The number of terminals in `n-p-n` transistor is

Options

A. 2
B. 3
C. 4
D. 5

Answer

To determine the number of terminals in an NPN transistor, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of an NPN Transistor**:
- An NPN transistor consists of three layers of semiconductor material. The first layer is n-type (negative), the second layer is p-type (positive), and the third layer is again n-type (negative).

2. **Identify the Terminals**:
- Each transistor has three terminals:
- **Emitter (E)**: This is the terminal that emits charge carriers (electrons in the case of NPN).
- **Base (B)**: This is the terminal that controls the transistor's operation. It is the middle layer and is p-type.
- **Collector (C)**: This terminal collects the charge carriers from the emitter.

3. **Count the Terminals**:
- By identifying the three terminals (Emitter, Base, Collector), we can conclude that an NPN transistor has a total of three terminals.

4. **Conclusion**:
- Therefore, the number of terminals in an NPN transistor is **3**.

### Final Answer:
The number of terminals in an NPN transistor is **3**.

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