Question

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

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

Answer 1

The correct option is C $1.0V$

Voltage gain$=\frac{\text{Output voltage}}{\text{Input voltage}}$

$\Rightarrow V_{out}=V_{in}\times voltagegain$
$\Rightarrow V_{out}=V_{in}\times \Delta I\times R$
where $\Delta I$ is the current gain and R is the resistance gain
$\Rightarrow V_{out}=V_{in}\times b\times \frac{R_L}{R_{BE}}$

$\Rightarrow V_{out}={10}^{-3}\times 100\times \frac{10}{1}$
$=1V$