Question

For a CE-transistor amplifier, the audio signal voltage across the collector resistance of 2 k$\Omega$ is 2 V. Suppose the current amplification factor of the transistor is 100, find the input signal voltage and base current, if the base resistance is 1 k$\Omega$.

Answer 1

Given,Collector resistance,$R_C=2k\Omega$

Output voltage,$V_0=2V$

Base resistance,$R_B=1k\Omega$

Current amplification factor,$\beta =100$



For input signal voltage ,$V_{in}=I_B{R}_B$

$V_{in}=\frac{I_C{R}_B}{\beta }$

For base current,$I_B=\frac{I_C}{\beta }$

$I_B=\frac{V_C}{R_C\beta }$

$=\frac{2}{(2000\times 100)}$

$=10\mu A.$

Input signal voltage,
$V_{in}=I_B{R}_B$

$=10\times {10}^{-6}\times {10}^3$

=$10mV$