ies electrical engineering paper 1 1999

7/30/2019 IES Electrical Engineering Paper 1 1999

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l r.E.S-{ORJ) 19\19 I ol 15

I ELECTRICAL ENGINEERING J

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PAPER-IVacan t lattice sites n halide crystals causea. plastic defom1ation and ionicconductn' tyb. transparency and diff11sionc. diffusion and ionic conductn'IIYd. plastic defomtalion and trru.lsparenC)In a linear chain of atoms of mteratomicdistance r . U1c first Bri llouin r.one occursbetween wave numbersa - z /l ond +;r /1b - 2,TII OIU/ + 2,TI Ic. Zero and 2n-/ Id. - 1/ c and +111The tempermure coel1kieht of resistanceof an insulator isa posithe and independent oftemperatureb. negatile and independent oftemperaturec. Jegati1e and dependent on temperatured. positil'o and dependent on temperatureMatch Lst I (Dielectric) with List n(Loss-tangent) and select the correctsns" er using the codes g11en be low :List IA TenonB. Po lystyreneC. BakeliteD. GlassList nI 5 10'52. 3 wl3! 5 10 ..4. 7 7 ro'

A B C 0a,bC,d.

1343

22J

4-1I2

3I

Piezoelectric materials owe. their propertyto thea presence ofa centreof symmeli)'b. lacL Qfa cen tre of symmeli)

r.,

7

c. presence of axis of synuuert)d. l a c ~ or ax is of symmetryIr E - E. = 2kT ( B" is Fermi energy andK . the Boltzmann 's constant 1s 8.6 14 xw l eVK'1J. then the probahil iJy thai anelec tron occupies an ertergy leve l E' isa. il.63b 0.5c. U;27d li. J2Match List I (Material) 11i1h L1st II(Superconduc ttng rransmon temperalllfe)>U>d select the conecl sns\1 er:List IA. SnB. Nb., GeC. Y-Ba-Cu oXJdeD. Bi-Sr-Cn -Cu oxideList 11I 23 K2. -IKJ . 125 K-1. 'J(l KCodes:

A B ca. 2 I -1b. 4 I 2c. 4 I 3d. I -1 2

D3323Match L1st (Type of magnetism) "lthList 11 (Material) and select the correct

answerList IA. Dsn1ngneucB. FerromagneticC. i\ntiferromagneticD. ferr(lmagneticLISlllI. Ge2. NiOJ Fenites-1. Cobalt.Codes;

A B c D


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a.h.c.d.

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3232

2323Consider lhe fo llowmg sunements:Pcnnanmi mag net d i p o l e in matter resu ltfrom

L orbital angu lnr momentum of d ectrons2. e c l r o n spin angular momentum3. nuclear spin angular rnomcotwnWhtcl oof hese s tntomc nts are correct?a land2b. I and3c. land 3d. I 2and 3The phcnonocntln l>y which uli:rmma.gnctic marerial is ma_gncli.cd In itsfinal swle b)' a IJIIJgll tlhc licld os allribulcdtoa edd y currents and mngolc lic viscosilyb. magnotic. ~ c o s anil hys1crcsisc. hysteresis and eddy currcntlid. aging and magncric o s ~ ' t ! S1le c11n1:nl on a co il \1 ouod live r "l i ! m m a ~ ; e 1 i c core is gradua lly i n c r e a ~ e c Jto 2 A and tltcn rtduccd lo I A lutd UICIIUte current in it os agam increased 10 ! A.f he variation of magne lizauon of he corawi ll be as shown ina

b.

- I tA)c.

- r t ~ t t

o -1 1M

1 ur1512. The to tlll rru11 loss iro a tra11sformer core atncmnal nux density was measured nt 25r17. and at 50 117 nnd WIJS found 10 bu 250

\II and 800 W rcspcctivcl) ll1c hysteresisloss nt5() liz would bea. 1110\11b. I ~ O Wc. l(H)Wd 600W13. Co nsider lhc lb llowing Slat.cments:Ourrng an ckclron transilion acwss tl1eeowrgy in GaA,, lisI momen1urn ch;ongcsl . di11:ction or ntoHon changes3. pokntinl ene.rg.y changes4. kinetic energy remains constantWhich of hese Stalemrnt> nrc corrc c(la. J and 4b. 2nnd 3c. I and 2d. I nnd414. March List I (Scmo co nducror property)w1th Lost Ll (Type of semiconductor) andselect !he correct answerList IA. P.lcc tron mohlltty of0. 13 vB. p-typcC. IH)'pcD. Wide band gapI isr III Gennar11um doped wiOo w-sunic2. Gallium arsenide3. Silicon4. Gallium doped siliconCodes: A B C IJa. 3 2 Ib. 4 J 1 23 4 I 2d. 4 J 215. l"hc IIall cocl'lkicnt ul' a snmplc


