Physics - Semiconductors Question with Solution | TestHub

The relation between the common base current gain $\alpha$ and the common emitter current gain $\beta$ is given by:

$\beta =\frac{\alpha }{1-\alpha }$

Substituting the given value of $\alpha =0.8$:

$\beta =\frac{0.8}{1-0.8}=\frac{0.8}{0.2}=4$

The change in collector current $\Delta I_C$ is related to the change in base current $\Delta I_B$ by:

$\Delta I_C=\beta \Delta I_B$

Given $\Delta I_B=3\mu \mathrm{A}$, we get:

$\Delta I_C=4\times 3\mu \mathrm{A}=12\mu \mathrm{A}$

Answer: $12\mu \mathrm{A}$