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# KTU B.TECH S3 MODEL QUESTIONS ELECTRONICS CIRCUIT

THIRD SEMESTER B.TECH  DEGREE EXAMINATION  JANUARY 2017

EC 205 Electronics Circuit
Time: 3 Hrs                                                                                                          Marks: 100
PART A

1. Elaborate on integrator circuit. Discuss its response for step, pulse and square wave inputs.
2. Derive the condition for the circuit to work as an integrator?
3. An emitter follower circuit is having beta = 100 and R1 = 30K, R2 = 5K, Vcc = 20V. Calculate Ri and Av?
4. Draw the small signal equivalent circuit of a CC amplifier and derive the expression for input resistance, output resistance, voltage gain and current gain.

PART B

1. Draw the small signal equivalent circuit of a series feedback amplifier and derive the expression for input resistance, output resistance and voltage gain with feedback?
2. An amplifier with open loop voltage gain 2000±150 is available. It is necessary to have an amplifier whose voltage gain varies no more than ±0.2%. Find the reverse transmission factor beta and the gain with feedback.
3. Draw the circuit of a Wien bridge oscillator and explain its working.
4. Explain
ii)Feedback topologies
PART C
1. For a common source MOSFET amplifier, the following parameters and circuit components are given: VGS(Q) = 2.12 V, VDD = 5 V, RD = 2.5 K, VTH = 1 V, Kn = 0.8

mA/V2 and Z = .02/V. Assume the transistor is in saturation, determine its voltage gain.
1. Analyze a MOS differential amplifier and obtain the expression for the CMRR.
2. What is body effect? Deduce the small signal equivalent circuit of an n-channel MOSFET including body effect?
3. With relevant sketches explain the working of bootstrap sweep Circuit?
4. Derive the expression for conversion efficiency, total load power, collector dissipation and figure of merit of a transformer coupled power amplifier?
5. Draw the circuit of a series voltage regulator and explain its working? Also derive the expression for input regulation factor and output resistance?