This document is a model paper for the third semester B.E. degree examination in Analog Circuits. It contains 10 questions testing various concepts in analog circuits. Students are instructed to answer any 1 question from each pair of questions 1-10. The questions cover topics such as biasing, small signal modeling, MOSFET capacitances, feedback amplifiers, instrumentation amplifiers, filters, oscillators and timers.

1. (Page 1 of 2)
Dr. Ambedkar Institute of Technology, Bangalore – 560056
(An Autonomous Institution Affiliated to Visvesvaraya Technological University, Belgaum)
USN: 18EC41
Third Semester B. E. Degree (Autonomous) Semester End Examination (SEE), Nov/Dec 2019
Model Paper
Analog Circuits
Time: 3 Hours Maximum Marks: 100
Instructions to students:
1. Answer any one question from
1 OR 2, 3 OR 4, 5 OR 6, 7 OR 8, 9 OR 10,
Q. No Questions Marks CO RBT
Cognitive
Level
1. a) Describe biasing using a collector to base feedback resistor. 10 CO2 L1
2
b)
a)
b)
Design a circuit of collector to base feedback resistor to
obtain a dc emitter current of 1mA and to ensure 2V max and
min signal swing at the collector. Given VCE = 2.3V Vcc =
10V and β = 100.
Derive the expression of emitter current and the input
resistance at the emitter.
Explain biasing using a constant current source.
10
10
10
CO1
CO1
CO3
L2
L2
L2
3. a) Describe the small signal model of Common source
amplifier.
10 CO2 L2
b) A transistor amplifier is fed with a signal source having an
open-circuit voltage vsig of 10mV and an internal resistance
Rsig of 100kΩ. The voltage vi at the amplifier input and the
output voltage vo are measured both without and with a load
resistance RL = 10kΩ connected to the amplifier output are
as fallows. Find all the amplifier parameters. Given
Vi(mV) Vo(mV)
Without RL 9 90
With RL 8 70
10 CO3 L1
4. a) Mention various capacitances in MOSFET at high
frequencies and their values in cut off, saturation and non
saturation region.
10 CO2 L6
b) Summarize CS, CS with source resistance, common gate and
common drain amplifiers.
10 CO3 L1
5. a) Differentiate between four basic feedback topologies. 10 CO3 L2
b) The non inverting op-amp configuration shown in figure
provides a direct implementation of the feedback loop.
i). Assume that the op amp has infinite input resistance and
10 CO4 L4

2. (Page 2 of 2)
Dr. Ambedkar Institute of Technology, Bangalore – 560056
(An Autonomous Institution Affiliated to Visvesvaraya Technological University, Belgaum)
zero output resistance., Find and expression for the feedback
factor β
6. a) Describe the methods to reduce nonlinear distortion in
amplifier cicuits.
10 CO4 L2
b) Explain Class B Transformer coupled Amplifier. 10 CO3 L3
7. a) Derive the expression for input resistance and output
resistance with feedback in operation amplifiers.
10 CO5 L4
b) Briefly describe summing, scaling and averaging amplifiers. 10 CO4 L2
8. a)
b)
Explain with block diagram of an instrumentation amplifier
system.
Describe the working of schmit trigger.
10
10
CO3
CO2
L4
L2
9. a)
b)
Differentiate between first order and second order
butterworth filter.
Design a second order low pass filter at a high cutoff
frequency of 1kHz and draw frequency response of the
network.
10
10
CO4
CO5
L2
L2
10 a)
b)
Explain voltage controlled oscillator.
Describe 555 timer with neat block diagram.
10
10
CO2
CO2
L4
L2