R13
Code: 13A01403
B.Tech II Year II Semester (R13) Supplementary Examinations December/January 2015/2016
ENVIRONMENTAL SCIENCE
(Common to CE, ME, ECE and EIE)
Time: 3 hours
Max. Marks: 70
PART – A
(Compulsory Question)
1
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
*****
Answer the following: (10 X 02 = 20 Marks)
Define environment. When world’s environmental day is celebrated?
The author of the book silent spring is ---------. The book is written about ---------Define Biodiversity. Classify two hotspots of biodiversity in India.
Define Ecosystem. Estuary ecosystem mean -----------Write the unit to measure the thickness of ozone layers. In which layer, ozone layer is present?
Define acid rain. Expand BOD.
Explain sustainable development.
3Rs rule is -----------Aids day is on ------------- world’s population day is on ------.
Define value education.
PART – B
(Answer all five units, 5 X 10 = 50 Marks)
UNIT – I
2
3
Environmental studies require the basic knowledge from different subjects. Analyze multi-disciplinary
nature of environmental studies.
OR
Discuss ill effects of deforestation.
UNIT – II
4
5
Technology owes Ecology an apology. Justify your answer to support the given statement.
OR
Explain conservation of Biodiversity. List out five endemic species of India.
UNIT – III
6
7
Generate new techniques/methods to replace chemical pesticides and chemical fertilizers to prevent soil
pollution.
OR
Describe the sources, effects and controlling measures of water pollution.
UNIT – IV
8
9
Analyze how ozone layer depletion takes place.
OR
Present salient features of wildlife Act.
UNIT – V
10
11
Population growth is the major problem for all environmental problems. Narrate your answer.
OR
Write the role of IT in environmental education.
*****
R13
Code: 13A03304
B.Tech II Year II Semester (R13) Supplementary Examinations December/January 2015/2016
ENGINEERING GRAPHICS
(Electronics and Communication Engineering)
Time: 3 hours
Max. Marks: 70
(Answer all five units, 5 X 14 = 70 Marks)
All questions carry equal marks
*****
UNIT – I
1
(a)
(b)
2
Draw all alphabet and numerical of 12 mm height using single stroke vertical letters as per the Indian
standard.
Draw a Heptagon having 30 mm sides such that one of its edges is vertical.
OR
Draw the epicycloids and hypocycloid, when generating circle and directing circle are of 40 mm and 140 mm
diameters respectively. Construct the evolutes of the two curves.
UNIT – II
3
(a)
(b)
4
(a)
(b)
A point P is situated in first quadrant. It is 50 mm above HP and 35 mm in front of VP. Draw its projections
and find its shortest distance from the intersection of HP and VP and the auxiliary plane.
A 90 mm long line is parallel to and 25 mm in front of the VP. It s one end is in the HP, while the other end is
50 mm above the HP. Draw its projections and find its inclination with the HP.
OR
A point Q is situated in the first quadrant. It is 40 mm above HP and 30 mm in front of VP. Draw its
projections and find its shortest distance from the intersection of HP and VP and auxiliary plane.
The front view of a line, inclined at 30 to the VP is 65 mm long. Draw the projections of the line, when it is
parallel to and 40 mm above the HP, its one end being 30 mm in front of the VP.
UNIT – III
5
6
(a)
(b)
A thin hexagonal piece of metal sheet with a 40 mm side has a hole with a 30 mm diameter punched
centrally. It is placed on a corner in the HP. Its surface is inclined at 30 to the HP and the top view of the
diagonal through the corner in the HP makes an angle 45 with the VP. Draw its projections.
OR
Draw the projections of a cone, having base 30 mm diameter and 65 mm axis, when it is resting on one of
its generators on the ground:
The generator is inclined at 30 to HP.
The axis is inclined at 30 to the VP.
UNIT – IV
7
8
A pentagonal pyramid of base edge 30 mm and height 60 mm is resting on its base with one base edge
perpendicular to VP. A cutting plane inclined at 50 with HP & perpendicular to VP and passing through a
corner cuts the pyramid. Draw the sectional front view, top view. Also draw the true shape of the section.
OR
A funnel tapers from a circular opening of diameter 70 mm to a circular opening of diameter 20 mm over an
axial length of 50 mm. It is extended axially a further 40 mm with a cylindrical portion. Develop the surface of
the funnel.
UNIT – V
9
10
A cone of base diameter 60 mm and height 70 mm is resting on its base on HP. It is cut by a plane
perpendicular to the VP and inclined at 30 to the HP. The plane meets the axis at a distance of 25 mm from
the apex. Draw the isometric view if the truncated cone.
