In a normal operation of a transistor,

Options

A. the base-emitter junction is forward-biased
B. the base-collector junction is forward-biased
C. the base-emitter juncion is reverse-baised
D. the base-coolector junction is reverse-baised

Answer

To solve the question about the normal operation of a transistor, we will analyze the configuration of an NPN transistor and the biasing conditions required for its proper functioning.

### Step-by-Step Solution:

1. **Identify the Transistor Configuration**:
- We are dealing with an NPN transistor, which consists of three regions: the emitter (E), the base (B), and the collector (C).

2. **Understand the Biasing Conditions**:
- In a normal operation of an NPN transistor, there are two junctions to consider:
- The base-emitter junction (BE junction)
- The base-collector junction (BC junction)

3. **Base-Emitter Junction**:
- For the transistor to operate in the active region, the base-emitter junction must be **forward biased**. This means that the base must be at a higher potential than the emitter, allowing current to flow from the emitter to the base.

4. **Base-Collector Junction**:
- Conversely, the base-collector junction must be **reverse biased**. This means that the collector must be at a higher potential than the base, preventing current from flowing from the base to the collector under normal operation.

5. **Conclusion**:
- Therefore, in the normal operation of an NPN transistor:
- The base-emitter junction is forward biased.
- The base-collector junction is reverse biased.
- This configuration allows the transistor to amplify signals or switch currents effectively.

### Final Answer:
In a normal operation of a transistor (specifically an NPN transistor), the base-emitter junction is forward biased, and the base-collector junction is reverse biased.