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Question: Answered & Verified by Expert
In the study of transistor as an amplifier, if $\alpha=I_c / I_e$ and $\beta=I_c / I_b$, where $I_c, I_b$ and $I_c$ are the collector, base and emitter currents, then
PhysicsSemiconductorsJEE Main
Options:
  • A $\beta=\frac{1-\alpha}{\alpha}$
  • B $\beta=\frac{\alpha}{1-\alpha}$
  • C $\beta=\frac{\alpha}{1+\alpha}$
  • D $\beta=\frac{1+\alpha}{\alpha}$
Solution:
1076 Upvotes Verified Answer
The correct answer is: $\beta=\frac{\alpha}{1-\alpha}$
As we know $i_E=i_C+i_B$
$\Rightarrow \frac{i_e}{i_c}=1+\frac{i_b}{i_c} \Rightarrow \frac{1}{\alpha}=1+\frac{1}{\beta} \Rightarrow \beta=\frac{\alpha}{1-\alpha}$

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