What is active region for transistor?

Answer

### Step-by-Step Solution

1. **Understanding Transistor States**:
A transistor operates in three distinct states: Cut-off, Saturation, and Active. Each state has specific characteristics that define how the transistor behaves.

2. **Defining the Active Region**:
The Active Region of a transistor is defined as the region between the Cut-off and Saturation states. It is the operational state where the transistor can amplify signals.

3. **Characteristics of the Active Region**:
- In the Active Region, the Base-Emitter junction is forward biased. This means that the current can flow from the base to the emitter, allowing the transistor to function.
- Simultaneously, the Collector-Base junction is reverse biased. This ensures that the transistor can control the flow of current from the collector to the emitter.

4. **Functionality in the Active Region**:
In this region, the transistor can amplify signals because it can control a larger collector current with a smaller base current. The transistor operates normally, allowing it to be used in various applications such as amplifiers and switches.

5. **Conclusion**:
The Active Region is crucial for the normal operation of the transistor, enabling it to perform its function of signal amplification effectively.