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17

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,1. suicide and cordlerite17. Uquid cyst:al matemal is used in ultrasonic omplification ond displaydcvic.sb. t h e m ~ a l sensors and tr3nsclucon;c. display c c : s and tbormal sensorsd. transducers 3nd ultrasonic

amplill"'ltiqni\latch l. ist I ( S e ! n i c ~ m d c w ) lA ith Lit 11Cfland gap m \1 ) 01111. sdc:ct th t .:OITl'"Cl" c t ' ~List lII. GaAsa. lnPc. [ n l _ j - ; ~ A s

D, GoAl.o\JIList IL I.H2. 1.433. 1.354. 0,75C Q d c . ; A 2b. 2" .d. 3

133322

ll"'ertion (r\):coslllnt

c D1 .j.4 l4 II 4n rein ive dielectnc

Reason (R.): With int re.,se ;,, ! ' r e q u e u e ol'th" applied li cld. tl1c Jilll31izntiunproces!ies i n t . T C ~ Q l e in number.a. Both A and R are. tn>e and R .- lheconect explamLion of Ah. Doth 1\ and R ate ll'uo hut R i. NO Tthe cum:cl n n t i o n n l ' Ac. II is tn1a but R Lfalad. A is false but R is trueAssertion (AI: lnasemiconductor. th.11'0 lluu u11d R i.s tbc

correct c:.xpJ!tnntiuu ofAb. Both A and R are true but R is NOTthe correct e.xplana tion of Ac. A is true but R is falset l 1\ il< false but R i. true.l\ssertion (A): The mcasUJ 'C':ruenl ofimpedance by bridge method L> moreaccurale th11n the direct method usingindicaling ln! truments.Re-J.Son (R); Tite uccw'llc)' of lite dt!teclOIdO'; not affect Ue occuracy ofnie;tS false bulk is tn1eAssertion (AJ: Eleclric field cannot exist

l n s i d ~ o pfcct .:oncluolor.Rcoso11 (R): For pc11i:ct "onduclUJ' 11 ' "and thc>r. ond R = lruc but R ;, NOT

1he correct c.xpl:motion of \c. A is tnre bnt R is falsed. A false but R is tn>e

A o ; s ~ : ~ t i (A); ln current-corryingcylindrical ~ t > n d u . n o r . U1o maguetic tieldinlensltv within the conductor in.:rease!'l l n e o r l ~ wilh rudla l dist:mce.


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Reason The enclosed cunemIncreases as the square of the mdialclisrance while the perimeter increases onlyas the radial distance.a. Both A and R are true 3nd R is thecorrect explana tion of Ah. Both A and R are tnte but R is NOT

the con'ect cplanution ol' Ac. A is true but R is flllsed. II is false but R is trueAssertion (A): An unstable control systempossesses at lea


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c 100 V :md 200 V/s


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c. the co nnection elegantd. the pQWer f(\ctor correct ion more.effectiveA three-phase healing unit uml indu ct ionmotor are conneded in parullel ncrQss a208 V t h ~ e - p h a s e supply. Moto r is rotedat 5 hp. 0.9 pf witl1 efficiency of 0.85.Heating un it is ra ted ot 150'lcc. compensation theoremd. cquivalcntthcorcmA vo huge v(l) = 6 e-1> is applied ut t =0 toa series R - L circuit with l = Ill. If 1(1) =(21) - cxp ( 3t) then R will have. avalue ofa. 2/3 no. ' nc. 3 0d. 1/3 nIn the circuit shown, the S\lltch is openedat t = 0, Prior to tharswitc.h was dosed, i(t)at t o is

Swtt:b' [ , . '20 10"'~ ' 1a. 2!3Ab. 3121\c. I/3Ad. lAConsider the mllowing l a t ~ m e n t srcgardihg the circuit shl}wn in the figure. Ifthe power consumed by5 n is I0 W. thent. I'I=E f2. [he total impedanceof the circuit is 5W3. c o s ~ = 0.866

6o lifo~ ~ N v - - - - + - - - ~ ~

- - - ~ - - - 0 - - JWhich oflbese statements are correct'!a. I and 3b. 2 and 3c, I and2tl. I, .h nd 3In the network o w in the given figurethe Thevcnin source and the in1pedanreacross tenn iunls A - B willrespeclivel}


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100 10050cp IDA.

L - - - - - - - ~ - - - - - - - - 8a. J5V und JJ.33 nb. 50 V und IH lc. 11 5 Vand200J. 100 v and 25 nf'or the lune.tionr-P 3s+ 1;;z, [f(t)) z { . + 4s + 5)

. 3h. 113c. Zerod. 2t3

df \ dr 1 .

