PN junctions and diodes

What happens to the width of the depletion layer when the reverse bias applied to a PN junction is increased?

  1. AIt narrows
  2. BIt does not change
  3. CIt widens
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Answer: C. It widens

Under reverse bias, the external voltage adds to the built-in potential and pulls carriers further away from the junction, so the depletion layer widens. As it widens, the junction capacitance decreases, a property used in variable-capacitance (varactor) diodes.

Depletion layer of a PN junction under reverse bias Electron Hole No bias −,+,−,+ ,,, ,,,, p-type n-type Depletion layer Larger reverse bias −,+,−,+,−,+,−,+,−,+,−,+ ,, ,,, p-type n-type Depletion layer widens
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  1. Which phenomenon does a voltage-regulator (Zener) diode mainly use?
  2. Which correctly describes the relationship between forward current and forward voltage of a PN junction diode?
  3. What is the forward voltage (the approximate voltage at which current starts to flow) of a typical silicon PN junction diode?
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  5. Which is a characteristic of a Schottky barrier diode?