Q151 / 180 · COMEDK 2014 · Physics
In a common base circuit, collector base voltage changes by $0.6 \mathrm{~V}$ and collector current changes by $0.02 \mathrm{~mA}$. Then, the output resistance is
- A$6 \times 10^{4} \Omega$
- Correct answerB$3 \times 10^{4} \Omega$
- C$9 \times 10^{4} \Omega$
- D$18 \times 10^{4} \Omega$
Solution
In common base circuit, change in collector base voltage,
$$
\begin{aligned}
&V_{C B}=0.6 \mathrm{~V} \\
&\Delta I_{C}=0.02 \mathrm{~mA}=2 \times 10^{-5} \mathrm{~A}
\end{aligned}
$$
$\therefore$ Output resistance,
$$
R_{\mathrm{out}}=\frac{\Delta V_{C B}}{\Delta I_{C}}=\frac{0.6}{2 \times 10^{-5}}=3 \times 10^{4} \Omega
$$
Hence, the correct answer is option: 'B'.