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Code No: V3102/R07 Set No. 1

III B.Tech I Semester Supplementary Examinations, May 2010STRUCTURAL ANALYSIS-II

(Civil Engineering)Time: 3 hours Max Marks: 80

Answer any FIVE QuestionsAll Questions carry equal marks

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1. A parabolic arch hinged at the springings and crown has a span of 20 m. Thecentral rise of the arch is 4 m. It is loaded with a uniformly distributed load ofintensity 2 kN/m on the left 8 m length. Calculate

(a) the direction and magnitude of reaction at the hinges,

(b) bending moment, normal thrust and shear at 4m and 15m from left end. [16]

2. A two hinged parabolic arch of span L has central rise of one-fourth of the span.Show that the horizontal thrust on the arch due to a point load of W at its quarterspan is 5W/8. Take I = Io Sec θ.

3. Explain the Portal method for analyzing a building frame subjected to horizontalforces. [16]

4. A horizontal beam ABCD, is carried on hinged supports and is continuous overthree equal spans each of 3 m. All the supports are initially at the same level. Thefirst span is loaded with central point load of 8 kN, second span is loaded with aUDL of intensity 2 kN/m and the third span is loaded with a point load of 9 kNacting 2 m from right support. Using the slope deflection method, plot the bendingmoment diagram, if the support A settles by 10 mm, B settles by 30 mm and Csettles by 20 mm. Take I = 2.4× 106mm4 and E= 2 ×105N/mm2. [16]

5. (a) Define the term “CARRY OVER FACTOR”.

(b) Explain the term “Distribution Factor”.

(c) Derive the relation for the stiffness factor for a beam S.S at its both ends.[3+3+10]

6. Analyse the continuous beam shown in figure 6 by Kani’s method and draw BMD.[16]

Figure 6

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7. Analyse the continuous beam shown in figure 7using Flexibility method Sketch theBMD & SFD. EI is constant. [16]

Figure 7

8. By the matrix displacement method analyse the beam shown in figure 8 for a 15mmsettlement of the support at B. [16]

Figure 8

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1. A parabolic arch rib, 20 m span and 3 m rise is hinged at the abutments and thecrown and carries a point load of 10 kN at 7.5 m from the left hand hinge. Calculatethe horizontal thrust and the bending moment at a section 7.5 m form right handhinge. What is the value of the greatest bending moment in the arch, and wheredoes it occur? [16]

2. A parabolic arch, hinged at the ends has a span 30 m and rise 5 m. A concentratedload of 12 kN acts at 10 m from the left hinge. The second moment of area variesas the secant of the slope of the rib axis. Calculate

(a) the horizontal thrust and the reactions at the hinges,

(b) the maximum bending moment anywhere on the arch. [16]

3. Analyse the frame shown in figure 3, by Cantilever method. Assume that all thecolumns have equal area of cross-section for the purpose of analysis. [16]

Figure 3

4. A continuous beam ABCD, 12 m long, is fixed at A and D. The first span of length5 m is loaded with a central point load of 8 kN, the second span of length 3 m isloaded with a UDL of intensity 4 kN/m and the third span is loaded with a centralpoint load of 6 kN. Using the slope deflection method, plot the bending momentdiagram, if the support B settles by 30 mm (down) and C settles by 20 mm (down).Take I= 38.2× 106

mm4 and E= 2×105 N/mm

2. [16]




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6. Explain Kani’s method for frames with side sway. [16]

7. Determine the bending moments at supports B and C of the continuous beamshown in figure 7, using these moments as the redundants M1 and M2 respectively.Assume that the redundants are positive when they produce compression on thetop of the beam. EI= constant.

Figure 7

8. Analyse the structure using stiffness method. EI= constant. (figure 8) [16]

Figure 8

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1. A parabolic arch hinged at the springings and crown has a span of 20 m. Thecentral rise of the arch is 4 m. It is loaded with a uniformly distributed load ofintensity 2 kN/m on the left 8 m length. Calculate

(a) the direction and magnitude of reaction at the hinges,

(b) bending moment, normal thrust and shear at 4m and 15m from left end. [16]

2. A parabolic arch, hinged at the ends has a span 30 m and rise 5 m. A concentratedload of 12 kN acts at 10 m from the left hinge. The second moment of area variesas the secant of the slope of the rib axis. Calculate

(a) the horizontal thrust and the reactions at the hinges,

(b) the maximum bending moment anywhere on the arch. [16]


4. A horizontal beam ABCD, is carried on hinged supports and is continuous overthree equal spans each of 3 m. All the supports are initially at the same level. Thefirst span is loaded with central point load of 8 kN, second span is loaded with aUDL of intensity 2 kN/m and the third span is loaded with a point load of 9 kNacting 2 m from right support. Using the slope deflection method, plot the bendingmoment diagram, if the support A settles by 10 mm, B settles by 30 mm and Csettles by 20 mm. Take I = 2.4× 106mm4 and E= 2 ×105N/mm2. [16]

5. By using moment distribution method, determine the support moments at all thejoints of the Portal frame shown in figure 5.

