode mainly use?

  1. AForward diffusion current
  2. BBreakdown under reverse bias
  3. CElectromotive force from absorbed light
Show answer and explanation

Answer: B. Breakdown under reverse bias

A voltage-regulator diode uses the fact that when the reverse voltage reaches a certain value (the breakdown voltage), current suddenly flows and the voltage stays nearly constant even as the current changes. Breakdown can be Zener breakdown or avalanche breakdown. Electromotive force from light is used in solar cells and photodiodes.

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More PN junctions and diodes questions

  1. Which correctly describes the relationship between forward current and forward voltage of a PN junction diode?
  2. What is the forward voltage (the approximate voltage at which current starts to flow) of a typical silicon PN junction diode?
  3. How does the reverse saturation current of a PN junction diode depend on temperature?
  4. Which is a characteristic of a Schottky barrier diode?
  5. Which property does a variable-capacitance (varactor) diode use?