r15 - gpcet.ac.in · what will be the lower and upper cutoff frequency of the multistage amplifier...

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Code: 15A04401 B.Tech II Year II Semester (R15) Regular Examinations May/June 2017 ELECTRONIC CIRCUIT ANALYSIS (Common to ECE and EIE) Time: 3 hours Max. Marks: 70 PART – A (Compulsory Question) ***** 1 Answer the following: (10 X 02 = 20 Marks) (a) Identify different types of feedback available. (b) Write the condition for generating oscillations. (c) Draw the hybrid equivalent model of CE amplifier. (d) Mention four h-parameters of CE amplifier. (e) Identify different types of coupling used in amplifiers. (f) Write the advantages of multistage amplifier. (g) Draw the circuit of transformer couple power amplifier. (h) Mention the efficiency of class-B power amplifier. (i) List out applications of tuned amplifiers. (j) Draw the circuit diagram of matched capacitive coupled amplifier. PART – B (Answer all five units, 5 X 10 = 50 Marks) UNIT – I 2 Draw the circuit of voltage shunt feedback amplifier and derive the expressions for Av, Ri, Ro. OR 3 (a) Write the advantages and disadvantages of positive and negative feedback. (b) Derive the expression for frequency of Wein bridge oscillator. UNIT – II 4 Explain about Hybrid π capacitance and also briefly discuss miller’s theorem. OR 5 Derive the expressions for hybrid π model parameters g m , g ce , r ce . UNIT – III 6 Explain different types of coupling. When two identical stages are cascaded, obtain voltage gain, current gain and power gain. OR 7 Draw and explain the circuit of cascade amplifier and mention the advantages. UNIT – IV 8 Draw and explain class-B push pull amplifier. OR 9 (a) Compare various types of power amplifier. (b) Write about importance of heat sink in power amplifiers. UNIT – V 10 Derive the expression for Q factor of double tuned amplifier. OR 11 Write the effect of cascading single tuned amplifier on bandwidth. ***** R15

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Page 1: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 15A04401

B.Tech II Year II Semester (R15) Regular Examinations May/June 2017

ELECTRONIC CIRCUIT ANALYSIS

(Common to ECE and EIE)

Time: 3 hours Max. Marks: 70

PART – A

(Compulsory Question)

***** 1 Answer the following: (10 X 02 = 20 Marks)

(a) Identify different types of feedback available.

(b) Write the condition for generating oscillations.

(c) Draw the hybrid equivalent model of CE amplifier.

(d) Mention four h-parameters of CE amplifier.

(e) Identify different types of coupling used in amplifiers.

(f) Write the advantages of multistage amplifier.

(g) Draw the circuit of transformer couple power amplifier.

(h) Mention the efficiency of class-B power amplifier.

(i) List out applications of tuned amplifiers.

(j) Draw the circuit diagram of matched capacitive coupled amplifier.

PART – B

(Answer all five units, 5 X 10 = 50 Marks)

UNIT – I

2 Draw the circuit of voltage shunt feedback amplifier and derive the expressions for Av, Ri, Ro.

OR

3 (a) Write the advantages and disadvantages of positive and negative feedback.

(b) Derive the expression for frequency of Wein bridge oscillator.

UNIT – II

4 Explain about Hybrid π capacitance and also briefly discuss miller’s theorem.

OR

5 Derive the expressions for hybrid π model parameters gm, gce, rce.

UNIT – III

6 Explain different types of coupling. When two identical stages are cascaded, obtain voltage gain, current

gain and power gain.

OR

7 Draw and explain the circuit of cascade amplifier and mention the advantages.

UNIT – IV

8 Draw and explain class-B push pull amplifier.

OR

9 (a) Compare various types of power amplifier.

(b) Write about importance of heat sink in power amplifiers.

UNIT – V

10 Derive the expression for Q factor of double tuned amplifier.

OR

11 Write the effect of cascading single tuned amplifier on bandwidth.

*****

R15

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Code: 13A04402

B.Tech II Year II Semester (R13) Regular Examinations May/June 2015

ELECTRONIC CIRCUITS ANALYSIS & DESIGN

(Common to ECE & EIE) Time: 3 hours Max. Marks: 70

PART – A (Compulsory question)

*****

1 Answer the following: (10 X 02 = 20 Marks)

(a) Voltage gain of a single stage amplifier is 30. Bandwidth is 20 kHz. Two such stages are cascaded. Find the overall

voltage gain and bandwidth.