Anurc ;;ource 01'200 V rms supplies activepower uf600 \V ond rcactive po"" 'of 800VAR . Ihe nus curTcnt dntwn liorusourCe isa. 10 Ah. SAc. 3.75 Ad. 2.5 AIn the given 2-rort ncl\\ork. if the dri,ingpo inr (d. p.) impednnce ot J>Orl I., ( ) ,. (.v +2) h d . . .6 11 N -=- 1 \ 1- ( .- l e \ p. tmpl.;--uance HS+ ) )

port w II l>c

~ : ~ i--,7 ( )- , . (s+3)u. h lJ _,...._ , -( ).v+5. (.


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A 13 c 0a, 3 4 I 2b. 3 4 2 Ic. 'J 1 Id. 4 3 I 2luthc SJsystem, tbe dimension ofemf is M 13T 1 1h. ML1T -' r 1c. M l 1 T ; r 'd. M' ' eT ' IWhich nne of Ihe f'ulh\wing techniques iadopted to reduce the sell'-induCllJlce of a

w i r c . ~ - w o u u d sutudard resistor?a. Bililnr \vindinl:lb. N c g a t impcdanco convenerc. P o r ~ e balance lype 1'1111< co!llpensutiond. Providiug additional potential

tcrminutsThe voltageofu standard ce ll is monitoreddaily over a period or one ycar4 (be tut-nnvalue of the voltage for every anonll1shows o standard devimion o fO . I mV.standard deviation oflhe set constiwted bythe month ly mean values will hea. zeroh. 0.1/ 12c. 0.11 .[12d. 0.11 bridge ~ w n in the given fi!!,Ufe, Ifthe oes istance R, is increased from 1 kQ to1.5 k02. the current l1 \Viii

; r . ~ ~ ~~ : 2 - - .... // ..

a. increa.sc-b. decreasec. nol chungud. increase or decrease depeood itg on thepolurity of I!A de electronic volhlleter using chopperswbilizatiou is free fro111 ermrs due toa. low CM RRh. amplifier orit\o, ~ o u r c e output i111ptda1tced. in terference

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Hof 15In a Pl\ILMC instrument. the cemral springstiOhcss and the strenglll of the magnetdecrea;;e b) 0 . 0 ~ % arid 0.02% r e s p e e ~due to a rise io1 tempernture by Ic. With ol'ise in temperature of Ioc. the iostrumentreading wiUa. increaseby 0.2%b. decrease by 0.2%c. increase by 0.6%d. dc"rcaseby 0.6%When a current i(t) = 5 + 10 C < l ~ 314 t ismeasured by ;m electrodynamics ammeter,!Joe mctc.rwi ll reada. Js> 1ob. (f )_(lo)'l

d. rrwo equal vohages (1( same frt:qucncyapplied to the X and Y plates 11ra CRO.produce a circle 011 the screen. The phasedifference between the two voltages lsa. 30h. 60c. 90d. 150In a Q-meter. un inductor tunes to 2 MHzwith 450 pF and to 4 MI-la with 90pF Thedistributed capacitance ofthc Inductor isa, 30 pPb. 45 pi 'c. I)() pid. 360 pFConsider the nelwork shown In the givenfigure. ifn voltmeter of internal resistoneeI0 kO reods V1 ami V respectively whenconnected stn:ss 5 kn nod I() kf l in t11 rn ,then

..vrlu . ,IOl!U

a. v, > V,/Jb. V, < V22c. v1=v,t:.


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d. V1 c 6.67 VConsider the following w t c m c n ~ A cwrent tnmsformer. is used lo rt ll eU$Ufell1Ctl t O f ~ CUfTllll[$ 101. Isolate the instrument lrom a hi9hvoltage bus t>ar.:!. increu.se the accurnc) ofmeasu1em en13. decrease the cos t of measuringamlngcmcntsextend range of measurement of ucunvcn tionnl 3mnlcterun ucWhich of l1esestmem.:nts are correct'/a, I and 2b. 2and3c. 3 and4d. I ood 4li'IJ1e reudings f l l t two wuu


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and C. Tlle pnir -'1 - B gives an emf ofll>5 f!V, wi th Ute end of A ~ positive.l'hc pai r B - C gives I()() ' 'V. wi th the endof C' being positive. The pa ir A - C willgivea. 265 flV wi th the end of i\ beingpositiveb. 265 ,,v wi th the end of (" beingpos-irivec, 65 )JV with lhe end vfA ooing positivrd. 65 !JVwith the end ofC being positiveCousidC gaiu isreduced b) 10% in each system. then thevariation In C1 and C will oo respectively1

f ' igw-.l

1 - ~ r = = - c.Figurt f l

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a. IU% and 10%b. 2%and 10%c. 5%and 1%tl. 0 and 1%

