Operation of a Zener Diode: Which of the following statements correctly describes the behavior of a Zener diode?

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:

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