(b) List out the advantages and disadvantages of RC coupled amplifier.

(c) Draw the frequency response of RC coupled amplifier and indicate bandwidth, low, mid and high frequency ranges.

(d) A multistage amplifier is to be constructed using four identical stages, each of which has a lower cutoff frequency 15

Hz and upper cutoff frequency 30 kHz. What will be the lower and upper cutoff frequency of the multistage amplifier?

(e) Draw the equivalent circuit of transconductance amplifier.

(f) An amplifier has a gain of 300, when the -ve feedback is applied gain is reduced to 240. Find feedback factor.

(g) Differentiate between power amplifier and voltage amplifier.

(h) What are the advantages of push pull amplifier configuration?

(i) List out the advantages of tuned circuit.

(j) Distinguish between single tuned and double tuned amplifiers.

PART – B

(Answer all five units, 5 X 10 = 50 Marks)

UNIT – I 2 (a) Explain the effect of cascading of amplifiers on bandwidth.

(b) Compare various coupling schemes used in amplifiers. (OR)

3 (a) Give the analysis of transformer coupled amplifier in mid band region.

(b) Derive the expression for voltage gain and current gain of cascade amplifier.

UNIT – II 4 (a) Draw the small signal simplified hybrid equivalent circuit of an CE amplifier and discuss the effect of bypass capacitor

on the frequency response of an amplifier.

(b) Determine the low frequency response of CE amplifier using the following specifications:

(OR) 5 (a) Draw the hybrid – π model for a transistor in CE configuration and explain the significance of each component in the

model.

(b) Explain the variation of hybrid parameters with increasing | |, | | and temperature.

UNIT – III 6 (a) What is the effect of –ve feedback on the input impedance of an amplifier?

(b) Derive the expression for frequency of oscillations of RC phase shift oscillator. (OR)

7 (a) State and explain Barkhausen’s criteria.

(b) Explain the working of Hartley oscillator. Also derive the expression for its frequency of oscillations.

UNIT – IV

8 (a) Show the conversion efficiency of transformer coupled class A amplifier is 50%.

(b) Explain the operations of class B push pull amplifier. (OR)

9 (a) Explain ideal and practical performance of class–D amplifier.

(b) What is cross over distortion? Explain how it can be eliminated.

UNIT – V

10 Explain the operation of a single tuned capacitive coupled amplifier and derive the expression for bandwidth.

(OR)

11 (a) Define resonant frequency and derive an expression for the impedance of tuned circuit.

(b) What are the limitations of single tuned amplifiers?

R13

Page 3: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 9A04402

B.Tech II Year II Semester (R09) Supplementary Examinations December/January 2014/2015

ELECTRONIC CIRCUIT ANALYSIS (Common to EIE, E.Con.E & ECE)

Time: 3 hours Max. Marks: 70

Answer any FIVE questions

All questions carry equal marks

*****

1 (a) Explain the classification of amplifiers based on frequency range, type of coupling, power delivered and signal handled.

(b) Derive the expression for Ai, Ri, Av and Ro of CB amplifier circuit shown below.

2 (a) Explain different methods used for coupling multistage amplifiers with their frequency

response.

(b) Five identical stages are coupled, each amplifier having f2 = 100 KHz. Determine theoverall upper cut-off frequency for the five stages.

3 (a) Draw the hybrid - equivalent circuit of BJT and explain the significance of each

parameter. Mention typical values of hybrid - parameters.

(b) Given the following transistor measurements made at IC = 5 mA, VCE = 10 V and at

room temperature hfe = 100, hie = 600 , [Aie] = 10 at 10 MHz, Ce = 3 pF. Find , fT, Ce,

rb’e and rbb.

4 (a) Give the low frequency analysis of FET amplifier.

(b) The gain of an RC coupled 2 stage FET amplifier falls by 90% of the mid band value at

400 KHz. If gm of each FET is 10 mA/V, and total output capacitance for each stage is

20 pF. Calculate the RL required and the stage mid band gain.

5 (a) Draw the circuit diagram of a voltage shunt feedback using BJT and derive expression

for voltage gain with feedback.

