Question

In the following common emitter configuration, an $NPN$ transistor with current gain $\beta =100$ is used. The output voltage of the amplifier will be

• A. 10 mV
• B. 0.1 V
• C. 1.0 V
• D. 10 V

Answer 1

Answer: (C)

Voltage gain $=\frac{\text{ Output voltage }}{\text{ Input voltage }}$
$\Rightarrow V_{\text{out }}=V_{\text{in }}\times$ Voltage gain
$\Rightarrow V_{\text{out }}=V_{\text{in }}\times$ Current gain $\times$ Resistance gain
$\Rightarrow V_{\text{out }}=V_{\text{in }}\times \beta \times \frac{R_L}{R_{BE}}$
$=10^{-3}\times 100\times \frac{10}{1}$
$=1V$