Physics - Semiconductors Question with Solution | TestHub

The current gain $\beta$ in a common emitter amplifier is given by:

$\beta =\frac{\Delta I_C}{\Delta I_B}$

Substituting the given values:

$\beta =\frac{5\text{ mA}}{0.2\text{ mA}}=25$

The voltage gain $A_v$ is related to the current gain, load resistance $R_L$, and input resistance $R_{in}$ by the formula:

$A_v=\beta \times \frac{R_L}{R_{in}}$

Substituting the known values into the equation:

$75=25\times \frac{R_L}{2\text{ k}\Omega }$

$\frac{R_L}{2\text{ k}\Omega }=\frac{75}{25}=3$

$R_L=3\times 2\text{ k}\Omega =6\text{ k}\Omega$

Answer: $6$ k$\Omega$