OR
Draw three views of a cone, base 50 mm diameter and axis 75 mm long, having one of its generators in the
VP and inclined at 30 to the HP, the apex being in the HP.
*****
R13/SS
Code: 13A04303
B.Tech II Year II Semester (R13) Supplementary Examinations December/January 2015/2016
SWITCHING THEORY & LOGIC DESIGN
(Common to EEE and ECE)
Time: 3 hours
Max. Marks: 70
PART – A
(Compulsory Question)
1
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
*****
Answer the following: (10 X 02 = 20 Marks)
State and Prove consensus theorem.
Find the 2’s complement of representation of -9.
Design a XOR gate using minimum number of NAND gates.
Find the minimum number of literals for the following function using 2 variable Karnaugh Map.
F = =∑m (1) + d (3).
d - Don’t care.
Write the sum and carry expression for half adder.
Implement the function F =∑m (0, 2) using a 2 × 4 decoder.
Write the characteristic equation for JK Flip-flop.
How many states are there in a n-bit ring counter?
Compare PROM & PAL.
What is meant by cycle in asynchronous circuits?
PART – B
(Answer all five units, 5 X 10 = 50 Marks)
UNIT – I
2
(a)
(b)
3
(a)
(b)
Express the following function F = xy + x’ y in a product of max-terms.
Check if NOR gate is associative or not.
OR
Show that a positive logic NAND gate is a negative logic OR gate
Obtain the truth table of the following function and express in sum of min-terms and product of maxterms: F = (A’ + B).(B’ + C).
UNIT – II
4
(a)
(b)
5
Simplify the Boolean function using K map technique:
F = π M (3, 4, 6, 7, 11, 12, 13, 14, 15).
F = ∑m (0, 1, 2, 4, 5, 6, 8, 9, 12, 13, 14).
OR
Simplify the following Boolean function using tabulation method:
F = ∑m (0, 1, 2, 3, 5, 7, 8, 10, 14, 15).
UNIT – III
6
7
(a)
(b)
Design a 4-Bit Magnitude comparator using logic gates.
OR
Implement the function F = ∑m (0, 1, 2, 4, 5, 8, 11, 12, 15) using 8:1 multiplexer.
Design a half subtractor using logic gates.
UNIT – IV
8
9
Design a 4 bit universal shift register with neat diagram.
OR
Design a 3 bit synchronous up counter using T Flip-flops.
UNIT – V
10
11
Implement the following functions using PLA with three inputs, four product terms and two outputs.
F1 (A, B, C) = ∑m (3, 5, 6, 7), F2 (A, B, C) = ∑m (0, 2, 4, 7).
OR
Implement the switching function F = ∑m (1, 3, 5, 7, 8, 9, 14, 15) by a static hazard free two level ANDOR network.
*****
R13
Code: 13A04401
B.Tech II Year II Semester (R13) Supplementary Examinations December/January 2015/2016
PULSE & DIGITAL CIRCUITS
(Common to ECE and EIE)
Time: 3 hours
Max. Marks: 70
PART – A
(Compulsory Question)
1
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
*****
Answer the following: (10 X 02 = 20 Marks)
Derive an expression for the upper cut-off frequency of a low-pass circuit.
When does a high – pass circuit act as a differentiator?
State and prove the clamping circuit theorem.
Write the applications of voltage comparators.
Write the methods of improving resolution of a binary.
Draw a neat schematic of the gated astable multivibrator.
Write the methods of generating a time-base waveform.
What do you mean by relaxation circuit? Give a few examples of relaxation circuits.
What are the applications of sampling gates?
Draw circuits of AND, OR and NOT gates using transistors.
PART – B
(Answer all five units, 5 X 10 = 50 Marks)
UNIT – I
2
(a)
A step generator of 50 Ω impedance applies a 10 V step of 2.2 ns rise time to a series combination of a
capacitance C and a resistance R = 50 Ω. There appears across R a pulse of amplitude 1 V. Find the
value of the capacitance C.
Briefly discuss about Attenuators.
OR
Consider the response for an exponential input Vi(t) =
applied to a high pass RC circuit.
Derive the expression for V0(t) when
and when n = 1.
(b)
Prove that the peak of the output pulse occurs at:
(a)
(b)
3
UNIT – II
4
(a)
(b)
5
(a)
(b)
Discuss the various diode clipping circuits that operate with two independent clipping levels.
Draw the circuit to obtain the pulse – type comparator output.
OR
Draw Emitter coupled clipper circuit neatly and discuss in detail.
Draw the typical diagram of clamping circuit taking source and diode resistances into account.
UNIT – III
6
(a)
(b)
7
(a)
(b)
Derive the expression for UTP for emitter coupled binary.
Find the ratio VCC/V, if a voltage – to – frequency converter generates oscillations of frequency twice of
that when V = VCC.
