A transistor having $\alpha=0.8$ is connected in common emitter configuration. When the base current changes…
A transistor having $\alpha=0.8$ is connected in common emitter configuration. When
the base current changes by $6 \mathrm{~mA}$, the change in collector current is
$12 \mathrm{~mA}$
$1.5 \mathrm{~mA}$
$24 \mathrm{~mA}$
$0.66 \mathrm{~mA}$
Solution
A transistor having $\alpha=0.8$ is connected in common emitter configuration. When the base current changes by 6 mA , then the change in collector current is 24 mA .
Given, $\alpha=0.8$
Change In base current, $\Delta \mathrm{l}_{\mathrm{b}}=6 \mathrm{~mA}$
For common emitter configuration,
$\beta=\frac{\alpha}{1-\alpha}=\frac{0.8}{1-0.8}=4$
Also, $\beta=\frac{\Delta \mathrm{l}_{\mathrm{c}}}{\Delta \mathrm{l}_{\mathrm{b}}}$
$\begin{aligned}
& 4=\frac{\Delta \mathrm{l}_{\mathrm{c}}}{6 \mathrm{~mA}} \\
& \Delta \mathrm{l}_{\mathrm{c}}=24 \mathrm{~mA}
\end{aligned}$