(b) Draw the circuit for current shunt amplifier and justify the type of feedback. Derive theexpression for Av, , Ri and Ro for the circuit.

Contd. in page 2

Page 1 of 2

R09

B

+

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Code: 9A04402

6 (a) Why the LC oscillators are not suitable for low frequency applications. Explain the

principle of working of basic LC oscillators.

(b) In a transistorized Hartley oscillator the two inductances are 2 mH and 20 while the

frequency is to be changed from 950 KHz to 2050 KHz. Calculate the range over which

the capacitor is to be varied.

7 (a) Prove that in class A power amplifier if the distortion is 10% then the power given to the

load increased by 1%.

(b) A class B push-pull power amplifier has VCC = 50 V, the collector voltage swing from

VCC down to 10 V with input signal. If the transistors used as maximum power

dissipation rating of 20 W. Calculate

(i) The load presented by the output transformer.

(ii) Power output.

(iii) D.C power input.

(iv) Efficiency of collector circuit.

(v) Power delivered to the load if the transformer efficiency is 85%.

8 (a) With neat circuit diagram, explain the working of double tuned amplifier.

(b) What are advantages of double tuned amplifier? Derive an expression for Ι2 maximum.

*****

Page 2 of 2

R09

http://mothertheresalibrary.blogspot.in/

Page 5: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code :9A04402 1II B.Tech II Semester(R09) Regular Examinations, April/May 2011

ELECTRONIC CIRCUIT ANALYSIS

(Common to Electronics & Instrumentation Engineering, Electronics & Control Engineering,

Electronics & Communication Engineering)

Time: 3 hours Max Marks: 70

Answer any FIVE questions

All questions carry equal marks

⋆ ⋆ ⋆ ⋆ ⋆

1. (a) Draw the small signal hybrid model of CB amplifi er and derive and expression for its

Av ,Ai, Rj & R0.

(b) The h- parameters of CE amplifi er are hie=1100Ω , hf e= 50, hre= 2.5*10−4, hoe= 24µA/v and Rs= 1 kΩ , Rl= 10kΩ . Find the current and voltage gain ,(with and withoutsource resistance) input & output impedances.

2. (a) Describe the operation of transformer coupled amplifi er and also derive the expressionfor its current gain.

(b) With relevant circuit explain the diff erent coupling schems used in amplifi ers.

3. (a) Describe the emitter follower at high frequency and also derive the equation for highercutoff frequency.

(b) With hybrid π equivalent circuit. Derive the expressions for hybrid conductances.

4. (a) Draw the small signal model of MOSFET and derive the Expression for voltage gain ofcommon source amplifi er with unbypassed source resistance.

(b) CD amplifi er Uses FET having rd= 300 kΩ and µ =15. Calculate the output impedanceand voltage gain for the load RL= 300kΩ .

5. (a) With necessary diagram explain about the diff erent feedback techniques in amplifi

ers.

(b) In a voltage shunt feedback amplifi er Rc=3kΩ , Rf=30kΩ , Rs= 8kΩ , hie= 1kΩ , hfe=50,hre=hoe

=0.Find the voltage gain, input impendence and output impendence with feedback.

6. (a) Explain the operation of RC phase shift oscillator and derive the equation for frequencyof oscillation.

(b) With neat diagram explain about crystal oscillator.

7. (a) In class A power amplifi er R1=5Ω , VcEsat=1v, VC Emax=40v, Pc(max)=20w, transformercoupling n=2. Find the efficiency.

(b) What is a phase inverter? How is it employed in class B power amplifi er.

8. (a) With circuit diagram explain the stagger tuning operation. Give necessary graph.

(b) Derive the expression for voltage gain in single tuned capacitive coupled amplifi er.

⋆ ⋆ ⋆ ⋆ ⋆

All JN

TU W

ORLD .IN

Page 6: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code :9A04402 2II B.Tech II Semester(R09) Regular Examinations, April/May 2011

ELECTRONIC CIRCUIT ANALYSIS

(Common to Electronics & Instrumentation Engineering, Electronics & Control Engineering,

Electronics & Communication Engineering)

Time: 3 hours Max Marks: 70

Answer any FIVE questions

All questions carry equal marks

⋆ ⋆ ⋆ ⋆

1. (a) Classify diff erent types of amplifi er?

