The given figure shows $2$-stage amplifier. The transistors $\mathrm{Q}_{1}$ and $\mathrm{Q}_{2}$ are identical with current gain $\beta=100$; further $\beta_{\text {dc }}=\beta_{a c}=\beta$. The zener diode $D_{z}$ has a break-down voltage $\mathrm{V}_{\mathrm{z}}=10.7$ volt. Assume that $D_{z}$ is in break-down region and its dynamic resistance $r_{z}$ is zero. The capacitors $C_{1}$ and $C_{2}$ are large and provide negligible impedance at signal frequencies.
- Identify the configuration in each of the amplifier stages (i.e. whether $\mathrm{CE}, \mathrm{CC}, \mathrm{CB}$ etc.)
- Determine the quiescent quantities $\mathrm{I}_{\mathrm{Cl}}$ and $\mathrm{V}_{\mathrm{Cl}}$.
- Derive an expression for the voltage gain $\text{A}_{\text{V}}$ $\Delta \frac{v_{0}}{v_{s}}$ and determine its value.
(Assume $\mathrm{V}_{\mathrm{BE}}=0.7 \mathrm{~V}, r_{0}=\infty$ and Thermal voltage $\text{V}_{\text{T}}=25 \mathrm{mV}$ )