Regarding transistor what is not correct.

Options

A. For transistor to act as an amplifier, EB junction should be forward biased and CB junction should be reverse biased
B. `l_(E)=l_(B)+l_(C )` in any configuration and for any transistor
C. `alpha=(beta)/(1+beta)` where `alpha ` and `beta` are transistor parameters
D. `beta=(alpha)/(1+alpha)`

Answer

To determine which statement regarding transistors is not correct, we will evaluate each of the provided options step by step.

### Step-by-Step Solution:

1. **Evaluate Option 1**:
- The statement is: "For a transistor to act as an amplifier, the emitter-base junction should be forward biased and the collector-base junction should be reverse biased."
- **Analysis**: This is correct. For a transistor (in common emitter configuration) to function as an amplifier, the emitter-base junction must be forward biased, allowing current to flow from the emitter to the base, while the collector-base junction must be reverse biased to allow for proper operation and amplification.
- **Conclusion**: Option 1 is true.

2. **Evaluate Option 2**:
- The statement is: "IE = IB + IC is a configuration of any transistor."
- **Analysis**: This is also correct. The relationship states that the emitter current (IE) is equal to the sum of the base current (IB) and the collector current (IC). This is a fundamental principle of transistor operation.
- **Conclusion**: Option 2 is true.

3. **Evaluate Option 3**:
- The statement is: "α = β / (1 + α / (1 + β))".
- **Analysis**: This statement is indeed true as it represents a relationship between the current gain factors of a transistor (α and β). However, it is a bit convoluted and not the most common expression used.
- **Conclusion**: Option 3 is true.

4. **Evaluate Option 4**:
- The statement is: "β = α / (1 + α)".
- **Analysis**: This statement is incorrect. The correct relationship between β (current gain in common emitter configuration) and α (current gain in common base configuration) is: β = α / (1 - α). The given expression does not hold true.
- **Conclusion**: Option 4 is not correct.

### Final Answer:
The option that is not correct regarding transistors is **Option 4**.

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