Operation of a Zener Diode: Which of the following statements correctly describes the behavior of a Zener diode?
Electronics and Communication Engineering
Electronic Devices and Circuits
Difficulty: Easy
Choose an option
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Athe forward current is very high
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Bsharp breakdown occurs at a certain reverse voltage
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Cthe ratio v-i can be negative
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Dthere are two p-n junctions
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Eit has nearly zero recovery time
Answer
Correct Answer: sharp breakdown occurs at a certain reverse voltage
Explanation
Introduction / Context:Zener diodes are widely used as voltage regulators because of their controlled breakdown property. Understanding their correct defining behavior avoids confusion with other diode types.
Given Data / Assumptions:
- Device: Zener diode.
- Focus: reverse bias behavior.
Concept / Approach:
When reverse-biased to its Zener voltage (Vz), the diode undergoes controlled breakdown with nearly constant voltage, enabling regulation.
Step-by-Step Solution:
Step 1: Apply reverse bias.Step 2: At Vz, breakdown occurs sharply.Step 3: Current increases rapidly while voltage remains constant.Verification / Alternative check:
Practical voltage regulators confirm this controlled breakdown behavior.
Why Other Options Are Wrong:
- Forward current high: applies to all diodes, not unique.
- Ratio v-i negative: not true physically.
- Two p-n junctions: describes transistor, not diode.
Common Pitfalls:
- Confusing Zener with Schottky (fast recovery).
Final Answer:
sharp breakdown occurs at a certain reverse voltage