Analog Electronic Circuits

a. Explain the need of cascade amplifier and list the advantage of this Circuit.

c. For common gate amplifier as shown in  Fig 08.(c), gm = 2.8ms, r_d =50 Calculate z_s, z_o, and Av.

b. With equivalent model of JFET common drain configuration. Obtain the expression for z_i, z_o and A_v. 

a. Define transconductance g_m and derive expression for gm.

c. With neat circuit explain the working of series resonant crystal oscillator. A crystal has L =0.1H ,C =0.01 pF find the series resonating frequency.

ii) Design the value of an inductor to be used in Colpitts oscillator to generate a frequency of 10MHz. The circuit is used a value of C₁ =100pF and C₂ = 50pF. 

b.  i) The frequency sensitive arms of the wien bridge oscillator uses C₁ = C₂ =0.001  and R₁ =  White R₂ is kept variable. The frequency is to be varied from 10KHz to 50KHz by varying R. Find the minimum and maximum values of R₂. 

a. With neat circuit diagram explain the operation of BJT Hartley oscillator.

c. What is Harmonic distortion? Calculate the harmonic distortion components for an output signal having fundamental amplitude of 2.5V second harmonic amplitude of 0.25V, third harmonic amplitude of 0.1 V and Fourth harmonic amplitude of 0.O5V. Also calculate the total harmonic distortion.

b. Draw the circuit diagram of series fed directly coupled Class - A amplifier. Give the expression for dc power input and ac power output and show that efficiency is 25%. 

a. Draw input and output wave forms of Class A, Class-B and Class - based on the location of Q-point, and briefly discuss. 

6. Derive the expression for input resistance ( R_if)for voltage series feedback amplifier .

b. With block diagram, explain the concept of feedback List the advantages of negative feedback.

a. Explain Reverse recovery time of a semiconductor diode.

c. Draw and explain frequency response of an amplifier and briefly discuss the effect of various capacitors on frequency response.

b. Describe miller effect and derive an equation for miller input and output capacitance.

a. An amplifier consists of 3 identical stages in cascade; the bandwidth of overall amplifier extends from 20Hz to 20kHz. Calculate the band width of Individual stage. 

 c. Using h-parameter model for a transistor in C.E configuration. Derive expressions for A_i, z_i and A_v.

b. Derive an expression for z_i, z_o, A_v and A_i of a CE fixed bias configuration using r_e model.

a. For common base configuration shown in Fig Q3(a). Find r_es, z_s, z_o, and A_v.

c. For the circuit shown in Fig. 02(c). Find I_S, I_C, V_CE. V_C and V_E Assume  = 100,VBE =0.7. 

b. Derive the expression for l_S, V_CE and S(I_CO) for voltage divider bias using exact analysis.

a. What is transistor biasing? Discuss the causes of bias instability in a transistor.

c. What is clamper circuit? Explain the operation of Positive and Negative clamper circuits and draw the wave form. [Assume Ideal Diode). 

b. The Fig. QI (b) shows two way clipper. Determine its output wave form. Assume diode drop of 0.7V.