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a. Explain Reverse recovery time of a semiconductor diode.

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

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

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

b. Derive the expression for l_{S}, V_{CE} and S(I_{CO}) for voltage divider bias using exact analysis.

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.

a. For common base configuration shown in Fig Q3(a). Find r_{es}, z_{s}, z_{o}, 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.

c. Using h-parameter model for a transistor in C.E configuration. Derive expressions for A_{i}, z_{i} and A_{v}.

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.

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

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

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

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

6. Derive the expression for input resistance ( R_{if})for voltage series feedback amplifier .

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

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%.

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.

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

b. i) The frequency sensitive arms of the wien bridge oscillator uses C_{1} = C_{2} =0.001 and R_{1} = White R_{2} is kept variable. The frequency is to be varied from 10KHz to 50KHz by varying R. Find the minimum and maximum values of R_{2}.

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 C_{1} =100pF and C_{2} = 50pF.

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.

a. Define transconductance g_{m} and derive expression for gm.

b. With equivalent model of JFET common drain configuration. Obtain the expression for z_{i}, z_{o }and A_{v}.

c. For common gate amplifier as shown in Fig 08.(c), gm = 2.8ms, r_{d} =50 Calculate z_{s}, z_{o}, and Av.

Ipjugaad