×

Close

- Electronic Circuit Analysis and Design - ECAD
- 2017
- PYQ
**Sree vidyanikethan engineering college -**- Electronics and Communication Engineering
- B.Tech
**299 Views**- 12 Offline Downloads
- Uploaded 6 months ago

CODE No.:16BT30401 SVEC-16 SREE VIDYANIKETHAN ENGINEERING COLLEGE (An Autonomous Institution, Affiliated to JNTUA, Ananthapuramu) II B.Tech I Semester (SVEC-16) Regular Examinations November - 2017 ELECTRONIC CIRCUIT ANALYSIS AND DESIGN [ Electronics and Communication Engineering ] Time: 3 hours Max. Marks: 70 Answer One Question from each Unit All questions carry equal marks 1 For the transistor shown below, Compute Ai, Av, Avs, Zi and Zo. Assume hic=1100Ω, hfc=100, hrc=1 and hoc=24×10-6 mhos. 2 a) b) 3 a) b) 4 5 a) b) 6 a) b) CO4 (OR) With a neat sketch, explain about the cascade amplifiers. CO1 Two FET based amplifiers with gains of 30 dB are cascaded together. CO4 Find the overall gain. Also find bandwidth of the overall circuit, if individual lower and higher 3 dB frequencies are 20 Hz and 20 kHz respectively. Draw the equivalent circuit of hybrid-model and derive the expression for CO1 hybrid -π impedance in terms of low frequency h-parameters. Derive the equation for gm, which gives relation between gm, IC and CO2 temperature. (OR) Derive the expressions for voltage gain, current gain, input and output CO2 resistances of a CD amplifier at high frequencies. Derive expressions for voltage gain, input resistance and output resistance for voltage series feedback amplifier with the help of neat diagram. A negative feedback of β=2.5×10-3 is applied to an amplifier of open loop gain 1000. Calculate the change in overall gain of the feedback amplifier if the gain of the internal amplifier is reducing by 20%. (OR) Derive the expression for frequency and conditions of oscillation of RC phase shift oscillator using BJT. A phase shift oscillator using BJT has the following circuit constants R1=R2=R3=3.2KΩ, RL=10KΩ, C1=C2=C3=20nF. Calculate the frequency of oscillations. 1 14 Marks 7 Marks 7 Marks 8 Marks 6 Marks 14 Marks CO1 8 Marks CO2 6 Marks CO2 10 Marks CO2 4 Marks

7 a) b) 8 a) b) 9 a) b) 10 a) b) Derive the expression for maximum theoretical efficiency in the case of class B push pull amplifier. Why is it named so? What are its advantages and disadvantages? Design a class B power amplifier to deliver 30W to a load resistor RL=40Ω using a transformer coupling. Vm=Vcc=30V. Assume reasonable data wherever necessary. (OR) What is class A amplifier? Derive the expression for maximum value of efficiency. VCE(max)=15V, VCE(min)=1V, find the overall efficiency for i) Series–fed load ii) Transformer-coupled load CO2 8 Marks CO3 6 Marks CO1 10 Marks CO4 4 Marks Draw the equivalent circuit of capacitance coupled single tuned amplifier and derive the equation for voltage gain. Differentiate the single tuned and double tuned amplifiers. (OR) What is a Q-factor? Derive the expression for Q-factor of a capacitor. Explain the effect of cascading single tuned amplifiers on bandwidth. CO1 10 Marks CO1 4 Marks CO1 CO2 6 Marks 8 Marks 2

## Leave your Comments