Figure 5

6. Analyse the Continuous beam shown in figure 6 using kani’s method and drawBMD. [16]

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Figure 6

7. Analyse the continuous beam shown in figure 7 assuming that it rests on unyieldingsupports. The fixed end moment at A & the vertical reaction of the support at Bmay be treated as redundants.EI is constant. [16]

Figure 7

8. Analyse the structure using stiffness method. EI= constant. (figure 8) [16]

Figure 8

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1. A three-hinged parabolic arch hinged at the supports and at the crown has a spanof 24 m and a central rise of 4 m. It carries a concentrated load of 50 kN at 18 mfrom left support and a uniformly distributed load of 30 kN/m over the left halfportion. Determine the moment, thrust and radial shear at a section 6 m from theleft support. [16]

2. A two-hinged parabolic arch has a span 10 m and rise 1 m. It subjected twoconcentrated loads of 60 kN at 3 m from the left hinge and 80 kN acts at its crown.Assume that I = Ic Sec θ and Cos θ=1. Take area of cross section at the crown.AC = 0.18 m

2 and E = 15×106 kN/m2. Determine the reduction in the horizontalthrust in the arch due to rib shortening effect. [16]


4. A continuous beam ABCD, 16 m long, is simply supported at A and D. The firstspan of length 6 m is loaded with a point load of 8 kN acting 2 m from left support,the second span of length 5 m is loaded with a UDL of intensity 2 kN/m and thethird span is loaded with a point load of 6 kN acting 3 m from right support. Usingthe slope deflection method, calculate the moments at the support. [16]




6. Explain the rotation contribution method for the frames with columns of equalheight and subjected to vertical loads only with fixed ends and also hinged ends.

[16]

7. Define the term “Flexibility” and draw BMD for the beam shown in figure 7 byusing flexibility method. EI is constant. [16]

Figure 7

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8. Analyse continuous beam shown in figure 8 using stiffness method. Draw BMD.Given AB=BC=10m. [16]

Figure 8

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III B.Tech I Semester Supplementary Examinations, May 2010ELECTRICAL MACHINES-III

(Electrical & Electronic Engineering)Time: 3 hours Max Marks: 80


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1. (a) Explain the construction and working principle of alternators with a neatdiagram..

(b) A 4 pole, 3-Φ, 50 Hz, star connected alternator has 60 slots with 4 conductorsper slot. Coils are short pitched by 3 slots. If the phase spread is 60o, find theline voltage induced for a flux per pole of 0.0943 wb distributed sinusoidaly inspace. All the turns in phase are in series. [8+8]

2. (a) Explain how the synchronous reactance will change at varying load, (as ca-pacitive, resistive & inductive loads).

(b) The SC, OC & DC test data (line) for a star connected 200 kVA, 480 V, 60Hz, are:

VOC = 480 V, ISC = 209.9 A - - - - For same field currentVDC = 91.9 V, IDC = 72.8 A

Determine: Synchronous reactance. [8+8]

3. (a) Compare the ‘Potier triangle method’ method and ‘MMF’ method of findingvoltage regulation of an alternator.

(b) The following test results are obtained on 6600 V, 100 Amp alternator: [8+8]If 16 25 37.5 50 70

EOL-kV 3.1 4.9 6.6 7.5 8.3(where EOL is the line voltage at no load)

The short circuit test yielded full load current at a field current of 20 A, thearmature resistance is negligible. Calculate the voltage regulation at full load0.866 pf leading by MMF method.

4. Two alternators are sharing a load of 2.5 MW at 0.8 pf lagging. Machine 1 has ano-load frequency of 51.5 Hz and frequency drop of 1Hz/MW. The second machinehas no load frequency of 51 Hz and frequency drop of 1 Hz/MW.

(a) At what frequency is the system operating and how much load is supplied byeach machine?

(b) Load is increased by 1 MW. Find the new frequency and load sharing.

(c) The governor set points of machine 2 are increased by 0.5 Hz. Find the newfrequency and load sharing for the total load of 3.5 MW. [6+5+5]

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5. (a) A sub-station operating at full load of 1200 kVA supplies a load at 0.7 powerfactor lagging. Calculate the permissible additional load at this power factorand the rating of synchronous condenser to raise the substation power to 0.9lagging.

(b) Derive the expression for the maximum power developed by a synchronousmotor. [8+8]

6. (a) Explain the procedure to plot ‘V curves’ & ‘inverted V’ curves for a givensynchronous machine with help of its circles diagrams.