(b) For the emitter follower with Rs= 0.5kΩ and RL= 5kΩ . calculate Ai,Ri,Av assume hfe =50, hie=1kΩ , hoe=25 µ A/V.

2. Draw the circuit diagram of two stage RC coupled transistor amplifi er? Explain operation.

Calculate the mid frequency range and low frequency range?

3. (a) Derive necessary equation for Hybrid- pi(π ) common emitter transistor model?

(b) An amplifi er rated at 40W output is connected to a 10Ω speaker.

i. calculate the i/p power required if power gain is 25dB.

ii. calculate the i/p voltage if amplifi er voltage gain is 40dB.

4. (a) Draw the circuit diagram of source follower circuit? And calculate the voltage gain, inputadmittance and output admittance?

(b) Draw the circuit symbol for a p- channel MOSFET? And explain the small signal MOSFETcircuit model?

5. (a) Derive the i/p impedance, o/p impedance for voltage series feed back amplifi er?

(b) When the negative feedback is applied to an amplifi er of gain 100 the over all gain falls to50. Calculate:

i. The feed back factor‘ β ’

ii. If the same feedback factor maintained, the value of amplifi er gains required if theover all gain is to be 75.

6. What is principle of oscillator? Draw the circuit diagram and derive the condition for oscilla-tion?

7. Draw the circuit diagram of class A power amplifi ers with transformer coupled? Explainthe operation and calculate the efficiency?

8. (a) Draw the double tuned amplifi er. Explain the operation.

(b) What is stagger tuned amplifi er explain?

⋆ ⋆ ⋆ ⋆

All JN

TU W

ORLD .IN

Page 7: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code :9A04402 3II B.Tech II Semester(R09) Regular Examinations, April/May 2011

ELECTRONIC CIRCUIT ANALYSIS

(Common to Electronics & Instrumentation Engineering, Electronics & Control Engineering,

Electronics & Communication Engineering)

Time: 3 hours Max Marks: 70

Answer any FIVE questions

All questions carry equal marks

⋆ ⋆ ⋆ ⋆ ⋆

1. (a) What are the diff erent types of distortions in amplifi er. Explain each?

(b) By using Hybrid model derive performance characteristics for CB transistor amplifi er.

2. Draw the circuit diagram of transformer coupled transistor amplifi er? Explainoperation , frequency response, advantages and applications.

3. (a) What is millers theory? Derive millers output capacitance using millers eff ect capacitance.

(b) The Input power to a device is 10000W at a voltage of 1000V. The output power is 500Wand output Impendance is 20Ω .

i. Find the power gain in decibles.

ii. Find the voltage gain in decibles.

4. (a) Draw the circuit symbols for P-channel MOSFET? and explain the small signal MOSFET

circuit model?

(b) Calculate the voltage gain, Input admittance, Input capacitance, output resistance forcommon source amplifi er.

5. (a) What are the diff erent types of feedback topologies? Explain with diagrams.

(b) An amplifi er has Av = 1000±100. Determine the feed back needed to keep the gainwith in ± 0.1%. Find Avf?

6. Construct the Hartley oscillator? Explain the operation? Derive the condition for sustainedoscillation?

7. (a) Draw the circuit diagram of class B push pull amplifi er and explain the operation?

(b) A class B push pull power amplifi er is supplied with Vcc= 50V. the signal swingsthe collector voltage down to Vmin= 5V. The total dissipation in both transistors is40W, Find the total power and conversion efficiency.

8. (a) Classify the tuned amplifi er? And what are the limitations.

(b) Draw the single tuned amplifi er explain the operation?

⋆ ⋆ ⋆ ⋆ ⋆

All JN

TU W

ORLD .IN

Page 8: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code :9A04402 4II B.Tech II Semester(R09) Regular Examinations, April/May 2011

ELECTRONIC CIRCUIT ANALYSIS

(Common to Electronics & Instrumentation Engineering, Electronics & Control Engineering,

Electronics & Communication Engineering)

Time: 3 hours Max Marks: 70

Answer any FIVE questions

All questions carry equal marks

⋆ ⋆ ⋆ ⋆ ⋆

1. (a) Draw the small signal model of CE amplifi er and derive the expression for it’ s AI , Av ,

Ri

and R0.

