Physics - Semiconductors Question with Solution | TestHub

Given:
Input resistance, $R_{in}=1.8\text{ k}\Omega$
Output resistance, $R_{out}=9\text{ k}\Omega$
Current gain, $\beta =70$
Input voltage, $V_{in}=6\text{ mV}$

The voltage gain $A_v$ of a common emitter amplifier is given by:
$A_v=\beta \times \frac{R_{out}}{R_{in}}$

Substituting the given values:
$A_v=70\times \frac{9}{1.8}=70\times 5=350$

The output voltage $V_{out}$ is:
$V_{out}=A_v\times V_{in}$

$V_{out}=350\times 6\text{ mV}=2100\text{ mV}=2.1\text{ V}$

Answer: 2.1 V