4th Semester Electronic and Communication Engineering (2013-December) Question Papers

USN

Time: 3 hrs.

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3a.b.

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4a.

Fourth Semester B.E. Degree Examination, Dec.2013/Jan.2ol4Engineering Mathematies - lV

Max. Marks:100

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O6MAT41

series up to fourlh

(06 Marks)

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Note: Answer FIVEfull questions, selectingat least TWO questionsfrom euch part.

PART _ A

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Applying Taylor's series method, find'y'at x:0.1 by considering the

{=*+v2-v(0):1.degree term. Given O, 1.

Find y at x: 0.2 using Runge Kutta

step size 0.2.

x 0 0.1 0.2 0.3

! I I .1 169 1.2733 t.5049

fourth order method. Given {y - y-*, y(0) : 1 and

dx y+x(07 Marks)

dvUse Milne's predictor corrector formulae to find y(0.4). Given # = ,,, + y). with

(Use comector formula twice.)

/ ;) :2 \If(z) in a regular tunction of 'z' show that I + * *l t ffrl l' = 4lf'@)l' .

[ 6"' Ay' )'

tction f(z) :u * iv where , = ;n,l#;r 2-Findthebilineartransformationwhichmapsthepoints z:1, i, -1 intothepoint w:2,i,-2.Also find the invariant points of the transformation. (07 Marks)

:,". ":11:* au*ly's theorem under complex values tunctiol tl.:rl",t"r. (06 Marks)

Expand f1z; = in Laurent's series valid tbr (i) lzl < 1, (ii) I <lzl<2.10t Marks)lz-r)(z-2)

Evaluate l r"ot1., dz where 'c' is lz - 1l : 1 using Cauchy's residue theorem. (07 Marks)! (r-Y,)'

12 r

Solve 14* r9+ y =0 using the method ofsolution in seriesdx' dx

1 d'.)With usual notation prove that P, (") = fr# (x' - 1)n .

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Express xo - 3x' + x in terms of Legendre's polynomials.

PART _ B5 a. Fit a curve in the form y : a t U* T .7Uy-tn method of least squares for the data given

ffifrx.-/9tN;e NAg82/

x 1 1.5 2 2.5 J 3.5 4

v 1.1 1.3 t.6 2 2.7 3.4 4.1

below:

(06 Marks)

lnes o

x 1 2aJ 4 5

v 2 5aJ 8 7

5 b. Obtain the two li ssions for the data given below:

and hence findffirrelation between x and y'

7a.

b.

Find the (@ distributions of x and Y,

The contents of the three wns are as given below:

Urn 1: 1 white ball,2 red balls, 3 greenballs'

lJrn2:2 white, 1 red and 1 greenball'

Urn 3: 4 white, 5 red and 3 green balls' .1 - - ---Two balls are drawn from i randomly chosen urn and are found to the one white and one

;;r. ;;;i;rr. p."u"unirv that the bails so drawn came from the third urn' (07 Marks)

FindthemeanandvarianceofPoissondistribution(06Marks)In a certairr town the duration of a shower is exponentially distributed with mean 5 minutes'

#"; ilil pr"u"il1iry that ashower will last for (i) 10 minutes or more' (ii) less than 10

ffi;;,'iiid;i;#10 and 12 minutes? . .. .. (07 Marks)

The marks of 1000 students in an examination foilows a normal distribution with mean 70

and standard deviation of 5. Find the expected number.of, students, whose marks will be:

i) less than 65 ii) more than z5 iil) between 65 and75

iCiu", A(z:1):0.34i31'. (07 Marks)

A coin is tossed 1000 times and head turned up 540 times. Test the hypothesis that the coin

is an unbiased one. r 1 L- 1. (06 Marks)

A sample of 200 tyres is taken from 11o1. The mean life of tyres is found to be 40000 kms

with standard a.riuiio,.or izoo kms. Is it reasonable to assume the mean life of tltes in the

lot as 41000 kms? irro .uuurish 9-5% confidence limits with in which the mean life of tyres

in the lot is expected to lie. . r ,i , . 1 L- -. t. (07 Marks)

Ten individuals are chosen at random from a population and the heights are found to the in

inches 63,63,66",;,";;,*ei, io,70,7l i"d lt lg-tfre light of this data discuss the

suggestion that the *"u, height in the population is 66 inches' If the population mean is

unknown, obtain q-0%-co"fiae"nce limits foithis mean. (07 Marks)

O6MAT41

(07 Marks)

c.

c.

c.