(b) For the emitter follower with Rs= 500Ω and RL= 5kΩ , Calculate AI , Av ,Avs and R0.Assume hfe=50,hie=1k Ω ,hoe= 25mA/V.

2. (a) Draw the circuit for Darlington pair and derive the expressions for A1,Av ,Ri and R0.

(b) Describe the principle of operation of RC coupled cascade amplifi er and analyse the fre-quency response.

3. (a) Derive the expression for CE short circuit current gain and explain the signifi cance of fT

is hybrid π model.

(b) The low frequency parameters of a transistor are given below. Vcc =5v, Ic= 10MA, hie=500Ω , hoe=4*10−5A/V,hfe= 100, hre=10−4, fp=50MHz,Cob= 3pf. Compute the values of allhybrid π parameters.

4. (a) Draw the small signal equivalent circuit of common source amplifi er and derive the ex-pression for voltage gain and output admittance.

(b) A common drain amplifi er has rd = 300kΩ and µ = 15. Calculate the outputimpendence and voltage gain for load resistance Rs= 100k Ω .

5. (a) Draw the equivalent circuit of current amplifi er with current shunt feed back & Derivethe expression for input resistance with feedback.

(b) Discuss in detail about the benefi ts of negative feedback in amplifi ers.

6. (a) Draw the general form of LC oscillators and derive the necessary conditions for oscillations.

(b) Discuss about frequency and amplitude instability in oscillators.

7. (a) With neat circuit explain the operation of transformer coupled class A amplifi er and derivethe expression for efficiency.

(b) Explain the class B push pull amplifi er circuit & derive for its efficiency.

8. (a) What is the eff ect of cascading in Tuned amplifi ers? Derive the relation forBandwidth and no. of stages cascaded.

(b) Distinguish between single Tuned , double tuned and stagger tuned amplifi ers.

⋆ ⋆ ⋆ ⋆ ⋆

All JN

TU W

ORLD .IN

Page 9: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 9A04402

B.Tech II Year II Semester (R09) Regular & Supplementary Examinations, April/May 2013

ELECTRONIC CIRCUIT ANALYSIS (Common to EIE, E,Con.E and ECE)

Time: 3 hours Max Marks: 70 Answer any FIVE questions

All questions carry equal marks *****

*****

1 (a) What are the different types of distribution in amplifier? Explain each.

(b) By using Hybrid model derive performance characteristics for CB transistor amplifier.

2 Draw the circuit diagram of two stage RC-coupled transistor amplifier. Explain operation and

calculate the mid and low frequency ranges.

3 (a) What is miller’s theory? Derive millers’ output capacitance using millers’ effect capacitance.

(b) The input power to a device is 10000 W at a voltage of 1000 V. The output power is 500 W

and output impendence is 20 Ω.

(i) Find the power gain in decibels.

(ii) Find the voltage gain in decibels.

4 (a) Explain the terms “impedance matching” and “cross-over distortion”.

(b) Explain why the complimentary symmetry power amplifier has become more popular in

modern circuits.

5 (a) Draw the equivalent circuit of a capacitance coupled single tuned amplifier and derive the

equation for voltage gain.

(b) Calculate the maximum bandwidth of a cascaded single-tuned amplifier with a gain of 43.4

dB, given gm = 2 m A/v and C = 300 pF.

6 Explain the principle of stagger tuning technique of transformer-coupled amplifier that is used

to obtain band pass characteristic with pass band of 10 KHz.

7 With reference to voltage regulators discuss about:

(a) Output resistance.

(b) Load regulation.

(c) Line regulation.

(d) Stability factor.

(e) Temperature co-efficient.

(f) Ripple regulation.

8 (a) List out the important features of 3-terminal regulators.

(b) What are the limitations of linear regulators over switched mode power supplies?

1

Page 10: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 9A04402

B.Tech II Year II Semester (R09) Regular & Supplementary Examinations, April/May 2013

ELECTRONIC CIRCUIT ANALYSIS (Common to EIE, E,Con.E and ECE)

Time: 3 hours Max Marks: 70 Answer any FIVE questions

All questions carry equal marks *****

*****

1 (a) Draw the circuit of an emitter follower and its equivalent circuit. List out its characteristics.

(b) The h-parameters of the transistor used in CE amplifier are hfe = 50, hie = 1.1 K, hre = 2.5 x

10-4, hoe = 24 . Find out current gain and voltage gain with and without source

resistance, input and output impedances, given that RL = 10 K and RS = 1 K.

