engg services electronics and telecommunication engineering objective paper 1 2009

8/12/2019 Engg Services Electronics and Telecommunication Engineering Objective Paper 1 2009

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c 'lTtOnrt{'l q{- . . .. ...slinee jn. Service EaaminatioG ::

DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE ASKED TO DO SOT.B.C. : O-FTF-J-FUA Test Booklet Series

Serial 064949TEST BOOKLET

ELECTRONICS AND TELECOMMUNICATION ENGINEERINGPaper ITime Allowed : Two Hours Maximum Marks : 200INSTRUCTIONS

1. IMMEDIATELY AFTER THE COMMENCEMENT OF THE EXAMINATION, YOU SHOULDCHECK THAT THIS TEST BOOKLET DOES NOT HAVE ANY UNPRINTED OR TORNOR MISSING PAGES OR ITEMS ETC. IF SO. GET IT REPLACED BY A COMPLETETEST BOOKLET.2. ENCODE CLEARLY THE TEST BOOKLET SERIES A, B, C, OR D AS THE CASE MAYBE IN THE APPROPRIATE PLACE IN THE ANSWER SHEET.3. You have to enter your Roll Number on the 0 -- - - - - - - - - - - - ,

Test Booklet in the Rox provided alongside.DO NOT write anything else on the Test Booklet.4. This Test Booklet contains 120 items (questions). Each item comprises four responses(answers). You will select the response which you want to mark on the Answer Sheet . Incase you feel that there is more than one correct response, mark the response which you

consider the best. In any case, choose ONLY ONE response for each item. 5. You have to mark all your responses ONLY on the separate Answer Sheet proyided. Seedirections in the Answer Sheet.6. All items carry equal marks.7. Before you proceed to mark in the Answer Sheet the response to various items in the TestBooklet, you have to fill in some particulars in the Answer Sheet as per instructions sent toyou with your Admission Cel: tificate.8. After you have completed filling in all your responses on the Answer Sheet and theexamination has concluded, you should hand over to the Invigilator only the Answer SheetYou are permitted to take away with you the Test Booklet. .9. Sheets for rough work are appended in the Test Booklet at the end.10. Penalty for wrong answers:

THERE WILL BE PENALTY FOR WRONG ANSWERS MARKED BY A CANDIDATE IN THEO J E C T I V ~ ~ TYPE QUESTION PAPERS.i There are four alternatives for the answer to every question. For each question for which a wronganswer has been given by th e candidate, one third (0 33) of the marks assigned to that questionwill be deducted as penalty.(ii) f a candidate gives more than one answer, it will be treated as a wrong answer even if one ofthe given answers happens to be correct and there will be same penalty as above to that question.(iii) f a question is left blank, i .e., no answer is given by the candidate, there win be no penalty fOTthat question .DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE ASKED TO DO SO


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1.

2.

3.

.... . . . . . . .ftl'''' . ~ : ; . . 'tWhich f the .followjng statements IS/are true 4.t . . . for the diamond structure?1. Coordination number is four. -2. Packing fraction is 034 .3. Copper crystallizes into diamond

structure .1. Lattice is FCC.a) 1 onl yb) 1, 2 and 4

(c) 2 and 3 on lyd) 2,3 and 4

Wh ich of the following statements is/are truefor a go od c.onductor of electricity?1.

2

IIts conductivity decreasesincreasing temperature.Number of free electrons is around1028 3.

,with

3 Its conductivity decreases with additionof impu ties. '

1 . It is a good conductor of heat also.a) I , 2, 3 and 4b) 1 only

(e) 2 and 3 only(d) 3 and 4 only

Which of the following materials is o t aninsuJatnr ?a) . Diamondb) Graphite

(e) Bakeli ted) Lucite

5.

6.

7.