8 a. The joint distribution for two random variables x arid y is given below:

(ii) covariance of x and Y.(06 Marks)

b. Find the unique fixed probability vector of the regular stochastic matrix

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- I I 107Marks)P =l y y, o | \- "-.---'

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A software .ngin.e, goes to his work place every day by motor bike or by car' he never goes

by bike on two .orrrJ*ir. days, but if he goes by car on a day then he is equally likely to

go by car or by bik;;;the next day. Find t[e transition matrix for the chain of the mode of

transport. If car is used on the first day of a week find the probability that (i) bike is used, (ii)

;;;'";, o, ,r,. 5,n ;;. (07 Marks)

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USN 10ES42

Fourth Semester B.E. Degree Examination, Dec.2013 /Jan.201.4Microcontrollers

Time: 3 hrs. Max. Marks:100

Not e : :: ;::; ;ir; {::: l :x ;: : ; :"::;'#f ,PART _ A

I a. Define rrdcrocontroller. Differentiate between microprocessor and microiontroller.,, ",, (05 Marks)

b. With the ,"ai diugrum, explain the 8051 architecture. ' "'. ' (10 Marks)c. Briefly explain the dual functions of port-3 pins of 8051. (05 Marks)

2 a. What is addressin!";o0., Put the number OFAH in registers R:, & and R5 in four differentaddressing modes. (06 Marks)

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b. Explain the following in brief,i) The pin that connects external memory.ii) The port that has open-drain output.iii) The register that sequences the program execution.iv) PSW. (08 Marks)

c. Showthe stack contents, sp contentsandContents of anyregister affected after each step ofthe following sequences of operation:

MOV SP. #7OHMOV R5. #3OHMOV A. #44HAdd A. R5MOV R4. APUSH4 .,,,'"'PUSH 5 '

POP4 '

Explain the different types of conditional and unconditional jump instructionsSpecify the different ranges associated with jump instructions.

(06 Marks)

of 8051.(08 Marks)

3a.

b.

c.

4a.b.

C^

Find the address of first two internal RAM locations between 20H and 40H, which containsconsecutive numbers. If so, set the carry flag to one, else clear the carry flag. (06 Marks)Write an 8051 assembly time delay subroutine to generate a time delay of 100 prsec whencalled. Assume crystal liequency as 12 MHz. Show delay calculations. Do not use timers.

Give bit size and data range details for the widely used seven 'C' datat.ypes of 80r::u

*"uod

(04 Marks)Write an 8051 ALP to convert packed BCD number 48 to ASCII and display the result onport-2 and port-3. (06 Marks)Write an ALP 8051 program to find the checksum byte of data stream 30H, 4AH, 65H and10H. Convert the binary value of checksum into decimal and display the value of the BCD

":$ltx

digits on ports Po, Pr and Pz.

I of2(10 Marks)

,,"1"'t*'. iil) Explain mode-2 operation. uo lv!'fir':K$r)

"":4= - u. *ii . an ALp to generate a square wave continuously of 2 kHz with a duty cycle of66"A

..,' ff,6r; A switch is connected to the pin Pl.2. Write a 'C' program to monitor the swi$ch d create

10ES42

PART - B

5 a. With regard to timers of 8051:

i) Explain briefly the difference between the timer and counter operation.

ii Indicate how io starVstop the timer if GATE control is also used. ,,rl

:::\ E-,-r^:- ^^Ao-) nnerqfinn (06 ltfffi,,liit"

,xn.=,hhs following frequencies on pin P1.7: i,-.q..'l

q"'i$: *,.Wh.n SW : 0; 500H2

ii),"lrWhen SW = l;750H2 :,.

U-r"i@ir"U mode 1 for both of them. ,,,', 't\' (08 Marks)

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6 a. what i, ;6id; communication? How serial communication id carried out with RS232 in

so51? u'''# -,.= " :: (06 Marks)

b. Explain the bit p&;h of SCON register' , =

' " (06 Marks)

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i) ALP to transfer'se;ia$y letter 'A' continuously' ,,.ii) C program to recelve,pty-tes of data and p,g;!thdfriin Pl. Use 9600 baud rate, 8-bits and

one st-op bit, for both t$ailsmission and qe'et$gtion. Use timer 1, mode-2. (08 Marks)

"'f' ,.'::=':iu =t \io

7 a. Explain briefly the MSP430 RISC+Q'ru,arc ftecture. (10 Marks)

b. Give details of register of MSP430. "'':F'r'* (10 Marks)

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8 Write short notes on: .;-' -"

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A, RTC fl

b. DMA 65'= '.hc. DAS d".;

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(20 Marks)

"{d: RF interfaces.

