Question

A transistor has a current amplification factor (current gain) of $50$. In a common emitter amplifier circuit, the collector resistance is chosen as $5$$\Omega$ and the input resistance is $1$$\Omega$ . The output voltage if input voltage is $0.01$ $V$ is

• A. $-5v$
• B. $-2v$
• C. $-1v$
• D. $2.5v$

Answer 1

The correct option is D $2.5v$

The current amplification factor $\beta =\frac{i_c}{i_b}=\frac{output}{input}$

$\beta =\frac{i_c}{i_b}=\frac{\left(\frac{V_{out}}{R_{out}}\right)}{\left(\frac{V_{in}}{R_{out}}\right)}$

$50=\frac{\left(\frac{V_{out}}{5}\right)}{\left(\frac{0.01}{1}\right)}$

$V_{out}=2.5\text{Volt}$