OR
Design a self-biased symmetrical binary with the following specifications: VCC = 10 V, RC = 1 kΩ,
VBE(sat) = 0.3 V, βON = 20, operating frequency up to 80 kHz, impedances of the triggering
sources = 250 Ω.
What is the purpose of commutating capacitors?
Contd. in page 2
Page 1 of 2
R13
Code: 13A04401
UNIT – IV
8
(a)
(b)
9
(a)
(b)
Explain Transistor Bootstrap time-base generator with the help of circuit.
Draw the Transistorized Miller time-base generator.
OR
Explain in detail about phase delay and phase jitters.
Explain a sweep generator with synchronization signal with the aid of its circuit.
UNIT – V
10
(a)
(b)
11
(a)
(b)
With a neat circuit diagram, explain the six-diode sampling gate.
Briefly discuss about Chopper Amplifiers.
OR
Write the comparisons between different logic families.
Analyze the RTL, DTL, TTL and ECL.
*****
Page 2 of 2
R13
Code: 13A04402
B.Tech II Year II Semester (R13) Supplementary Examinations December/January 2015/2016
ELECTRONIC CIRCUITS ANALYSIS & DESIGN
(Common to ECE and EIE)
Time: 3 hours
Max. Marks: 70
PART – A
(Compulsory Question)
1
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
*****
Answer the following: (10 X 02 = 20 Marks)
How are amplifiers classified according to the transistor configuration?
What is the difference between Darlington pair and Cascode amplifier?
Draw the hybrid π equivalent circuit of BJTs.
The input power to a device is 10,000 W at a voltage of 1000 V. The output power is 500 W and the
output impedance is 20 Ω. Find the power gain in decibels.
Define positive and negative feedback of the amplifier.
What are the conditions for oscillations?
What is the function of power amplifier?
Why heat sink is necessary in case of power transistor?
What is a tuned amplifier? Mention its advantages and disadvantages.
What is Q factor?
PART – B
(Answer all five units, 5 X 10 = 50 Marks)
UNIT – I
2
(a)
(b)
3
Draw the circuit of Common Emitter Amplifier and its equivalent circuit. List out its characteristics.
For the emitter follower with RS = 500 Ω and RL = 5 kΩ, Calculate AI, AV,AVS and Ro. Assume hfe = 50,
hie = 1 kΩ, hoe = 25 mA/V.
OR
Draw the circuit diagram of two stages RC coupled transistor amplifier. Explain the operation and
calculate the mid frequency range and low frequency range.
UNIT – II
4
5
(a)
(b)
Derive the expression for CE short circuit current gain and explain the same for resistive load.
OR
Explain the effect of Coupling and Bypass Capacitor in CE amplifier.
A BJT has the following parameters measured at Ιc = 1 mA; hie = 3 kΩ, hfe = 100, fT = 4 MHz, CC = 2 pF,
and Ce =18 pF. Find rb’e, rbb’, gm ,fH for RL = 1 kΩ.
UNIT – III
6
(a)
(b)
7
(a)
(b)
A voltage series negative feedback amplifier has a voltage gain without feedback of A = 500, input
resistance Ri = 2 K, output resistance Ro = 15 K and feedback ratio = 0.01. Calculate the voltage gain,
input resistance and output resistance of the amplifier with feedback.
Explain the concept of feedback with block diagram.
OR
Discuss about amplitude & frequency stability in oscillators.
With neat diagram explain about crystal oscillator.
Contd. in page 2
Page 1 of 2
R13
Code: 13A04402
UNIT – IV
8
(a)
(b)
9
(a)
(b)
Draw the circuit diagram of class-A power amplifier with transformer coupled. Explain operation and
calculate the efficiency.
What are the advantages and disadvantages of push pull configuration? Show that in class –B push pull
amplifier the maximum conversion efficiency is 78.5%.
OR
A transistor in a transformer coupled (class – A) power amplifier has to deliver a maximum of 5 W to a
load of 4 Ω. The quiescent point is adjusted for symmetrical swing, and the collector supply voltage is
VCC = 20 Volts. Assume Vmin = 0 volts.
(i) What is the transformer turns ratio?
(ii) What is the peak collector current?
Compare the series fed and transformer coupled class – A power amplifiers. Why is the conversion
efficiency doubled in transformer coupled class – A amplifier?
UNIT – V
10
(a)
(b)
11
(a)
(b)
Explain the working of single tuned amplifier. Draw the frequency response
Explain the operation of a double tuned amplifier. Explain the advantages of double tuned circuit over
single tuned circuit
OR
Explain the effect of cascading single tuned amplifier on band width
Derive the expression for bandwidth in terms of resonant frequency and quality factor in case of double
tuned amplifiers.