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USN 06ES43

block diagram and determine the transfer

(10 Marks)

Time: 3 hrs.

Fourth Semester B.E. Degree Examination, Dec. 20l3lJan.2014Gontrol Systems

Max. Marks:100Note: 1. Answer FIVEfull questions, selecting

atleast TWO questions from each part.2. Missing data, tf any, muy be suitable assumed.

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. PART -A

I a. Define a control system. Explain with examples, open loop and clssed loop control systems.(10 Marks)List the merits and demerits of open loop and closed loop control systems.

b. For the mechanieal system shown in Fig. Ql(b),D Draw the medhanical networkii) Write the differential equations describing the systemiii) Draw the F - V analogous electrical circuit ater writing the corresponding electrical

equations. 1 (l0 Marks)

2 a. For the circuit shown in Fig. Q2(a). Draw the

1rr.1ior, -S($ , using block diagram rules.Y (s)

For the system represented by the

signal flow graph, techniqueX: Xt t Cr:U

i, =-0,x,+xr+crrU

Xz =-pzXr +cr,U.

Fig. Q2(a)

following equations, find the transfer function x(s)

byU(S)

Fig. Q1(b)

(10 Marks)

3a.

b.

06ES43Explain the following time domain specifications of a second order systems, with neatsketch i) Peak time ii) Delay time iii) Rise time iv) maximum over shoot v) Settling time.

(06 Marks)

A system described uv * * lgv + 25y(t)= 50x(t) ,' dt' dtEvaluate the response and maximum output for a step of 2.5 units. (08 Marks)In the block shown in Fig. Q3(c) G(s) : A/S2 and H(S) : (ms +n). For A: 10, determine thevalues of m and n for a step input with a time constant 0.l sec ; which give a peak over shoot

c.

of30%o. (06 Marks)

(08 Marks)feedback system having closed loop

(06 Marks)

(08 Marks)

4a.

b.

6a.

b.

ta.b.

What are the.difficulties encountered while assessing Routh - Hurwitz criteria and how doyou eliminate these difficulties, explain with examples. ,,, ,r' (06 Marks)The open loop transfer function of a feedback control system is given by

G(S)H(S) = ------K--S(s+4Xs'+2s+2)i) Using R- H cretarian determine the range of "K'' for which the system will be stableii) If a zero at S : -4 is added to the forward transfer function, how is the stability affected?

Using R - H cretarian, find the stability of a unity-qr

lransfer function G(S) = e -

S(s + 2)

5 a. State the different rules for ttretoriiru.,,:lH;l,o"rr.b. A feedback control system has open loop transfer {hnction :

G(S)H(S) =* 't"''

S(s + 4)(s2"+ 4s + 20)

Plot the root locus.fot K:0 to co indicate all points on it. (12 Marks)

Explain co-rel{tion between time domain and frequency domai4 for second order systems.,, (06 Marks)The opeh loop transfer function of unity feedback control system is given by.,::',.' Kn/Q\Ll/c\

,''' s(l+0.001s)(1+0.25s)(l+0.1s) ,,,,,Determine the value of K, so that the system will have a phase margin of 40o, what will bethe gain margin. Use code plot. (t4 Marks)

State and explain Nyquist stability cretarian. (06 Marks)Using Nyquist stability cretarian. find the range of K for closed - loop stability

G(s)H(s)= . K K>0.S(s'+2s+2)

Explain properties and significance of state transition matrix.

, t.

(14 Marks)' .

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(10 Marks)A linear time invariant system is characterizedby the homogeneous state equation :

ft

li l=[, 0l [.1Lo, ] [t r-] L*,.1

Compute the solution of homogeneous equation assume the initial state vector. (10 Marks)

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t0EC44USN

Fourth Semester B.E. Degree Examination, Dec.2013 lJan.2ol4Signals and Systems

Time: 3 hrs.

Ia.

Note: Answer FIVEfull questions, selectingat least TWO questions from esch port.

PART _ ASketch the even and odd part of the signal shown in Fig.Ql(a).

Max. Marks:100,],

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'..'.,., Fig.Ql(a)b. Check whether the following signals is periodic or not'and if periodic find its fundamental

period.(i) x(n): cos(2Onn) + sin(50nn) (ii) x(t) = [cos(2nt)]2

c. Let x(t) and y(t) as shown in Fig.Ql(c). Sketch (i) x(t)y(t - 1) (ii) x(t)y(-t -1)

Y(r)

t

2a.

b.

