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END SEMESTER EXAMINATION

Total No. ofPages 4SECOND SEMESTER

RoUNo .B.E. (COE/EC/EE/IC )

M!llY-2009COE/EC/EE/ IC-ll1 PRINCIPLES OF

ELECTRICAL ENGINEERINGMax. Marks: 70

I Giving reasons (briefly) explain why?[a] Capacitor and inductors are considered as wattless components.[b] Current/voltage and power can not be expressed on the same phasordiagram.[c] Voltage sources are short circuited and current source open circuitedn's of

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A magnetic circuit of cast iron having the configuration anddimensions shown in Fig. below has cross sectional area of 0.005m'through out and an air gap of 0.002 m. Find the mmf required to beproduced by the coil in order to establish a flux of 4xlO'" Wb in the airgap. 8Length aefd =0.25m eLength (ab+cd) =0.248 r- - - - p, - '- - ,,Length (be) =0.002mLength (ad) =0.15mMa netic characteristics of cast ironB 0.08 0.38 0.46H 190 1163.5 1400 --

[b] The circuit shown in the figure given below is operating in thesinusoidal steady state. Device I absorbs 360 W with :unity p.f.,Device 2 absorbs 1440 W with a p.fo fO.8Iagging . Find the value ofthe capacitor C so that the magnitude of the source current equals IS Anns. What is the power factor of the two-device-capacitorcombination? 5

[c] A coil of resistance 'R' and inductance 'L' is shunted by a capacitor C.Derive the expression for frequency at resonance condition. . Show thatat parallel resonance the effective impedance seen by source is LlCRand the circulating current in capacitor is V ~ for small resistance.

55[a] A 3-phase motor takes 10 kVA at 0.6 pf lagging from a source of220V, 50 Hz. It is in parallel with a balanced delta load havingimpedance of 16-j 120 in each phase. Find the total volt amperes,power, line current and power factor of the combination. 8[b] With the help of phasor diagram and mathematical analysis show thatactive and reactive power in three phase circuit can be obtained by twowattmeters. Draw a neat diagram of the circuits with wattmeterconnections properly labeled. 6

6[a]

S(Jt1.f2.. 2Soon.. ~o ,o :>lv,

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Using principle of Superposition determine the current ' i ' in the circuitshown in the figure given below. 8o/' .

[b] A circuit having VI characteristics as shown in Fig. below has to bemodeled as Thevenin's and Norton's equivalent form, Compute thevalues and draw the equivalent circuit thus obtained. 4

[c] Derive the expressions for equivalent delta connection parameters ofstarconnected circuit. 5

[b] For the circuit s"hown in the figure given below v, = 10.J2 cos(1000/) .Find the values of the resistance RL(in 0 ) and the capacitance C (inmF) such that the maximum average power is 'absorbed by the load.

6

3[a]

4[a] Calculate the voltage across the 10 resistance shown in the figuregiven below. 4

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[b] Discuss the magnetization characteristics of ferromagnetic material.Draw a neat diagram depicting hysteresis loop, and label the diagramappropriately. Explain why the point of operation is generally kept atthe knee of the magnesation characteristics. 4[c] The magnetic circuit shown in the figure given below having samecross sectional area and magnetic material is symmetric about itscentral limb. Each limb is wound with coils of same number of turnsand have same excitation current. Explain' why the central limb hasmore concentration of flux.

~ j ; - ~, b- -- p , 2

7[a] A current i(t) is passed through a moving coil and moving ironammeter connected in series. Compute the readings of the instrumentswhen i(t) is

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Roll No. ... ...B.E. (COE/EC/EE/IC)

END SEMESTER EXAMINATION M9lY-2009COE/EC/EE/IC-112 APPLIED MECHANICS

Time: 3 Hours Max. Marks : 70

1[a] Differen tiate between1. Torsional Rigidity and Flexural Rigidityu. Selflocking machines and Irreversible machinesl l l . Frame and StructuresIV . Strength and Toughnessv. Redundant and Deficient trussvi. Kinematics and Kineticsvii. Stat ic & kinetic Friction Ix?

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[b] Determine the Moment of Inertia of the shaded area with respec t to xand y axis, when a = 20 mm. 7

j3[a] Compute the moment about A of the force shown and veri fy it by

solving it by Varignon's method . (i) by resolving the force intohorizontal and ve rt ica l directions (ii) by resolving the force intocomponents along AB and perpendicularto AB. 7

t[b] Knowing that a = 45 replace the 600 N force by (a) an equivalent

fo rce couple system at C, (b) an equivalent system formed by twoparallel force s at Band C. 7

4[a] The position of the machine block B is adjus ted by mov ing the wedgeA. Know ing that the coe fficient of static friction is 0.35 between allthe surface of contact, determine the force P required to (i) raise (ii) tolower the block . 7