(b) A 2 pole, 50 Hz, 3-Φ turbo alternator is excited to generate a bus-bar voltage of11 kV on no load. The machine is star connected and the short circuit currentfor this excitation is 1000 A. Calculate the synchronizing power per degreeof mechanical displacement of the rotor and the corresponding synchronizingtorque. [8+8]

7. (a) Why single phase motors are not self starting?

(b) Explain the necessary arrangements made to make single phase Inductionmotor self starting & with neat diagram explain the operations of same. [8+8]

8. (a) List applications of stepper motor & Universal motor.

(b) Explain the construction of AC series motor. [8+8]

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1. (a) Explain the various winding factors? Explain the effects of each of them.

(b) Determine the slot distribution and the pole phase group sequence for a 45slot, 6 pole, 3-Φ winding. [6+10]

2. (a) Explain the sources of harmonics. What are the various effects of harmonicson generated emf in an alternator?

(b) Find the RMS value of fundamental & third harmonic EMF per phase for analternator having following data: 50 Hz, 3-Φ, 20 poles, 4 slots/pole/phase,double layer winding with 6 conductors/slot, coil span of 150o, flux per pole:fundamental is 0.1 wb, third harmonic 17 % of fundamental. All coils of aphase are connected in series. [8+8]

3. (a) What is the synchronous impedance method? Why the method is called so?What are the limitations of this theory?

(b) The following table gives the OCC & SCC of a 2 pole, 11kV, 50 Hz, 3-Φ starconnected alternator. The stator resistance between two terminals is 0.2 Ω.Calculate the regulation at full load current of 125 A at 0.8 pf lagging (bysynchronous impedance method) [6+10]

If 16 20 25 32 45EOL-kV 4.4 5.5 6.6 7.7 8.8

(where EoL is line voltage at no load)

4. (a) A 3-Φ, 11 kV, 10 MW, 50 Hz star connected alternator has synchronous im-pedance of 0.8 +j8 Ω/ph. If the excitation is such that OC voltage is 14 kV,determine:

i. The maximum output of generator

ii. The current & power factor at this output

(b) Explain the terms synchronizing power & synchronizing torque. [10+6]

5. A 3-Φ, 400 V, 40 kVA, 50 Hz, star connected synchronous motor has a synchronousreactance of 4 Ω/ph. Its frictional & windage losses are 1.8 kW and core losses are1.2 kW. The shaft load is 12 kW initially and the power factor of the motor is 0.8leading. Calculate:

(a) the line current, armature current & excitation EMF

(b) Calculate the new values of armature current & motor power factor if the shaftload is increased to 22 kW. Excitation voltage is kept constant. [8+8]

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6. (a) Explain the various starting methods of synchronous motor.

(b) Explain the characteristics of synchronous induction motor. [8+8]

7. Explain the equivalent circuit of single phase Induction motor & give all necessaryequations.

[16]

8. With neat diagram explain the construction & working of variable reluctance step-per motor. Also explain its static & dynamic characteristics. [16]

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1. (a) Explain the differences between stationary armature and rotating armature.What are the advantages of rotating armature over stationary armature?

(b) A 4 pole alternator has an armature with 25 slots and 8 conductors per slotand rotates at 1500 rpm and the flux per pole is 0.05 wb. Calculate the EMFgenerated, if winding factor is 0.96 and all the conductors in a phase are inseries. [8+8]

2. (a) Explain the effect of armature reaction on the EMF induced. Is it possible toobtain load voltage more than EMF induced? if yes, how?

(b) A 200 kVA, 480 V, 50 Hz, star connected synchronous generator with a ratedfield current of 5A was tested and the following data were obtained:

OC test: 540 V between lines on open circuit.SC test: 300 A.

When a DC voltage of 10 V was applied to two of its terminals, a current of25 A was measured, find the value of synchronous impedance, synchronousreactance voltage regulation of 0.6 p.f leading. [8+8]

3. (a) Explain the various tests conducted on an alternator to find the voltage reg-ulation of an alternator by Potier triangle method.

(b) The no load excitation of an alternator required to give rated voltage is 1pu. In a short circuit test with full current flowing in the armature, the fieldexcitation was 0.85 pu. Determine the approximate excitation that will berequired to give full load current at 0.78 PF leading at the rated terminalvoltage. [8+8]

4. (a) Explain the ‘two bright one dark’ & ‘all dark’ method of synchronization ofalternators.

(b) The EMFs of two alternators are 30006 200 & 29006 00 V. Their synchronousimpedances are 2 + j20 Ω/ph & 2.5 + j30 Ω/ph. The load impedance is 10 +j4 Ω/ph. Find the circulating current. [8+8]

5. A 50 Hz, 4 pole star connected SM has a synchronous reactance of 12 Ω/ph andnegligible armature resistance. The excitation is such to give an open circuit voltageof 13.2 kV. The motor is connected to 11.5 kV, 50 Hz supply. What maximum loadcan the motor supply before losing synchronism? What is the corresponding motortorque, line current & power factor? [16]

6. (a) Explain the construction of damper winding. Clearly show the location ofdamper winding.

