17EE34
Fifth semester B.E. Degree Examination
Analog Electronic Circuits- Model paper
Time 3 hrs Max. Marks:100
Note: Answer FIVE full questions, choosing one full question from each module
Module 1
1. Explain with the help of a neat circuit diagram the operation of a double ended
clipping. 6M
A Voltage divider bias circuit has R1 47 kΩ, R2 10 kΩ, Rc 2.2 kΩ, RE 560Ω, Vcc 14v. The
silicon transistor used has β of 100. Determine the Q-point and SICO for the circuit. 8M
Explain the various time components involved in practical transistor switching. 6M
OR
2. What is a clamping circuit? Analyze the circuit given in Fig Q2a. draw the output
waveform.
Fig. Q2a 8M
For the collector feedback biasing circuit given in fig Q2b determine the Q point and
SIXO. 8M
Fig. Q2b
Derive the expression for SICO for a fixed bias CE amplifier circuit. 4M
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Module 2
3. With the help of h-parameter model deduce an expression for voltage gain, input
impedance and output impedance for an voltage divider biased amplifier with RE
un-bypassed. Discuss the significance of un-bypassing RE 8M
A transistor in CE mode has hie 1100Ω, hre 2.5x10-4, hfe 100, hoe 25μA/V. Find Voltage
gain, input impedance, output impedance and output impedance. Take RL Rs 1KΩ. 8M
A transistor in CE mode has h-parameter hie 1100Ω, hre 2.5x10-4, hfe 100, hoe
25μA/V. Determine the equivalent CB parameters. 4M
OR
4. Derive expression for input impedance, voltage gain and output impedance for an Emitter
follower circuit using h-parameter model for the transistor. 6M
A Voltage divider bias circuit has R1 47 kΩ, R2 10 kΩ, Rc 2.2 kΩ, RE 560Ω, Vcc 14v.
Assuming RE is bypassed determine voltage gain, input impedance and output impedance. Take
the h-parameters of the transistor to be hie 1100Ω, hfe 100, hoe 25μA/V. 8M
State and prove millers theorem. 6M
Module 3
5. What is a Darlington pair? Justify why it's called super-β transistor? 6M
Discuss the advantages of using negative feedback. 6M
Derive an expression for voltage gain with feedback and input impedance with
feedback for a current series feedback circuit. 8 M
OR
6. With the help of a neat circuit diagram explain cascade connection. 6M
What do you understand by positive and negative feedback? Mention the various
types of feedback amplifiers. 6M
Determine the voltage gain, input impedance and output impedance with feedback
for voltage series feedback having A Zin 10kΩ and Zo 20kΩ for feedback of
β -0.2 ii) β 0.6. 8M
Module 4
7. Explain the operation of a Class-B push pull power amplifier. Prove that the maximum
efficiency of a class-B configuration is 78.5%. 8M
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A power amplifier has harmonic distortion D2 0.1, D3 0.02, D4= 0.01, the fundamental
current amplitude is I1 4A and RL 8 ohms. Calculate the total harmonic distortion,
with and without push pull configuration. 6M
With a circuit diagram explain how barkhausen criterion is satisfied in RC phase shift
oscillator. Give the expression for frequency of oscillation and the minimum hfe value for
sustained oscillation. 6M
OR
8. Explain the operation of Class A transformer coupled power amplifier and prove that
the maximum efficiency is 50%. 8M
Calculate the efficiency of class B push-pull power amplifier for a supply voltage of Vcc 22V
driving a 4Ω load with peak output voltages of Vm 22v Vm 20v Vm 04v
6M
A collpits oscillator has C1 0.01μF, C2 0.01μF and L 1 mH. Calculate the frequency of
oscillation and what should be the minimum gain of the circuit. 6M
Module 5
9. Discuss the construction, working and characteristics of an n-channel JFET. 8M
Draw the transfer characteristics for n-channel JFET with Take IDSS 8mA, VP -4v.
4M
For the voltage divider biased JFET circuit has R1 3.3MΩ, R2 330kΩ, RD 2kΩ and
RS 1.2kΩ. Take IDSS 8mA, VP -4v. Determine the value of IDQ, VGSQ and VDS.
8M
OR
10. Discuss the construction, working and characteristics of an enhancement type
MOSFET. 8M
With necessary equivalent circuit obtain the expression for voltage gain, input impedance
output impedance for a fixed biased CS- JFET amplifier. 8M
Draw the transfer characteristics for p-channel JFET with Take IDSS 8mA, VP 4v.
4M