3a.

b.

Fig.Q1(c)Determine the convolution sum of the given sequences

x(n) = {1; -2,3, -3} and h(n) = {-2,2,-2\' ,l\,lrlll

Performthe convolution of the following sequences:

" xl(t):e-at ; 0<t<T,,,:::::::

:,," xz(t):1 ; 0<t<27:..::

G. ,q.n LTl system is characterized by an impulse response,

response of the system for the input x(n; = [1]'r,rr.t4t\,./

Find the natural response of the system described by a differential equation

d2y(t) "

dy(t)dr, *. d, + 2y(t) =2x(t). with y(0) : l. and #1,=, = o

(10 Marks)

/r\nh1n;=l- l ,(n). Find the

|') I\L /

Determine the following LT1 systems characterued by impulse reponse is memory, causal

and stable.(i) h(n) : 2u(n) - 2u(n-2) (ii) h(n) : (0.99)'u(n + 6). (06 Marks)

1 of2

(06 Marks)

t0EC44c. Find the difference equation description for the system shown in Fig.Q3(c). (04 Marks)

Fie.Q3(c)d. By converting the differential equation to integral equation draw the direct form-I and direct

Y ("1

form-Il implementation for the system as

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d'y(t) * 1 dy(t) = x(t) * u

d2x(t)

dtr .*

dt' -t

d, -n\t/ I v dt2

"...., PART_B .

a. Find the DTFT of the following signals:

(04 Marks)

4a.

b.

State and prove the following properties of DTFS: (i) Modulation (ir) Parseval's,ni,%riil;u.,

Find theFourier series coefficients of the signal x(t) shown in Fig.Q4(b) and also draw itsspectra. (10 Marks)

-Tr flFie.Qs(b)

(i) x(n):unl' lal<1 (iil x(n) :2'u(-n) (08 Marks)(06 Marks)

(06 Marks)

b. Determine the signal x(n) if its DTFT is as shown in Fig.Q5(b).c. Compute the Fourier transform of the signal

fl+cosnt : lti<lx(t) = 1|. 0 : ltl>la. Find the frequency respanse of the system described by the impulse response

h(t) : a(r) - 2e 2t i(t)and also draw its magnitude and phase spectra.

b. Obtain the Fourier translorm representation for the periodic signalx(t) : sin wot

and draw the magnitude and phase.

c. A signal'x(t): cos(20nt) + % cos(30nt) is sampled with sampling periodNyqaisf rate.

a. ffiat is region of convergence (ROC)? Mention its properties.b: ' Determine the z-transform and ROC of the sequence x(n) = riu(n) + riu(-n).

l+z-'C. Determine the inverse z-transform of the function, x(z) = l-z-t +0.52-2 'fraction expanslon.

8 a. An LT1 system is described by the equationy(n): x(n) + 0.8 x(n- 1) + 0.8x(n -2) -0.49y(n-2)

b. Determine the transfer function H(z) of the system and also sketch the poles and zeros.(06 Marks)

c. Determine whether the system described by the equationy(n):x(n) + by(n- 1) is causal and stablewhere lb l< 1. (08Marks)

Find the unilateral z-transform for the sequence y(n) : x(n - 2), where x(n) : o'. (06 Marks)-r-:;-

(08 Marks)

(07 Marks)

tr. Find the(05 Marks)

(06 Marks)

, (07 Marks)

using partial

(07 Marks)

Fig.QaG)

USN

Time: 3 hrs.

la.b.

c.

2a.b.

Fourth Semester B.E. Degree Examination, Dec.2013 lJan.2ol4Fundamentals of HDL

Max. Marks:100

06EC45

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Note: Answer FIVE full questions, selectingat least TWO questions from each poit.

PART _ ACornpare VHDL and Verilog.What are values that std-logic (VHDL) and nets (verilog) can take?With proper example explain the logical operators of verilog.

What are the facts of data flow description?

3a.b.

Starting from the basics draw the logic symbol of D'latch exoitation table, K map circuit forD latch and write VI{DL and verilog program for the sr}me. (10 Marks)

c. Write a data flow description (in both VHDL and verilog) of a full adder with enable. If theenable is low (0). the sum and carry are zero; otherwise the sum and carry are usual outputsof the adder. Use a 5 ns delay for any gate inoluding xor. Draw the truth table of this adder

(08 Marks)

(10 Marks)Write a program in VHDL and verilog for JK flip flop using if & else if statements.

b. Write VHDL behavioral description of a tristate buffer. Use this as nent for

and derive the Boolean function after minimization.