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(b) With neat diagram & explanation, show how damper winding prevents oscil-lations. [8+8]



8. (a) Explain the working principle of AC series motor.

(b) Explain, why the no load speed of AC series motor is very high? [8+8]

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1. (a) What is short pitch winding & distributed winding? Why the armature wind-ing is distributed & short pitch type?

(b) Calculate the EMF of a 4 pole, 3-Φ, star connected alternator running at 1500r.p.m from the following data: Flux per pole = 0.1 wb, Total number of slots= 48, Conductors per slot (in two layers) = 4, coil span = 150o. [8+8]

2. (a) Explain the effects of harmonics on electrical power system & utility.

(b) Calculate the RMS value of EMF induced per phase of a 10 pole, 3-Φ, 50 Hz,alternator with 2 slots per pole per phase and 4 conductors per slot in twolayers. The coil span is 150o electrical. The flux per pole has a fundamentalcomponent of 0.12 wb & a 20% of third harmonic component. [8+8]

3. (a) Explain the voltage regulation method of an alternator by which the armaturereaction & leakage reactance can be separated.

(b) A 3-Φ, star connected salient pole synchronous generator is driven at a speednear synchronous with the field circuit open and the stator is supplied froma balanced 3-Φ supply. Voltmeter connected across the line gave minimumand maximum readings of 1196 V & 1217 Volts. The line current fluctuatedbetween 120 & 225 Amp. Find the direct and quadrature axis reactances perphase. Neglect armature resistances. [8+8]

4. A 3-Φ star connected cylindrical rotor alternator has synchronous impedance of1 + j10Ω/ph. It is operating at constant voltage pf 6.6 kV and the field currentis adjusted to give an excitation voltage of 6.4 kV. Find power output, armaturecurrent & power factor under the condition of maximum power input. [16]

5. A 3-Φ, 18 MVA, 10 pole, 50 Hz, 11 kV, star connected synchronous motor has ×d

= 5 Ω & Xq=3 Ω. It has negligible armature resistance. Calculate the followingon full load at 0.8 pf leading:

(a) The excitation voltage

(b) Power

(c) Maximum value of power angle and corresponding power. [5+4+7]

6. (a) Explain the various starting methods of synchronous motor.

(b) Explain the characteristics of synchronous induction motor. [8+8]

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8. (a) Explain the construction of permanent magnet stepper motor.

(b) With neat diagram explain the vector diagram of AC series motor. [8+8]

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III B.Tech I Semester Supplementary Examinations, May 2010DESIGN OF MACHINE MEMBERS-I

(Mechanical Engineering)Time: 3 hours Max Marks: 80


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1. (a) Define the terms load, stress and strain. Discuss the various types of stressesand strains.

(b) Explain the difference between linear and lateral strain. [10+6]

2. (a) Explain the following terms:

i. Endurance limit

ii. Size factor

iii. Surface finish factor

iv. Notch sensitivity.

(b) A 50 mm diameter shaft is made from carbon steel having ultimate tensilestrength of 630 Mpa. It is subjected to a torque which fluctuates between2000 N-m to 800 N-m. Using Soderberg method, calculate the factor of safty.Assume suitable values for any other data needed. [8+8]

3. (a) Sketch various types of riveted joints.

(b) A double riveted lap joint with zig-zag riveting is to be designed for 13mmthick plates.Assume σt= 80MPa, τ= 60 Mpa and σc= 120 MPa. [6+10]

4. Determine the size of the bolts and the thickness of the arm for the bracket asshown in the figure 4, if it carries a load of 40 KN at an anlge of 600 to the vertical.The material of the bracket and the bolt is same for which the safe stresses can beassumed as 70,50 and 105 MPa in tension, shear and compression respectively. [16]

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Figure 4

5. (a) Prove that a square key is equally in shear and crushing.

(b) Design knuckle joint for a tie rod of a circular section to sustain maximumpull of 70 kN. The ultimate strength of the material of the rod against tearingis 423 N/mm2. The ultimate tensile and shearing strength of the pin materialare 507 N/mm2 and 395 N/mm2 respectively. The factor of safety is 6.Sketchthe designed joint with dimensions. [4+12]

6. (a) What is the comparison between solid shafts, hollow shafts and spindles.

