Question

In a common emitter configuration with suitable bias, it is given than $R_L$ is the load resistance and $R_{BE}$ is small signal dynamic resistance (input side). Then, voltage gain, current gain and power gain are given, respectively, by:
$\beta$ is current gain, $I_B,I_C,I_E$ are respectively base, collector and emitter currents:

• A. $\beta \frac{R_L}{R_{BE}},\frac{\Delta I_E}{\Delta I_B},{\beta }^2\frac{R_L}{R_{BE}}$
• B. ${\beta }^2\frac{R_L}{R_{BE}},\frac{\Delta I_C}{\Delta I_B},\beta \frac{R_L}{R_{BE}}$
• C. ${\beta }^2\frac{R_L}{R_{BE}},\frac{\Delta I_C}{\Delta I_E},{\beta }^2\frac{R_L}{R_{BE}}$
• D. $\beta \frac{R_L}{R_{BE}},\frac{\Delta I_C}{\Delta I_B},{\beta }^2\frac{R_L}{R_{BE}}$

Answer 1

The correct option is D $\beta \frac{R_L}{R_{BE}},\frac{\Delta I_C}{\Delta I_B},{\beta }^2\frac{R_L}{R_{BE}}$

Voltage gain = $\frac{V_{CE}}{V_{BE}}=\beta \frac{R_L}{R_{BE}}$

Current gain = $\beta =\frac{I_C}{I_B}$

Power gain = $voltagegain\times currentgain={\beta }^2\frac{R_L}{R_{BE}}$