[b] Determine the forces m members CD and DF of the truss shownbelow. 7

5[a] A bar of 25 mm diameter is subjected to a pull of 40 kN. Themeasured extens ion on gauge length of 200 m is 0.085 mm and thechange in diameter is 0.003 mm. Calculate the value of all the Elasticconstants. 7

[b] A tensile load of 50 kN is act ing on the rod of 50 mm diameter andlength of 5 meter. Determine the length of a bore of 25 mm that can bemade central in the rod if the total extension is not to exceed by 25%under the same tensile load. 7

6[a] The moment of Inertia of a beam sect ion 500 mm deep is 69.49 x 107mm" Find the longest span over which a beam of this section whensimply supported could carry a uni formly distributed load of 50 kN permeter run . The stress in the material is not to exceed 110Nzmm",

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[b] A steel shaft transmits a 105 kW at 160 rpm. If the shaft is 100 mmdiameter, find the torque on the shaft and the maximum shear stressinduced. Find also the twist of the shaft in a length of 6 meters. TakeG =8 x 10' N/mm2 7

7[a] A beam AB 10 meters long has supports at it' s ends A and B. It carriesa point load of 5 kN at 3 meters from A and a point load of 5 kN at 7meters from A and a uniformly distributed load of I kN per metrebetween the point loads. Draw SFD and BMD for the beam. 7[b] A cantilever of length 2 meters carries a uniformly distributed load of2500 N per meter for a length of 1.25 meters from the fixed end and apoint load of 1000N at the free end. If the section is rectangular 120mm wide and 240 mm deep, find the deflection at the free end. TakeE = 10000 N/mm2 7

8[a] At a point in an elastic material under strain there are normal stressesof 60 N/mm' and 40N/mm' (both tensile) respectively at right angle toeach other with positive shearing stress of 20 N/mm' . Find the (i) the

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, Total No. ofPagers): 2 Roll No .SECOND SEMESTER s.s, (COE/ECE/EE/ICEjR E. END SEM. EXAMINATION, May 2009COE/EC/EE/IC-113 : MATHEMATICS - II

Time: 3:00 Hrs. Max. Marks: 70Note: Answer all questions s electing two parts from each one.All questions carry equal marks.1. [a]

il I f B= sin - I ,f; + Jy' then prove thatx+ y,a'B 2 a'B z a'B sinBcos2Bx ax2 + xy ax0' + y 0'2 = 4cos3Biii Find du if u =sin(x' + y ' ~ where a'x' + b2y ' =c'.dx

[hJ Expand x'y+3y -2 in powers of (x - I ) and (y +2) byusing Taylor 's theorem.[e) Examine the function

sinx+ siny +sin(x+ y)

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a ua e axayaz over m e po sn~ 1 _ x _ y2 _ Z2tant of the sphere x 2+ y2 + Z2 = I.ange the order of integration in the integralfa t'-y' xy dx dyd hence evaluate

d 4Ive --?- y = cosx cos hx .fixIve the system of equ a tions :dx- +4x+ 3y =tdt

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END SEMESTER EXAMINATION

Roll No .B.E. (COE/ IC)

! M ~ Y - 2 0 0 9COE/IC-114 INTRODUCTION TO PROGRAMMING

Tillie: 3 Hours Max. Marks : 70Note: Question No. ONE is compulsory.Answer any FOUR questions from the rema ining.Assume suitable miss ina data, if anv.1[a] Give different type of memory present in computer system and their

purpose. 4[b] What is the function o f con trol unit in computer system. 2[c] What is the purpose of operating system. What ISmultitask ing/mu ltiprocessing. Give three examples of these operating

system. 4

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3['1] Eva luate the value of following logical expressions showing order ofprecedence for a = 5, b = 10 and c = -6(i) a >b&& a 15 && c < 0 II a > 0(iii) '1 = =c IIb > a(iv) (a/2.0 = 0.0 && b/2.0 I = 0.0) II c < 0.0(v) (a%3.0! = b%2.0 IIb/2.0 = = 1.0) 5[b] (i) Subtract (01001)2 from (10111)2using 2' s complement.(i i) Solve the hexadecimal expression 0.6Ax163 - 0.9Bx162(iii) Divide (76032), by (321),(iv) Convert (3762), into Excess-3 code. 8

4 Answer the following questions to the point:[a] What are the charact eristics of good programming? 2[b] What is the difference between an interpreter and a comp iler? 2[c] What is top down programming? How it is different from bottom-up

programming approach? 3[d] What is a functio n? What is function prototyp e? What are the rules offunction declaration? 4

[c] Differentiate between : (i) Global and local variable (ii) Auto andStatic variab le. 2

5[a] Write a C program to read and print the string"WORD PROCESSING" . 5

[b] Write a program using 'C' language fo r extracting characters fromabove string starting from jlh position to jlh position where i and j areinput from the user. 8

6[a] Define a structure called cricket that will describe the information :-player name, team name, batting average,

using cricket, declare an array playe r with 50 element s and write a ' C'program to read the information about all the 50 players and print ateam-wise list containing the names of players with their battingaverage. 8