2 Draw the circuit diagram of two stages RC coupled transistor amplifier. Explain operation.

Calculate the mid frequency range and low frequency range.

3 (a) Derive the expression for CE short circuit current gain and explain the hybrid model.

(b) The low frequency parameters of a transistor are given below. = 5 V, hoe = 4 × 105 A/V, hfe = 104, fp = 50 MHz, Cob = 3 pf.

Compute the values of all hybrid parameters.

4 (a) What are the two disadvantages of push pull amplifier?

(b) Give the schematic of class B push pull amplifier with complimentary symmetry and explain its working.

5 (a) State the functions and frequency range of operations of tuned amplifiers with relevant

reasons.

(b) Draw the circuit of typical single tuned RF amplifier stage employing a transistor. Explain its

operation. If the tuned circuit contains L = 200 micro Henry, SC = 120 pF and RL = 5 kΩ, calculate its bandwidth.

6 Draw the circuit of a class C – tuned amplifier and explain its operation. Derive the efficiency of the amplifier is 100% making necessary assumption.

7 (a) Explain the need for voltage regulation?

(b) What is meant by voltage multiplier? List out the names of 4 different multipliers. Explain

their working.

8 (a) What are the limitations of 3-terminal regulators?

(b) Design an adjustable voltage source using LM 317 for the following specifications :

and 15 v;

2

Page 11: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 9A04402

B.Tech II Year II Semester (R09) Regular & Supplementary Examinations, April/May 2013

ELECTRONIC CIRCUIT ANALYSIS (Common to EIE, E,Con.E and ECE)

Time: 3 hours Max Marks: 70 Answer any FIVE questions

All questions carry equal marks

*****

*****

1 (a) Draw the small signal model of CE amplifier and derive the expression for it’s AI, AV, Ri and R0.

(b) For the emitter follower with RS = and RL = Calculate and R0. Assume hfe =

50, hie = 1 kΩ, hoe = 25 mA/V.

2 (a) Describe the operation of transformer coupled amplifier and also derive the expression for its

current gain.

(b) With relevant circuit explain the different coupling schemes used in amplifiers.

3 (a) Describe the emitter follower at high frequency and also derive the equation for higher cutoff

frequency.

(b) With hybrid equivalent circuit, derive the expressions for hybrid conductances.

4 (a) Distinguish between cross-over distribution and harmonic distortion. How they can be eliminated?

(b) Determine the component values of class A series feed amplifier to deliver 75 mW of output

power to a load of 4 ohm VCC = 16 V. At the operating point micro Amp, Po(max) = 200

mW.

5 (a) Draw the circuit of double-tuned transformer coupled amplifier. Discuss the nature of the

response of the amplifier for different values = 1;

(b) How many stages are required to obtain gain of A = 100 using a tuned amplifier with BW of 500

KHz at fO = 10 MHz. C = 100 pF and gm = 2 mA/V.

6 (a) Explain the method of adjusting the amplifiers for stabilization of the response.

(b) Explain the low frequency compensation technique to increase the BW of an amplifier.

7 (a) List out different types of voltage regulators. What are the advantages and disadvantages of each

type?

(b) A certain voltage doubler has 20 V rms at its input. What is the output voltage? Sketch the circuit

indicating the input terminals and PIV rating of the diode.

8 (a) Draw the circuit diagram of a 3-terminal regulator as a current source and explain its operation.

(b) Design a voltage regulator using 723 to given an output voltage of 5 V at 0.1 A current. Vi = 10 V

and VSC = 0.65 V.

3

Page 12: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 9A04402

B.Tech II Year II Semester (R09) Regular & Supplementary Examinations, April/May 2013

ELECTRONIC CIRCUIT ANALYSIS (Common to EIE, E,Con.E and ECE)

Time: 3 hours Max Marks: 70 Answer any FIVE questions

All questions carry equal marks

*****

*****

1 (a) Draw the small signal hybrid model of CB amplifier and derive and expression for its AV, Ai, Rj and R0.

(b) The h-parameters of CE amplifier are hie = 1100 Ω, hfe = 50, hre = 2.5 × 104, hoe = 24 v and RS = 1

kΩ, RL = 10 kΩ. Find the current and voltage gain, (with and without source resistance) input & output

impedances.