111 or 15

The block diagrams shown in 11gurc-l andfigure II a"" equivalent ifx (in ligurc-LI)is equal toR(s) .j.--7--::-,....,i' II--Cs)

F tgllrt! I

Pi.gurt lla.b. 2c. S ld. S l1Po r the system shown in the given tigurc.the stendy-state value or he output c( t) is

lNPtl't ,._ Uah. ~ . e p

a. 0b.c. ~d. dependent on the va lues of K and K1The signal flow b'Tt>ph shown in the givenfigure has

a. three forward paths and 1wo nontouching loopsb. thr


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"'''

a. (s+10)10b. s(s+10)10c. 10s+lOd. 10s(s +10)

84-. The Bode plot s h o ' ' ~ Tn the given figurehus G ( j ~ l ) as...... 1 1 , 1 ~. ..... . ~ 10 ~ ~ " " -

IOD -.. ..

-1111AIIoliw.oll

100a. jro (I+ jU.5ro ){ I+ j UI ll)b. 100j ) ( I O + jto )

f ()c. ( l + ~ J +IUjw)d.

10jw(I+ 0.5/& ( I+O.IJm)

85 . The polar J ; ~ l o t of G ( ) = ~ -1-'Is for() :s"' s oa in G-plane isa.

C't-i!larlc- h.

~ 5..c. ~ 0d.

0 -.plaue',._ p:O

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II urt5The unit impu lse responsu oru lint!at timc."-1nvarkmt second-order syslem isg(t) = Joesin61 (1 ~ o)'llle nantrdl e q u c and the dampingfactor of he system arc respectively" ' IU ratlls and 0.6h. I0 rad/s and 0.8c. 6 rad/s and 0.6d. 6 ratlls and 0,8Malch List I (Rnou; in U1e s plane) withlist U (Impulse response) and select thecorn.""C[ ru1swer:Lis1 IA. A single roo t at the originJ:l. II single root on tbe negative real "''isC. Two imaginary rootsD. Two complex roots in the. right hal f

planeList Tl1.

h ( t ) ~

""'lt= .$ lJ.

ht l 'L. ._,4.

b ( t ) ~5.

Codes: II B C D~ 2 1 5 4b. J 2 4 5c. J 2 5 4d. 2 4 5The root-locus or a un ity lc tdback syskmis shown In lhe given l i g u r ~ . The openloop transler lt tnclion nl'thc system islol


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a. A"1)(..-+J)b. A:(,


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;;+ 2y + s;, +6y ; 5 ~If sm1e variables are x1= y. "'' = y and .x; =y, Ihen 1hc cocmci.,nt ma1rix 'II' wil l iJ


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1-cxp(- 1)Z - exp( - I)

b. z [ l+exp(-1)](2 - t)[Z +exp(-1)]

c. I +-


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a. Pow.:rb. power densityc. e r g yd. energy density

I I I. The quationt : a, sin ( lJt - flt )+a,.Esin(IIJ/- fh)representsa. u circulnrly pIarized wave112_ n te lnLriiiSIC m p a n c ~ of free space ISa. 3770h. Jll .e..C, j JJ.I.,Cod &,, I11 .

11 3. Consider tho J{lllowmg pairs of t)'llcs ofencrg) transmtssion und practical lowerfr..:quency 1imit:I. "I n l l ~ m t S s i o lines- Lero2 Optical fibres ... JO() Mllz3. A nrcnnas.. .. I 00 MllzWhich of these pair(s) isfare Lwrcctlymatched'!a 2 and Jb. I and 2c. I aloned. J W{li!C

11 4, If the electric fidd compoocnt vfa w11vC isI' = cos 16 H)' xt +51lz) a, VIm, then thewavea. p m p ~ ~ g a t e s in -x dfrccttonb. amplitude is -./2 VImc, is not tnfVcling in free spaced. propngntcs in + z dirccuon

11 5 A plane clcctromagnctk wave is travellingin a h i g h dissi pative medium indirection ABC as $hOwn In the figure. Thoelectric tk ld EA. Eo. and Ec at point A. 13nn_!l C respec t.hely are retmed asA B C1- d - < ! < ~ t o - - -EA t o ; , ~a E' -E '' ' t - ,

b E , L"'' I ;,: .!;,C, _,,. =d. _, . = (.

II (o, Cavity resona tors nre used ina. MF bondb. II fl bondc. VHf bandd SHF hand

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I17. Tile renectlm C O t ' n l t t i ~ n t at the I

ies electrical engineering paper 1 1999

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