[b] Write a program to copy contents of one file into another file. State thevar ious modes of opening a fi le. 5

7['1] In what way a switch statement differ from the if statement in 'C 'language. 2

[b] Write down a switch statement to calcu late number of days in differentmonth of the year where value of yea r is being input. 5[c] Write down a program in 'C' language which input 100 natural

numbers and print them with the label as odd/even. 68[a] Write a 'C' function that will round a float ing point number upto the

indicated decimal place. Use this function in the main program to sumup two floating point numbers which are input and print the sum indecima l form upto 3 digits. 8

[b] What is recursion? Write down a recursive 'C ' function to evalua te theFibonacc i sequence upto n terms. 5

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Roll No .B.E. (COE/IC)

END SEMESTER EXAMINATION 'lvtfllY-2009COE/IC-llS PHYSICS OF MATERIALS

Max. Marks: 70illie: 3 HoursNote : : Question No. ONE is ,compulsorY. ;', . '',, ", " A n ~ w e r any FOUR q u e s i o i l s r o m i ~ e r ~ m a i n gAssume suitable missin data, if an .I[a] What do you mean by 'wave packet' ? Expla in III the context of

uncertainty princip le.[b] What are Miller indices? Find the Mille r indices of a plane in anorthorhombic unit cell (a:b:c =1:2:3) making intercepts of 3,2, 1 on a, band c axes respectively.

[c] What do you mean by Fermi level and Ferm i temperature. Discuss the

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[b] Explain giving necessary background how room temperaturesuperconductor, whenever available, will help in faster transport andfaster computer. 3[c] The values of T, and H,o for lead is 7.18 K and 6.5 N m respectively.Calculate the critical current density for I mrn diameter lead wire at 4.2K. 33[a] Define 'polarization' for a dielectric material. Name and briefly

explain various types of polarization. 5[b] What are 'p iezoelectric' materials? Why some crystals showpiezoelectricity? Mention various applications of piezoelectricmaterials. 4[c] What are electrets? How are they prepared? Mention the uses ofelectrets. 2[d] Polystere has a relative permittivity of 2.5 when subjected to a d.c.electric field. Find the polarization in it when a potential difference of100Y is applied across a 0.5 mm thick sheet. 34[a] Define (i) relative permeability, (ii) gyromagnetic ratio (iii)magnetization and (iv) magnetic ' susceptibility. Classify magneticmaterials on the basis of the susceptibility values. 5[b] Draw the B-H curve for a magnetic material and explain it usingdomain theory. What informations can be derived from the B-H curveabout the applications of a magnetic material? Discuss and hencedifferentiate between soft and hard magnetic materials. 5[c] A magnetic material has a magnetizationB uoAzm and flux density of

0.0044Wb/m2. Calculate the magnetizing field and the relativepermeability of the material. 4

[b] Discuss the sources of resistance in metals and their variation withtemperature. 3[c] The Fermi energy of silver is 5.5IeY. (i) What is the average energy of 'the free electrons in silver at OK? (ii) What temperature is necessaryfor the average molecular energy in an ideal gas to have this value?(iii) what is the speed of the electron with this energy? 6,7[a] Name different types of bonds in crystals and give their characteristicfeatures. 5[b] Show (101), (110) and (I I I ) planes using a neat and clear diagram.3[c] Show that the potential energy of two particles in the stable

configuration is - 4 ( a)for m =2 and n =10, where the symbols have5 Y,their usual meanings. 6

8[a] Explain the terms: (i) matter waves and (ii) degeneracy. 3[b] Using Scherodinger equation show that the eigen function of a partieleconfined in a one-dimensional box is given byV/" = sin ny-

where the symbols have their usual meanings. Show the variation forn=I , 2 and 3. Also, show that the probability density is maximum ata 3a d 5a I h . . f I I= . , ' " an _. p ot t e vananon 0 V/" for n = I, 2 and 3 82n 2n 2n .[c] An electron is found to move with a velocity of 4 xlO mls accurate to0.01%. Calculate the uncertainity in locating its position . 3

5[a] Briefly discuss the generation and recombination of charge carriers inasemiconductor. Hence define ' lifetime' of a charge carrier in asemiconductor. 3[b] Name and discuss the two mechanism of charge flow in asemiconducting crystal. Hence obtain Einstein's relation. 8[c] The minority carrier lifetime in a p-type material is 10'\ . If themobility of the electron is 0.15 m2y ' s'] at 300 K, calculate thediffusion length of the electron. 3

Constants : kB=1.38 X 10'23J/Ke = 1.6 x 10,19Ch = 6.64 X 10'34Jsm, = 9,lxlO,31kg.

6[a] Discuss the main features of free electron theory of metals.mention its drawbacks.Also,5www.nsitonline.in

coe-09-2nd sem

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