With syntax explain different types of loops in VHDL and verilog.

(10 Marks)

4 a. What is binding? Explain the binding between entity and components in VHDL and betweentwo modules in verilog. (t0 Marks)

5a.b.

structural of 2 to 4 decoder with tristate output.

PART _ BWrite VHDL procedure and verilog task for N-bit ripple caffyWith suita-ble example write VHDL code for writing integers to a

6 a. Give an example of a VHDL package.b. write the block diagram and function table of a SRAM of 16x8 and writd

the same.

using two half adders.b. Discuss the facts and limitations of mixed language description.

8 a. Draw the flow chart and explain the steps involved in synthesis.b. Write a program in VHDL and obtain the gate level synthesis

input and ADH is the output. BP varies from 0 to 7 and ADHthat if BP is more than 5 the ADH is 0. For BP > 2 and lessADH:_5*BP+25

verilog code for

, (12 Mark$

7 a. How to invoke a verilog module from a VHDL module? Giving an example of a full adder' --'--^D(10 Marks)(10 Marks)

(10 Marks)for BP and ADH. BP is thevaries from 0 to 16. Assumethan 5 the ADH is given by

(10 Marks)

(10 Marks)

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USN068C46

Max. Marks:100

coupled inverting amplifier. Also, design an

voltage gain is to be 75 and the output voltage(10 Marks)

Fourth Semester B.E. Degree Examination, Dec.2013 lJan.2014

Linear lGs and APPlications

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Time: 3 hrs.Note: Answer FIVE full questions, selecting

at least TlyO questions from each part.

PART - Af ftr\r -'r'

I a. Define the following opamp parameters and mention their typical values for IC 7

i) Input voltage rangeii) CMRRiii) Input offset voltageiv) Slew ratev) Input impedanee.

b. With a neat circuit diagram, explain directinverting amplifier using a,741 opamp. The

amplitude is to be 3V. Is1,nu*;: 500nA.

2a.

b.

3a.

c.

4a.h.

5a.

b.

Explain a high input impedance capacitof ;oupled voltage follower, with necessary circuit

diagram. (10 Nlarks)

Oesign a capacitor-coupled inverting amplifier to operate with a +20V supply. The

minimum input signal level is, 50mV, the voltage gain is to be 68, the load resistance is

500Q, and the lower cutoff frequency is to be 2,00 Hz. Use a74l opamp. (10 Marks)

What are the effects of slew rate oni) Bandwidthii) Output amplitude and

iii) Output pulse rise time. ' (06 Marks)

With a neat eircuit diagram, explain Zin Mod technique of frequency compensu,totb. Marks)

What precautions should be observed for opamp circuit stability? Draw the necessary

With a neat circuit diagram, explain instrumentation amplifier. (08 Marks)

Explain the operatio, of high lnput impedance full-wave precision rectifier with necessary

diagram. Draw the voltage waveforms at various points in the circuit and write the

appropriate equations to show that full-wave rectification is performed. (12 Marks)

PART _ B

With a neat circuit diagram and waveforms, explain operation

waveform generator with frequency and duty cycle controls.of a triangular/rectangular

Explain and design an RC phase - shift oscillator with following specifications:

supply voltage : +15V. IC 741is to be used.

(10 Marks)fo:5 kHz,

(10 Marks).

(10 Marks)

l of 2

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I

06F,.C46

6 a. Explain the operation of an inverting Schmitt trigger circuit with different UTP and LTPlevels. Discuss the design procedure and also indicate the input/output characteristics for thesame. (10 Marks)

b. Design a second-order high-pass active filter to have a cutoff frequency of 10 kHz. Use a

IBrmar): l.5prA. (l0Marks)"''lll '

7 "'"" a,. Explain the terms line regulation, load regulation and ripple rejection for a, dc voltage:. iegulator. ' i '(06 Marks)

b. W,,tthaneat schematic, explainthe salient features of 723 regulator. (08Marks)c. Expffilhe principle of operation of a switching regulator. (06 Marks)

. ..... ;

8 Write short notes on the following:a. 555 timer as mono.stable. multivibrator.b. Voltage-controlled oscillator.c. R-2R ladder Oae-,,,,,,.. .

." ' .;.''

d. Servo tracking ADC. (20 Marks)

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