Zener diode acts as a/an

Options

A. oscillator
B. regulator
C. rectifier
D. filter

Explanation

To answer the question "Zener diode acts as a/an", we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding the Zener Diode**:
- A Zener diode is a special type of semiconductor diode that allows current to flow in the reverse direction when a specific reverse voltage, known as the breakdown voltage, is reached.

2. **Reverse Bias Condition**:
- Unlike regular diodes that only conduct in the forward bias condition, Zener diodes are designed to operate in reverse bias. This means they can withstand high reverse voltages without getting damaged.

3. **Voltage-Current Characteristics**:
- In the reverse bias region, the Zener diode exhibits a unique voltage-current characteristic. Initially, a small amount of current flows through the diode, but once the reverse voltage reaches the breakdown voltage, the current increases sharply while the voltage remains relatively constant.

4. **Breakdown Voltage**:
- The breakdown voltage is a critical point for Zener diodes. Beyond this voltage, the diode can regulate the voltage effectively by maintaining a constant output voltage despite changes in the load current.

5. **Application as a Voltage Regulator**:
- Due to its ability to maintain a constant voltage across it when in breakdown, the Zener diode is commonly used as a voltage regulator in electronic circuits. This means it can control and stabilize the voltage to a desired level.

6. **Conclusion**:
- Therefore, the Zener diode acts as a voltage regulator.

### Final Answer:
Zener diode acts as a **voltage regulator**.

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