(b) Compute the diameter of a solid shaft which has to transmit 16kW power at300rpm. Ultimate shear stress per shaft material is 350N/mm2 and factor ofsafety for design is 6. If a hollow shaft replaces the solid shaft, find the insideand outside diameters if the ratio is 0.5. [6+10]

7. Design a cast iron protective type flange coupling to transmit 15kW at 900rpmfrom an electric motor to a compressor. The service factor may be assumed as1.35. The following permissible stresses may be used :Shear stress for shaft, bolt and key material=40MPaCrushing stress for bolt and key=80MPaShear stress for cast iron =8MPaDraw a neat sketch of the coupling. [16]

8. (a) Write short notes on leaf springs

(b) A lift system is provided with cushion springs at the bottom of lift. The lift isfree to fall. Springs are set in parallel. Specify the required number of springsif the lift has free fall of 1.5m from rest.Weight of lift = 30kNAllowable deflection per spring = 370 mmNumber of active turns =15Spring mean coil diameter =30 mm

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Spring wire diameter = 30mmModulus of rigidity for spring =80Gpa. [6+10]

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1. (a) Classify the various types Machine Design.

(b) What is the procedure adopted in the design of Machine elements. [6+10]

2. A hot rolled steel shaft is subjected to a torsional moment that varies from 330N-m clockwise to 110 N-m counter clock wise and an applied bending moment at acritical section varies from 440 N-m to -220 N-m. The shaft is of uniform cross-section and no key is present at the critical section. Determine the required shaftdiameter. The material has an ultimate strength of 550 M N/m2 and a yieldstrength of 410MN/m2. Take the endurance limit as half the ultimate strength,factor of safty of 2, size factor of 0.85 and surface finish factor of 0.62. [16]

3. (a) Show with neat sketches the various ways in which a riveted joint may fail.

(b) Two plates of 16mm thick are joined by a double riveted lap joint. The pitch ofeach row of rivets is 90mm. The rivet are 25mm in diameter. The permissiblestresses are as follows.σt= 140 MPa; τ= 110 MPa; and σc= 240 MPa.. [8+8]

4. (a) Define the following terms with necessary sketch.

i. Major diameter

ii. Minor diameter

iii. Pitch

iv. Lead.

(b) Derive an expression for the maxim load in a bolt. When a bracket with acircular base is bolted to a wall by means of four bolts. [8+8]

5. (a) What are the various types of keys? Discuss their merits and demerits?

(b) Select a key for a 100mm dia shaft transmits 750kW at 1000r.p.m. The allow-able shear stress in the key is 100MPa and the a allowable compressive stressis 200MPa. What type of key should be used if the allowable shear stress is30MPa and the compressive stress is 120 MPa. [8+8]

6. The shaft of an axial flow rotary compressor is subjected to maximum torque of2000N-m and a maximum bending moment of 4000 N-m. The combined shock andfatigue factor in torsion is 1.5 and that in bending is 2. Design the diameter of theshaft, if the shear stress in the shaft is 50MPa. Design a hollow shaft for the abovecompressor taking the ratio of outer diameter to the inner diameter as 2. What isthe percentage saving in material? Also compare the stiffness. [16]

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7. (a) State the difference between coupling and clutch.

(b) Discuss the function and necessity of coupling.

(c) The following specifications are given for a rigid coupling:outer diameter of flanges=160mmdiameter of recess =95mmnumber of bolts=6pre-load of each bolt=10kNcoefficient of friction=0.15speed of rotation=100rpmThe bolts are set in large clearance holes. Calculate the power transmittingcapacity of the coupling. [2+2+12]

8. A semi elliptical laminted spring is to carry of load of 5000N and consists 8 leaves 46mm wide, two of the leaves being of full length. The spring is to be made 1000mmbetween the eyes and is held at the center by a 60mm wide band. Assume that thespring is initially stressed so as to induce an equal stress of 500N/mm2 when fullyloaded. Design the spring

(a) Thickness of leaves

(b) Eye diameter

(c) Length of leaves

(d) Maximum deflection and camber.Assume E = 2.1×105 N/mm2. [4×4=16]

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1. (a) Write short notes on free cutting steel and stainless steel.

(b) State the alloying elements added to steel and the effects they produce in steel.[8+8]

2. (a) Write Soderberg’s equation and state its application to different type of load-ings.

(b) Determine the diameter of a circular rod made of ductile material with afatigue strength. σe=265Mpa and a tensile yield strength of 350 Mpa. Themember is subjected to a varying axial load from Wmin=-300 kN to Wmax=700kN and has a stress concentration factor=1.8. Use factor of safty as 2.0. [6+10]

3. (a) What are the assumptions made in the welded joints.

(b) A 125 ×95×10 mm angle is joined to a frame by two parallel fillet welds alongthe edges of 150mm leg. The angle is subjected to a tensile load of 180 kN.Find the length of the weld if the permissible static load per mm weld lengthis 430 N. [4+12]


i. Major diameter

ii. Minor diameter

iii. Pitch

iv. Lead.


5. (a) A 10KW power is transmitted at 800 rpm, from a motor shaft ,through a key,to a machine shaft by a means of a pulley and a belt. Design the key. Takethe allowable shear stress and crushing stress are 45MPa and 100Mpa.