O-FTF-J -FUA 2 - A )

Consider the following statements :The conductivity of a me tal has . negatemperature coefficient since:1. The e lectron concentration incre

with temperature . .2. The electron mobility decreases

temperature.3. The electron - lattice scattering

increases with temperature .Which of the above statements icorrect?a) 1 onlyb) 1 and 2

(c) 2 and 3d) 3 on ly

Which of the following is o t a condumaterial ?a ) C o p p ~ rb) Tungstenc). Germaniumd) Platinum

What is the chemical bonding in ssemiconductor?a) Metallic

(b) Ionic(c) Covalentd) Van der Waals

Which one of the following is a trivmaterial?a) Antimony

(b) Phosphorus(e) Arsemc(d) Boron


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The fuse material used in electrical lines must 13.have which one of the following properties? Which one of the following materials is usedfor making permanent magnets?(a) High resistivityb) Low conductivityc) High melting point

(d) Low melting point

Manganin, an alloy of copper and manganese,is used in(a) Soldering material(b) Heating elementsc) Ballast resistors

(d) Standard resistances

Which one of the following pairscorrectly matched ?(a) NaCl Diamagneticb) Gd Paramagneticc) Ferrite Ferrimagneticd) CrZ0 3 erromagnetic

IS ot

Hysteresis loss in a transformer working at220 V and at a frequency of 50 Hz is 100 W.hen the transformer is operated at 220 Vand at a frequency of 100 Hz, what is thehysteresis loss?(a) 50 W(b) 100 W

. (c) 200 W(d ) 400 W

Which of the following. IS ot anelectromagnetic device?(a) Hall transducer(b) Transformerc) Speedometer

(d) Eddy current damping device

14.

(a) Steelb) Carbonc) Carbon-SteeLd) Graphite

What happens when a paramagnetic m aterialis heated above Curie temperature?a) It becomes diamagneticb) It becomes non-magneticc) t becomes ferromagneticd) t becomes anti-ferromagnetic

15. Ferr()magnetic m t ~ r i l s show hysteresis inB - H characteristic. As the magnetic field isincreased sl )wly fr )m zero value , what is thefirst process which sets in the material to givenet magnetization ?

16:

(a) Growth of favourably oriented domainsat the cost of other domains byreversible boundary displacements

b) Growth of favourably orien ted domrunsat the cost of other domains byirreversible boundary displacements

c) Dorpain wall orientati()nd) A combinati()n )f processes (a) and c)ab )ve

The [ )llowing properties are ass()ciated withferroelectric materials :1.2.

Its susceptibility is negative.The susceptibility is expressed asc where c is the Curie= T-Tcconstant and is the Curietemperature.

3. t has permanent dipoles orientedrandomly .

Which of the above statements is/are correct?(a) 1 qnlyb) 1 and 3

(e) 2 onlyd) 1 2 and 3

3 - A )


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17. Consider the following:1.2.3.4 .

SiGeGaAsInP

Which of the above semiconductors should beused . for making highly efficientphotodiodes ?a) 1 and 4 onlyb) 3 .and 4 onlyc) 1,3 and 4d) 2, 3 and 4

18. The ma terials not having negativetcmper ture coefficient of resistivity rea) Metalsb) Semiconductorsc) Insulatorsd) None of the above

19. Which one of the following compounds iswidely used for making ferrites ?a) FeOb ) CuO

20. ~ ~ f t ~ t i v e Q of the equivalent electrical circuitof qu artz crystal is of the order ofa) 200b ) 2000c) . 20,000d ) 2,00 ,000

21. In a material, the Fermi level is locabetween the centre of the forbidden band the conduction band. Then what is tmater ia l?a) A p-type semiconductorb) An notype semiconductorc) An intrinsic semiconductor.d) An insulator

22_ Consider the following statements:1 Acceptor level is formed very close to

conduction band.2.

3.

4

The effective mass of the free electrosame as that of a hole .Th e magnit\lde of the charge of a felectron is same as that of a hole.Addition of donor impurities adds hoto the semiconductor.

Which of the above statements are correca) 1 and 3b) 2 and 3c) 2 and 4d) 3 and 4

23 . Diffusion current of holes msemiconductor is proportional to with pconcentration of holes / unit volume)a) dpdx2

b) dpdxc) dpdtd) d 2pdx 2

O-FTF-J-FUA 4 - A )


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, . The junction capacitance of a linearly 27.graded pn junction with applied voltage =Y B) is proportional to

b)

c)

d)

1Y 2B1

y3B

28.

