In the following circuit the output $$'V'$$ follows an equation of the form
$${{{d^2}V} \over {d{t^2}}} + a.{{dV} \over {dt}} + bV = f\left( t \right).$$
Find $$a,b$$ and $$f(t)$$

$$(a)$$ For the circuit shown in figure

$$(i)$$ Calculate the transfer function $${{{V_0}} \over {{V_i}}}$$
$$(ii)$$ plot the amplitude and phase response as a function for $$R = {R_1}$$

In a common Emitter amplifier, the un bypassed emitter resistance provides

The voltage series feedback in a feedback amplifier leads to