In an n-p-n transistor, the collector current is $28 \mathrm{~mA}$. If $80 \%$ of electrons reach the…
In an n-p-n transistor, the collector current is $28 \mathrm{~mA}$. If $80 \%$ of electrons reach the collector, its base current in $\mathrm{mA}$ is
- 35
- 24
- 14
- 7
Solution
It is given that $80 \% \mathrm{I}_{\mathrm{e}}=\mathrm{I}_{\mathrm{c}}=28 \mathrm{~mA}$
$\begin{aligned}
& \therefore \quad \frac{80}{100} \mathrm{I}_{\mathrm{e}}=28 \mathrm{~mA} \quad \Rightarrow \quad \mathrm{I}_{\mathrm{e}}=35 \mathrm{~mA} \\
& \text { But, } \mathrm{I}_e=\mathrm{I}_{\mathrm{c}}+\mathrm{I}_{\mathrm{B}} \\
& \therefore \quad \mathrm{I}_{\mathrm{B}}=\mathrm{I}_{\mathrm{e}}-\mathrm{I}_{\mathrm{c}} \quad \Rightarrow \quad \mathrm{I}_{\mathrm{B}}=35-28=7 \mathrm{~mA} \\
&
\end{aligned}$
^
Asked in: MHT CET 2023 (14 May Shift 2)
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