As per Hall effect, if any specimen ca,rrying 29.a CU Tcnt IS placed in a transversemagnetic field B, then an electric field E isinduced in the specimen in the directiona) parallel to Ib) perpendicular to B and parallel to Ic) parallel to I and Bd) perpendicular to both I and B

What current docsJ = Aq Dp + n n2LpND LnN A 1 f represent npn junction diode ? where the symbols

Which of the following quantities can Wt bemeasured/determined using Hall effect ?a) Type of semiconductor p or n)b) Mobility of charge carriersc) Diffusion constantd) Carrier concentration

A junction FET, can be used as a voltagevariable resistora) at pinch-off conditionb) beyond pinch-off voltagec) well below pinch-off conditiond) for any value of V DS

D

I __ OB

SThe above. figure shows the symbol ofa) p channel depletion MOSFETb) p channel enhancement MOSFETc) complementary MOSFETd) p channel JFET

have their usual meaninga) Forward current

b) i f f u ~ i o n current

30 .. The maximum power dissipation capacity of atransistor is 50 m W . If the collector emittervoltage is 10 V, what is the safe collectorcurrent that can be allowed through thetransistor?

c) Drift currentd) Reverse saturation current

5 - A )

a) 5 rnAb) 25 rnAc) 10 rnAd) 25 rnA


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31. Which one of the following statements is 35. In a CMOS CS amplifier, the active loadcorrect for MOSFETS ? obtained by connecting a(a ) p channel MOS is easier to produce

than n channel MOS(b ) n channel MOS must have twice the

area of p channel MOS for the same ONresistance

(c) p channel MOS has faster switchingaction than n channerMOS

(d) p channel MOS has higher packing 36.density than n channel MOS

32. The process of extension of a single-crystalsurface by growing a film in such a waythat th e added atoms form a conti nuationof the single-crystal structure is called(a) Ion implantation

a channel current mirror circuit(b) n channel transistor

(c) p channel transistor(d) BJT current mirror

Which one of the following IS ot LEmaterial?(a) GaAsb GaP

(c) SiC(d) Si02

(b) Chemical vapour deposition(c) Eledroplatillg(d) Epitaxy

37. The minimum energy of a photon requirfor intrinsic excitation is equal to

33. The mru


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- - ---- --

9. A function of one or more variables whkh 42.conveys information on the nature ofphysical phenomenon is called

a) Noise

h) Interferencec) Systemd) Signal

The output y t) of a continuoustimesystem S for the input x t) is given hy -:

ty t) = J X A) dAWhich one of the following is correct ?a) S is linear and time-invarianth) S is linear and -time-varyingc) S is non-linear and time-invariantd) S is non-linear and time-varying

What is the period of the sinusoidal signalx n) = 5 cos [0-2 ltn] ?a) 10

h) 5c) 1d) 0

43.

7 - A I

Transfer function of a certain system isY s) 1=U s) s4 + 55 3 + 85 2 + 65 + 3

Which one of the following will be the A Bmatrix pair of state variable representation ofthis system?

a)

oo

oo

ooo

1oQ

o1o 1 - 0

h)

c}

d )

-3

1oo3

ooo3

Separationmatrix is

6

1oo8

o1o6

1oo6

8

o1o6

oo18

o1o8

property

a) t - to) = t) tIl to)

-5oo13

ooo5

oo15

of _

h) t - to) = tIl-I t) tIl-I tO)c) >Ct - to) = t) tIl-I tO)d) tIl t - tal = tIl-I t) cp l tO)

1

ooo11ooo1ooo

state transition


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44. When yet) F T ) Y jm); x ~ ) F T ) X jm); 47.h(t) f ) H(jm). What is YGIil)?(a) X jm)H jrn)(b) X jm) H jm)c) X jm) +' H jm)d) X jm) - H jm)

45. For a senes R-L-C circuit, the characteristicequation is given as

82 + R s + _1_ = 0L L C .If is denoted by a and ~ by p, then

21, LCunder the condition of p > a2 the system~ ~

. 46.

a) critically damped(b) under dampedc) undamped

(d) over damped

100 V1 0 Q

100 Q - 50V

In the above circuit the switch has been inposition 1 for quite a long time. At t = 0 theswitch is moved to position 2. At this positionwhat is the time constanta) 0.1. sb) 1 s

(e) 0 11 s(d) l s

O-FTF-JFUA

49_

IQ 1 Qi t i

50 mH ve

1In the above circuit, the switch is open folong time. At time t = 0, the switch is closWhat are the initial and final valuesvoltages across the inductor?a) 0 V Rnd 0 Vb) 0 V and 80 Vc) 80 V Rnd 0 V

