In the cascade amplifier circuit shown below, determine the values of R₁, R₂ and R_L. Such that the quiescent current through the transistors is 1mA and the collector voltage V_c1 = 3V, and V_c2 = 6V. Tke V_BE = 0.7V, Transistor $$\beta $$ to be hifgh and base currents to be negligible.

An Amplifier a has 6 dB gain and 50 $$\Omega $$ input and output impedances. The noise figure of this Amplifier as shown in the figure is 3 dB. A cascade of two such Amplifiers as in the figure will have a noise figure of

Negative feedback in

1. Voltage series configuration
2.Current shunt configuration

(a) increases input impedance
(b) decreases input impedance
(c) increases closed loop gain
(d) leads to ascillation.

Consider the circuit given in fig. using an ideal operational Amplifier.

The characteristics of the diode are given by the relation I = I_s $$\left[ {{e^{{{qV} \over {KT}}}} - 1} \right],$$

Where V is the forward voltage across the diode
(a)Express V₀ as a function of V_i assuming V_i> 0.
(b)If R = 100K$$\Omega $$ , I_s = 1$$\mu $$A and $${{KT} \over q}\,\, = \,\,25mV$$