(b) Design a cotter joint to support a load of 50kN which is subjected to a slowreversal of a direction. Assume a suitable material and factor of safety andalso assume suitable allowable stresses. [8+8]

6. A hollow shaft carries a 90cm diameter CI pulley which is driven by another pulleymounted on a shaft placed below it through belt drive. The belt ends are paralleland vertical. The ratio of tensions in the belt is and H.P. transmitted is 50 at400rpm. The pulley mounted on the hollow shaft weighs 800N and overhangs thenearest bearing by 25cm. Calculate the diameter of the hollow shaft when the ratio

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of inside diameter to outside diameter is 0.5, when permissible shear stress for theshaft material is limited to 200N/mm2. [16]

7. Two shafts are connected by a flanged coupling. The flanges are fitted with 6 boltson 125mm bolt circle. The shafts transmit a torque of 800N-m at 350 rpm. Forthe safe stresses mentioned below. Calculate

(a) thickness of flanges

(b) diameter of bolts

(c) Key dimensions

(d) hub length

(e) power transmitted.

Safe shear stress for shaft material =63MPaSafe stress for bolt material =56MPaSafe stress for cast iron coupling =10MPaSafe stress for key material =46MPa. [16]

8. (a) Briefly explain the design of helical spring for fatigue loading.

(b) A helical coil spring is to be subjected, in service to loads ranging from 250to 325 N. The axial compression of the spring over the above load range isapproximately 5mm. Assuming a spring index of approximately 5, determinethe

i. size of wire

ii. outside diameter of the spring , and

iii. the number of active coils. [6+10]

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1. A load on a bolt consists of an axial pull of 10 k N together with a transver shearforce of 5 kN. Find the diameter of bolt required according to

(a) Maximum principal stress theory

(b) Maximum shear stress theory

(c) Max-principal strain theory

(d) Maximum strain energy theory.

Take permissible tensile stress at elastic limit=100 Mpa and Poisson’s ratio=0.3.[16]

2. (a) What is meant by endurance strength of a material. How do the size andsurface condition of a component and type of load affect such strength.

(b) Determine the stress for bolts in a cylinder cover where the load is fluctuatingdue to gas pressure. The maximum load on the bolt is 50 kN and minimum is30 kN. The load is unpredictable and factor of safty is 3. The surface of thebolt is not rolled and the surface finish factor is 0.9. [8+8]

3. (a) Classify the rivet heads according to Indian Standard Specification.

(b) A double riveted lap joint is made between 15mm thick plates. The rivetdiameter and pitch are 25mm and 75mm respectively. If the ultimate stressesare 400 MPa in tension and 320 MPa in shear and 640 MPa in crushing, findthe minimum force per inch, which will rupture the joint. If the above jointis subjected to a load such that the factor of safety is 4, find out the actualstresses developed in the plates and the rivets. [6+10]


i. Major diameter

ii. Minor diameter

iii. Pitch

iv. Lead.


5. (a) A line shaft 50mm in dia is to be driven by a belt, running over a 0.9 mdia pulley. The pulley is fitted on the shaft, by means of square key 15 mm×15mm×75mm. Determine the shear and crushing stresses induced in thekey.

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(b) Design a gib and cotter joint to connect square rods with a side of the squareas 25mm. Consider σt =60MPa σc = 90MPa and τ = 40MPa. The joint hasto carry a load of 35kN.(t=8mm,B=55(30+25)mm and length of the tail ofthe rod is 12mm.) [8+8]

6. (a) What is the comparison between solid shafts, hollow shafts and spindles.

(b) Compute the diameter of a solid shaft which has to transmit 16kW power at300rpm. Ultimate shear stress per shaft material is 350N/mm2 and factor ofsafety for design is 6. If a hollow shaft replaces the solid shaft, find the insideand outside diameters if the ratio is 0.5. [6+10]

7. Design a rigid sleeve coupling to connect two shafts, transmitting 18.75kW at1000rev/min. The allowable shear stress in the material of the shaft is 55 N/mm2.The material of the shaft and key is same and the coupling is required to transmit20% overload. The material of the sleeve is cast iron, the allowable shear stress forwhich is 16 N/mm2. Make a neat sketch of the designed sleeve coupling showingside view and sectional elevation. [16]

8. (a) Generally how the springs are classified? Indicate the different types of springsby sketches and give minimum two practical applications of each.

(b) Calculate the dimensions of a helical spring for a spring-loaded safety valvefrom the following data:valve diameter 65mmMaximum pressure when the valve blows off freely 0.73N/mm2

Valve lift when pressure rises from 0.7 to 0.73N/mm2 3.2mmMaximum permissible stress 500N/mm2

Spring index 5, Modulus of rigidity is 8×1010N/m2. Give a neat sketch of thefree spring showing the leading dimensions. [6+10]

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III B.Tech I Semester Supplementary Examinations, May 2010DIGITAL IC APPLICATIONS

( Common to Electronics & Communication Engineering and Electronics &Instrumentation Engineering)

Time: 3 hours Max Marks: 80Answer any FIVE Questions

All Questions carry equal marks? ? ? ? ?