(d) 80 V and 80 V

The voltage applied to an R-L circuit at twhen switch is closed is 100 cos.(100 t + 3The circuit resistance is 80 Q and inductais 06 H (in - which initial current is zeWhat is the maximum amplitude of currflowing through the circuit?a) 1 Ab) 2 Ac) 5 A

(d) 10 A

A sImes R-C circuit with R = 3 Q aXc = 4 Q .at 50 Hz is supplied withvoltage V = 50 + 141 -4 sin 314 t. Whatthe RMS value of the current flowthrough the circuit ?a) 5 A

(b) 10 A(cl 20 Ad) 22-36 A


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52. Which one of the following is applicable to IInynetwork linear or non linear, active orpassive, time-varying or invariant - as long+

5 cos (100 t + 45 ) 004 F as Kirchhoff s laws are ot violated?

What is the approximate steady statecurrent in the above circuit ?(a ) 50 Ab) 25 Ac) 5 Ad) 1 A

Consider th e following statements regardingthe propert ies of an R-L-C series circuitunder resonance :1. Current in the

applied voltage.circuit IS In phase with

2. Voltage drop across capacitor C andinductance L are equal in magnitude.

3 .

4.

Voltage across the capacitor is equal Inmagnitude to the applied voltage.Current in the circuit is maximum

Which of the above statements islarecorrect?a) 1 only

(b ) 1, 2 and 4(e) 2 and 4(d ) 1,3 lind 4

(a) Tellegen s theorem(b) Reciprocity theorem(e) Maximum power transfer theorem(d) Superposition theorem

53. Number of fundamental cutsets of any graphwill be

54.

(a) same as the number of twigs(b ) same as the number of tree branches(c) same as the number of nodes(d) equal to one

If in an electric network R, L and Ca r econnected in series and supplied by a voltagesource then its dual network will be describedby the differential equation:a)

c)

(d)

vet) = Ri(t) + L diet) + 1: J tt) dtdt C( ) 1 . ( ) C di et) 1 J )v t = - t + - - + - ) t tG . dt .L

itt) = Gv(t ) + C dv( t ) + 1: J et) dtdt Lvet) = Ri(t) + L diet) + C J t t ) dtdt

55 . In a network with twelve circuit clements andfive nodes, what is the minimum number ofmesh equations ?a) 24

(b) 12c) 10d ) 8

9 - A )


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56. With respect to transmission parameters, 58.whi.ch one of the following is correct ? Which one of the following driving pfunctions does not represent an

network?(a) A and B are dimensionless

57.

(b) Band C are dimensionless(c) A and D are dimensionless(d) Band D are dimensionless

Match List I with List II and select theL Orrcct answer using the code glVen belowthe lists

List INetwork

parameter

A.

B. A

C. C

D

Code:A B

a) 1 4(b) 3 4c) 1 2

(d) 3 2

2.

3.

4.

C2244

List IIMeasured underopen circuitconditions

D3131

J = 01

I =02

I =02

59.

60.

OFTF-J-FUA ( 10 - A )

a)

(b)

(c)

d)

Z s) = --;;-S_(_5_+-;:3;-)_(s2 + 1) (52 + 9)

Z(s) = (8 2 + 25)8(s2 +36)

Z(s) = (8 2 + 1 (s2 + 36)S(82 + 4) (82 + 25) .

Z(s) = S(82 + 16)(s2 + 25)

If a two-port network is reciprocal as was symmetrical, which one of the followrelationships is correct ?a)

(b)

(c) A D - B C = l and A = D(d) All of the above

If th e ' connection of two two-ports is 5that the transmission matrix of the ovenetwork is the 'product of the transmissmatrices of the indi; ;dual networks, wtype of connection is it ?(a) Series connection(b) Cascade connection(c) Parallel connection(d) None of the above


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2HI I I 6

IH 64. All poles and zeros of a driving pointimmittance function of an L-C network

Z s - l Q l Q

Consider the ahove network. Impedance ofthis network as a function of the complexfrequency s consists of a certain number ofzeros and poles. What is the location of poles? 65.a) - 2(b) ' 2(e) 2d) 2

(a) should lie on the jm axisb) should lie on the + ve real axisc) should lie on the - vc rea l axis