*****
Page 2 of 2
R13
Code: 13A04404
B.Tech II Year II Semester (R13) Supplementary Examinations December/January 2015/2016
ANALOG COMMUNICATION SYSTEMS
(Electronics and Communication Engineering)
Time: 3 hours
Max. Marks: 70
PART – A
(Compulsory Question)
1
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
*****
Answer the following: (10 X 02 = 20 Marks)
Derive the expression for the percentage power saving in AM-SSB-SC with respect to AM-DSB-FC
under Tone Modulation.
A periodic symmetric square wave signal of period 2 Sec is defined as:
It modulates a Carrier
using AM-DSB-FC. Find the side band power of the resulting
Modulating signal.
An FM signal
is sent through a circuit whose
.
Find the bandwidth of the output of the circuit.
Explain why PM is not used for Broadcasting.
Define the power spectral density of: (i) Band limited white noise. (ii) Band pass white noise.
A Two port network with an available gain
is driven by a noisy resistor. Find the expression for
the available noise power at the output of the network.
Explain why a PWM signal cannot be demodulated directly with an LPF, even though its magnitude
spectrum resembles that of PAM signal.
Find the Trigonometric Fourier series coefficient
of
.
A discrete memory less source with entropy 2 bits/message is connected to a communication channel.
If the conditional entropy of the source is 1 bit/message, find the rate at which the information is
conveyed to the user if the message rate of the source is 500.
Find the capacity of the channel whose noise matrix is a square matrix and having all the elements of
the matrix same.
PART – B
(Answer all five units, 5 X 10 = 50 Marks)
UNIT – I
2
(a)
(b)
(c)
3
(a)
(b)
Derive the expression for the Modulation efficiency of the AM signal
, where
is the Modulation index and
is the base band signal.
Explain the Principle involved in generating AM-DSB-SC signal using Ring modulator.
An AM modulator has an output given by
. The
un-modulated carrier power is 100 watts and the Transmission efficiency of the AM signal is 40%.
Find A and B.
OR
Explain the process of Modulation and Demodulation in QAM.
A DSB SC Modulated signal
is synchronously demodulated using a local carrier
. Find the maximum value of the ratio between the output power and input power of the
Demodulator.
Contd. in page 2
Page 1 of 2
R13
Code: 13A04404
UNIT – II
4
(a)
(b)
(c)
5
(a)
(b)
Justify that one form of Angle modulation can be obtained from the other.
Justify that the Angle modulation is a Non-linear modulation method.
An Angle Modulated signal is given by
. Assuming it as PM
signal, find the Modulation Index and Band width if: (i) Modulating signal frequency is doubled.
(ii) Modulating signal frequency is halved.
OR
In an Armstrong Modulator, an NBFM signal with carrier frequency 200 KHz and frequency deviation
25 Hz is passed through a cascade of frequency multiplier 1 (Multiplication factor = 64),
a mixer with one of the input as 10.8 MHz, Local Oscillator and another frequency multiplier 2
(Multiplication factor = 48). Find the frequency deviation and the carrier frequency of the signal at the
output of the frequency multiplier 2.
Derive Carson’s rule for the Bandwidth of an FM signal.
UNIT – III
6
7
(a)
(b)
8
(a)
(b)
(c)
9
(a)
(b)
Verify that both AM-DSB-SC and AM-SSB-SC are of same noise performance.
OR
Find the Noise bandwidth of an RC low pass filter and the relation with its 3dB bandwidth.
An amplifier operating over the frequency range of 445 KHz to 460 KHz has a 200 Kohms input resistor.
What is the r.m.s noise voltage at the input of the amplifier if the ambient temperature is
UNIT – IV
Explain about Aperture effect distortion.
Explain the method of converting PPM signal into PWM signal.
A baseband signal m(t) band limited to 10 KHz is sampled using Flat Top sampling. What is the
maximum allowed width of the sample so that the signal can be recovered without any distortion?
OR
Derive and plot the Magnitude spectrum of PWM signal.
Explain the principle of signal recovery through Holding.
UNIT – V
10
(a)
(b)
11
(a)
(b)
Derive the expression for the capacity of a BSC.
A memory less source has the alphabet
with corresponding probabilities
If the source is quantized according to the quantization rule
find the entropy of the
quantized source.
OR
Derive Hartley-Shannon’s Law.
An analog signal is band limited to 4 KHz and is sampled at its Nyquist rate. The samples are
quantized into 4 levels. Find the information rate of the source if (i) The probability of occurrence of the
inner two levels are three times that of the extreme two levels. (ii) All the levels are equally likely.
*****
Page 2 of 2