1. (a) Design CMOS 4-input AND-OR-INVERT gate. Draw the logic diagram andfunction table.

(b) Draw the resistive model of a CMOS inverter and explain its behavior forLOW and HIGH outputs. [8+8]

2. (a) What is the necessity of separate interfacing circuit to connect CMOS gate toTTL gate? Draw the interface circuit and explain the operation.

(b) Design a TTL three-state NAND gate and explain the operation with the helpof function table. [8+8]

3. (a) Write a VHDL Entity and Architecture for the following function.

F (x) = (a + b) (c ⊕ d)

Also draw the relevant logic diagram.

(b) Write a VHDL Entity and Architecture for a 3-bit ripple counter using Flip-Flops? [8+8]

4. (a) Write a process based VHDL program for the prime-number detector of 4-bitinput and explain the flow using logic circuit.

(b) Explain data-flow design elements of VHDL. [10+6]

5. (a) Show the logic diagram of 74X283 binary adder. Explain the principle ofgenerating sum and carry at every stage using the logic diagram.

(b) Design a 24-bit group ripple adder using 74x283 ICs? [8+8]

6. A simple floating-point encoder converts 16-bit fixed-point data using four highorder bits beginning with MSB. Design the logic circuit and write VHDL data-flowprogram. [16]

7. (a) Differentiate between ripple counter and synchronous counter? Design a 4-bitcounter in both modes and estimate the propagation delay.

(b) Design a modulo-88 counter using 74X163 Ics. [8+8]

8. (a) Design an 8x4 diode ROM using 74X138 for the following data starting fromthe first location.

1, 4, 9, B, A, 0, F, C

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(b) Draw the internal structure of synchronous SRAM and explain its operation?[8+8]

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1. (a) Explain how to estimate sinking current for low output and sourcing currentfor high output of CMOS gate.

(b) Analyze the fall time of CMOS inverter output with RL = 100Ω, VL = 2.5V and CL =10PF . Assume VL as stable state voltage. [8+8]

2. (a) Design a TTL three-state NAND gate and explain the operation with the helpof function table.

(b) Explain the following terms with reference to TTL gate.

i. Voltage levels for logic ‘1’ & logic ‘0’

ii. DC Noise margin

iii. Low-state unit load

iv. High-state fan-out [8+8]

3. (a) Discuss the steps in VHDL design flow.

(b) Write a VHDL Entity and Architecture for the following function.F(x) = (a+b)(c+d)(e+f)Also draw the relevant logic diagram. [8+8]

4. (a) Design a logic circuit to detect prime number of a 4-bit input? Write theVHDL program for the above design?

(b) Design the logic circuit and write a data-flow style VHDL program for thefollowing function? [8+8]

F (P ) = ΣA,B,C,D (1, 5, 6, 7, 9, 13) + d (4, 15)

5. (a) Draw the digits created by 74x49 seven-segment decoder for non-decimal in-puts 1010 through 1111.

(b) Realize the following expression using 74×151 IC [8+8]

f(X) = ABC + ABC + ABC


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7. (a) Differentiate between ripple counter and synchronous counter? Design a 4-bitcounter in both modes and estimate the propagation delay.

(b) Design a modulo-88 counter using 74X163 Ics. [8+8]

8. (a) Explain the internal structure of 64K×1 DRAM. With the help of timingwaveforms discuss DRAM access.

(b) Design an 8×4 diode ROM using 74×138 for the following data starting fromthe first location. [8+8]

F, 2, 9, C, E, 1, F, A

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1. (a) Design a 4-input CMOS OR-AND-INVERT gate. Explain the circuit with thehelp of logic diagram and function table?

(b) Explain the following terms with reference to CMOS logic.

i. Logic ‘0’ and Logic ‘1’

ii. Noise margin

iii. Power supply rails

iv. Propagation delay [10+6]

2. (a) Draw the circuit diagram of basic TTL NAND gate and explain the threeparts with the help of functional operation.

(b) List out TTL families and compare them with reference to propagation delay,power consumption, speed-power product and low level input current. [8+8]

3. (a) Write a VHDL Entity and Architecture for the following function?

F(x) = a ⊕ b ⊕ c

Also draw the relevant logic diagram.

(b) Explain the use of Packages Give the syntax and structure of a package inVHDL [8+8]

4. Design a logic circuit to detect prime number of a 5-bit input. Write the structuralVHDL program for the same. [16]

5. (a) Design a full subtractor with logic gates and write VHDL data flow programfor the implementation of the above subtractor.

(b) Using the above subtractor design a 8-bit ripple subtractor and write thecorresponding VHDL program in structural style of modeling. [8+8]

6. (a) Design a barrel shifter for 8-bit using three control inputs? Write a VHDLprogram for the same in data flow style.