(d) can lie anywhere in s-plane

In the field of a charge Q a t the ongm, thepotentials at A 2 , 0 , 0) and B(I/2, 0, 0) amV = 15 volt and VB = 30 volt respectively.What will be the potential at cn, 0, 0) ?(a) 25 voltb) 225 voltc) 20 volt

Consider the following network function d ) 175 voltN(s) = s(s ~ 2 . .

s+4) s+1+J1) s+I-J1)In order to make N(s) as rational networkfunction , it is essential to include(a) Zero at origin(b) Zero at infinityc) Pole at origind) Pole at inlinity

66. What will be the equipotential surfaces for apair of equal and opposite line charges?(a) Spheresb) Concentric cylindersc) .Non-concentric cylindersd) None of the above

67. I f the potential functions VIand V 2 satisfyFor determining the network functions of a Laplace s equation within a closed regiontwo po.rt network it is required to considerthat(a) all initial conditions remain same(b) all initial conditions are zeroc) part of initial conditions are equal to .

zerod) initial conditions vary depending on

nature of network

I - A )

and assume. the same values on its surface,then which of the following is correct ?(a) V, and V2 are identical(b) V, is inversely proportional to V2c) V1 has the same direction as V2

(d) V, has the same magnitude as V2 buthas different rurection


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68. Ifof

V = sinhLaplace's

x cos ky . ePz Isa solution 71.equation, what will be the

Who de veloped the concept of time . varyelectric field producing a magnetic field ?

value of k ?(a) 1

b p 2 .

(b) . 1 + p2

(c) 1~ 1 _ p 2

(d) ~ 1 - p2

69. By what name is the equation V J = 0frequently known ?a) Poisson s equationh) Laplaces equation

(a) Gauss(b) Faraday(c) Hertz(d) Maxwell

72. A single turn loop is situated in air, withuniform magnetic field normal to its plaThe area of the loop is 5 m2 and the rof change of flux density is 2 WblmWhat is the emf appearing at the terminof the loop?a) - 5 Vb) - 2 V

(c) - 04 Vd) 0 V

(e) Continuity equation for steady currents 73. Which of the following equations resufrom the circuital form of Ampere s law ?

(d) Displacement equation

70. Method of images 1S applicable to whichfields ?(a) Electrostatic fields only(b) E lectrodynamic fields only(c) Neither electrostatic fields nor

electrodynamic fields(d) Both electrostatic fields and

electrodynEl' 'ic fields

(a) iJBV x E -ath ) V B = 0

(c) V . D = p. aD, (d) V x H =J + -. at

74. In which direction is the plane waVe- 8 A AE = 50 sin (10 t + 2z) a y VIm (where a ythe unit vector in y ~ d i r e c t i o n , travelling?(a ) along y direction(b) along -y direction(e) along z direction(d ) along -;z direction

O-FTF-J-FUA . 12 - A )


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For parallel plane waveguides, which is the 78.mode with lowest cutoff frequency ?

Consider the following statements :For a 10 m long common powerconnecting a switch to a i;ght bulb

line

(b) TM10c) TEM

(d) TEll

For plane wave propagating in free space ortwo conductor transmission line, what mustbe the relationship between the phasevelocity vp the group velocity v g and speedof light c ?a) v p> c > V g

(b) v p c V g

c) v p = c = V g

d) vp Vg c

The reflection coefficient on a 500 m longtransmission . line has a phase angle of- 150'. If th e operating wavelength is150 m, 'hat will be the number .of voltagemaxima on the lin ?a) 0b) 3c) 6

(d) 7

L It is a distributed circuit .2. Time delay for propagation through it is

negligible.3. It is in the form of a shie lded coaxial

cable of circular cross-section.4 As the intensity of the lamp varies, input

impedance of this line also changes.Which of the above statements is/arccorrecta) 1 only

(b) 1 and 2(c) 2 and 3(d) 2 and 4

79. With regard to a transmission line, which ofthe following statements is correct ?(a) Any impedance repeats itself every A/4

on the Smith chart.(b) The S.W.R. =2 circle and the magnitude

of reflection coefficient = 0'5 circlecoincide on the Smith chart.

(c) At any point on a transmission line , thecurrent reflection coefficient IS thereCiprocal of the voltage reflectioncoefficient.

(d) Matching eliminates the reflected wavebetween the source and the matchingdevice location

13 - A


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engg services electronics and telecommunication engineering objective paper 1 2009

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