Figure shown below shows a common emitter amplifier. The quiescent collector voltage of the circuit is approximately.

With the ideal operational amplifiers, the circuit in figure simulates the equation

In the figure shown, assume that the zener diode and operational amplifier to be ideal.

$$(a)$$ Draw the equivalent circuit and evaluate the gain $$\left( {{V_0}\,\,vs\,\,{V_i}} \right)$$ of the circuit for

$$(i)$$ $${V_i} \le 0$$ $$\,\,\,\,\,\left( {ii} \right)\,\,\,0 < {V_i} < 5V\,\,\,\,\,\,$$ $$\,\,\,\,\,\left( {iii} \right)\,\,\,{V_i} > 5V\,\,\,\,\,\,$$

$$(b)$$ Sketch the gain $$\left( {{V_0}\,\,\,{V_s}\,\,\,{V_i}} \right)$$ characteristics of the above circuit and label the salient features.

Figure shows a common emitter amplifier

$$(a)$$ Simplify the circuit by applying thevenin's theorem to biasing network $${R_1},{R_2}$$ at
$$\,\,\,\,\,\,\,$$ the base of the transistor.
$$(b)$$ Assuming $${C_s}$$ to be a short for frequency range considered. Draw the small signal
$$\,\,\,\,\,\,\,$$ $$a.c.$$ model of the circuit obtained in $$(a)$$ by using the simple model for the
$$\,\,\,\,\,\,\,$$ transistor shown in figure.
$$(c)$$ Evaluate the small signal gain $$\left( {{{{V_0}} \over {{V_i}}}} \right)$$ of the amplifier.