Consider the common emitter amplifier shown below with the following circuit parameters:

$$\beta = 100,\,{g_m} = 0.3861\,{\rm A}/V,\,{r_0} = \infty ,\,{r_\pi } = 259\,\Omega, $$
$${R_s} = 1\,K\Omega ,{R_B} = 93\,K\Omega ,\,{R_C} = 250\,\Omega, $$
$${R_L} = 1\,K\Omega ,\,{C_1} = \infty \,\,and\,\,{C_2} = 4.7\,\mu F.$$

The Resistance seen by the source Vs is

Consider the common emitter amplifier shown below with the following circuit parameters:

$$\beta = 100,\,{g_m} = 0.3861\,{\rm A}/V,\,{r_0} = \infty ,\,{r_\pi } = 259\,\Omega, $$
$${R_s} = 1\,K\Omega ,{R_B} = 93\,K\Omega ,\,{R_C} = 250\,\Omega, $$
$${R_L} = 1\,K\Omega ,\,{C_1} = \infty \,\,and\,\,{C_2} = 4.7\,\mu F.$$

The lower cut-off frequency due to C₂ is

The transfer characteristic for the precision rectifier circuit shown below is (assume ideal OP-AMP and practical diodes)

Assuming the OP-AMP to be ideal, the voltage gain of the amplifier shown below is