2 (a) Compare emitter follower and Darlington emitter follower configurations in respect of:

(i) Current gain. (ii) Input impedance. (iii) Voltage gain. (iv) Output impedance.

(b) If four identical amplifiers are cascaded each having Hz, determine the overall lower 3 dB frequency. Assume non interacting stages.

(c) Write a short note on Gain-Band width product of amplifiers.

3 (a) Derive all components in the hybrid π model in terms of h parameters in CE configuration.

(b) Describe the emitter follower at high frequency and also derive the equation for higher cutoff

frequency.

4 (a) Compare series fed and transformer coupled class A power amplifiers.

(b) Draw the circuit of transformer coupled amplifier and explain the operation graphically.

5 (a) Draw a simple BJT tuned amplifier circuit and its ideal response characteristic.

(b) Calculate the resonant frequency, BW and Q of the tuned transformer amplifier with RL = 10 kΩ, C = 30 pF and L = 10 mH and turns ratio = 10.

6 (a) What are the main advantages of class-C RF amplifier and explain its operation with necessary

waveforms?

(b) Mention the 3-methods of stabilization of double-tuned transformer coupled amplifier circuit

performance against the feedback path through the parasitic capacity between input and output and

also mention reasons for neutralization schemes.

7 (a) Explain the limitations of unregulated power supplies. To derive regulated DC output from AC mains,

what are the important building blocks required. Explain about each block.

(b) A certain voltage doubler has 20 V rms at its input. What is the output voltage? Sketch the circuit

indicating the input terminals and PIV rating of the diode for (i) Voltage Tripler and (ii) Quadrupler.

8 (a) Draw the circuit of 7805 voltage regulator and explain its operations. (b) 7824 regulator IC can deliver a maximum current of 700 mA. Design a circuit using 7824 to deliver a

current of 3 A.

4

Page 13: R15 - gpcet.ac.in · What will be the lower and upper cutoff frequency of the multistage amplifier ? (e) Draw the equivalent circuit of transconductance amplifier. (f) An

Code: 9A04402

B.Tech II Year II Semester (R09) Regular & Supplementary Examinations June 2014

ELECTRONIC CIRCUIT ANALYSIS

(Common to EIE, E.Con.E & ECE)

Time: 3 hours Max. Marks: 70

Answer any FIVE questions

All questions carry equal marks

*****

1. (a) Compare CB and CC amplifiers.

(b) A common emitter amplifier is driven by a voltage source of source resistance RS =

800 and the load impedance is RL = 1 k The h parameter values are hfe = 50, hie

= 1.1 k hoe = 1/40 k mhos, hre = 2.5x10-4

. Compute the AI, Ri, Av, Ro using exact

and approximate analysis.

2. (a) Explain about the effect of biasing resistors on Darlington pair and how this problem

is solved.

(b) Derive the current gain and input impedance of a Darlington pair.

3. (a) Obtain an expression for CE short circuit current gain.

(b) A BJT has hie = 6 k and hfe = 224 at Ic = 1 mA with fT = 80 MHz and = 12pF.

Determine (a) gm (b) (c) and (d) at room temperature and a

collector current of 1 mA. Determine the parameters gm, , and of the

small signal high frequency model of the BJT.

4. (a) What is the concept of MOSFET amplifier? Explain.

(b) Draw the circuit diagram of common source amplifier with resistive load? Explain its

operation.

5. (a) What are characteristics of open loop amplifiers? Explain.

(b) An amplifier requires an input signal of 60 mV to produce a certain output. With a

negative feedback to get the same output, the required input signal is 0.5V. The

voltage gain with feedback is 90. Find the loop gain and feedback factor.

6. (a) What is the function of oscillator? Explain.

(b) Draw the circuit diagram of RC phase shift BJT oscillator? Explain its operation?

Show that the frequency of oscillator is f =

7. (a) What are the different types of class power amplifiers and calculate the efficiency of

direct coupled class – A power amplifier.

(b) A class – A power amplifier has a transformer as the load. If the transformer has a

turn ratio of 5 and the secondary load is 100 ohms, determine the maximum ac

power output. Given that zero signal collector current is 100 mA.

8. Obtain the bandwidth of a signal tuned transistor amplifier.

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