Search any question & find its solution
Question:
Answered & Verified by Expert
In a CE transistor amplifier, the audio signal voltage across the collector resistance of $2 \mathrm{k} \Omega$ is $2 \mathrm{~V}$. If the base resistance is $1 \mathrm{k} \Omega$ and the current amplification of the transistor is 100 , the input signal voltage is
Options:
Solution:
2905 Upvotes
Verified Answer
The correct answer is:
$10 \mathrm{mV}$
Current amplification factor
$\beta=\frac{\Delta I_C}{\Delta I_B}$
Collector resistance
$\Delta I_C=\frac{2 \mathrm{~V}}{2 \times 10^3 \Omega}=1 \times 10^{-3} \mathrm{~A}$
Base current
$\Delta I_B=\frac{V_B}{R_B}=\frac{V_B}{1 \times 10^3}=V_B \times 10^{-3}$
Given, $\beta=100$
Now, $100=\frac{10^{-3}}{V_B \times 10^{-3}}$
$V_B=\frac{1}{100} \mathrm{~V}=10 \mathrm{mV}$
$\beta=\frac{\Delta I_C}{\Delta I_B}$
Collector resistance
$\Delta I_C=\frac{2 \mathrm{~V}}{2 \times 10^3 \Omega}=1 \times 10^{-3} \mathrm{~A}$
Base current
$\Delta I_B=\frac{V_B}{R_B}=\frac{V_B}{1 \times 10^3}=V_B \times 10^{-3}$
Given, $\beta=100$
Now, $100=\frac{10^{-3}}{V_B \times 10^{-3}}$
$V_B=\frac{1}{100} \mathrm{~V}=10 \mathrm{mV}$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.