An incomplete sentence about transistors is given below :The emitter-…..junction is_and the collector -….junction is _.The appropriate words for the dotted empty positions are, respectively

Options

A. collector'and 'base'
B. base'and 'emitter'
C. collector'and 'emitter'
D. base' and 'base'

Answer

To fill in the blanks in the sentence about transistors, we need to understand the functioning of a transistor, particularly in the context of how it operates as an amplifier.

### Step-by-Step Solution:

1. **Understanding the Transistor Structure**: A transistor typically has three regions: the emitter, the base, and the collector. The junctions formed between these regions are crucial for the operation of the transistor.

2. **Identifying the Emitter-Base Junction**: For a transistor to function properly, the emitter-base junction must be in a specific biasing condition. In the case of an NPN transistor (for example), the emitter is usually made of n-type material, and the base is made of p-type material.

3. **Biasing Conditions**:
- The **emitter-base junction** needs to be **forward-biased** for the transistor to allow current to flow from the emitter to the base. This means that the emitter is at a higher potential than the base.
- The **collector-base junction**, on the other hand, must be **reverse-biased**. This means that the collector is at a higher potential than the base, preventing current from flowing from the collector to the base.

4. **Filling in the Blanks**:
- The first blank (emitter-____ junction) should be filled with "base" because we are referring to the emitter-base junction.
- The second blank (collector-____ junction) should also be filled with "base" because we are referring to the collector-base junction.

5. **Final Sentence**: The completed sentence reads: "The emitter-base junction is **forward-biased** and the collector-base junction is **reverse-biased**."

### Answer:
The appropriate words for the dotted empty positions are, respectively: **base** and **base**.