Question

A reverse biased zener diode when operated in the breakdown region works as:

• A. an amplifier
• B. an oscillator
• C. a voltage regulator
• D. a rectifier

Hint:

Zener diodes are extensively used in power supplies to provide stable voltage regulation.

Answer 1

The Correct Option is C

Step 1: {Understanding Zener Diode} 
A zener diode allows current to flow in the reverse direction when the applied voltage exceeds the breakdown voltage. 
Step 2: {Function of a Zener Diode} 
In the breakdown region, the voltage across the diode remains nearly constant, making it ideal for voltage regulation. Thus, the correct answer is (C). 
 

Answer 2

Correct Answer:
Option 3 — a voltage regulator

Explanation:
A zener diode is designed to operate in the reverse breakdown region. When a reverse voltage applied across the zener diode reaches its breakdown voltage, it allows current to flow in the reverse direction while maintaining a nearly constant voltage across it. This property makes it ideal for use as a voltage regulator.

Key Point:
In the breakdown region, a zener diode maintains a steady output voltage despite changes in the input voltage or load conditions.

Thus, a reverse-biased zener diode in the breakdown region functions as a:
\[ \boxed{\text{Voltage Regulator}} \]