(b) Write a behavioral VHDL program to compare 16-bit signed and unsignedintegers [8+8]

7. (a) Design a switch debouncer circuit using 74×109 IC. Explain the operationusing timing diagram.

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(b) Discuss the logic circuit of 74×377 register. Write a VHDL program for thesame in structural style. [8+8]

8. (a) With the help of timing waveforms, explain read and write operations ofSRAM.

(b) Explain the internal structure of 64K×1 DRAM. With the help of timingwaveforms discuss DRAM access. [8+8]

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1. (a) Design a CMOS transistor circuit that has the functional behavior as

f(x) = (a + c). (b + c)

Also draw the relevant circuit diagram

(b) Design CMOS 4-input OR-AND-INVERT gate. Explain the circuit with thehelp of logic diagram and function table? [10+6]

2. (a) Design a transistor circuit of 2-input ECL NOR gate. Explain the operationwith the help of function table.

(b) Compare CMOS, TTL and ECL with reference to logic levels, DC Noise mar-gin, propagation delay and fan-out. [8+8]

3. (a) What is importance of Entity and Architecture in VHDL? Explain with suit-able examples.

(b) What are the different data objects supported by VHDL? Explain scalar typeswith suitable examples. [8+8]

4. (a) Explain data-flow design elements of VHDL.

(b) Design the logic circuit and write a data-flow style VHDL program for thefollowing function. [8+8]

F (X) = ΣA,B,C,D (1, 4, 5, 7, 12, 14, 15) + d (3, 11)

5. Explain the principle of carry look ahead Adder. Using this principle design a 6-bitcarry look ahead adder. Provide the logic diagram. Write the data flow VHDLprogram for the same. [16]


7. (a) Design an Excess-3 decimal counter using 74×163 and explain the operationwith help of timing waveforms.

(b) It is necessary to generate 6 control lines in regular intervals sequentially.Design the necessary circuit using 74×163 and 74×138. [8+8]

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8. (a) Discuss how PROM, EPROM and EEPROM technologies differ from eachother.

(b) With the help of timing waveforms, explain read and write operations ofSRAM. [8+8]

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Code No: V3128/R07

III B. Tech I Semester Supplementary Examinations, MAY 2010

MICROPROCESSORS AND INTERFACING

(Common to CSE, IT, ECC, & ICE)

Time: 3 Hours Max Marks: 80

Answer Any FIVE Questions

All Questions Carry Equal Marks

*****

1. a) What is memory segmentation? Explain different segments available in

8086 microprocessor.

b) Explain the flag register of 8086 microprocessor. [8+8]

2. Write an assembly language program in 8086 to arrange a given series of

hexadecimal numbers in descending order. [16]

3. a) List and explain the pins of 8086 which have special function for

minimum mode and maximum mode.

b) Explain the function of bus controller in maximum mode operation of

8086 microprocessor. [8+8]

4. Explain the architecture and various modes of operation of 8255. [16]

5. a) Differentiate between Initialization Command Words and Operation

Command Words of 8259.

b) Discuss about the interrupt priority schemes used in 8259. [10+6]

6. a) Discuss the types of serial communication.

b) With a neat circuit diagram, explain the interfacing of 8251 with 8086.

[6+10]

7. a) Explain the architecture of the Pentium processor.

b) Differentiate RISC and CISC processors. [8+8]

8. a) Draw the architectural diagram of 8051 microcontroller and explain in

detail about each block.

b) Explain the basic differences between a microprocessor and a

microcontroller [12+4]

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Code No: V3128/R07







*****

1. With a neat block diagram, explain the architecture of 8086 microprocessor.

[16]

2. a) Write an ALP to find out the number of even and odd numbers from a

given series of 16-bit hexadecimal numbers.

b) Write an ALP to find out whether a given byte is in the string or not.

[8+8]

3. Interface two 4k*8 EPROMs and two 4k*8 RAM chips with 8086

microprocessor. Select suitable maps. [16]

4. Interface DAC AD7532 with an 8086 CPU resuming at 8MHz and write an

assembly language program to generate a triangular waveform of period

2ms with Vmax 5V. [16]

5. a) Discuss in detail about the interrupt structure of 8086.

b) Describe about the interrupt vector table of Intel processors. [8+8]

6. a) Discuss the serial data transmission standards and their specifications.

b) Draw and explain the block diagram of 8251. [6+10]

7. a) List and explain the new Pentium instructions.

b) Explain the memory system of the Pentium processor. [8+8]

8. a) Draw the block diagram of 8051 microcontroller and explain its salient

features.

b) Explain the interrupt structure of the 8051 microcontroller. [10+6]

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Code No: V3128/R07







*****

1. a) Explain physical address calculation in 8086 microprocessor.

b) Explain different assembler directives of 8086 microprocessor. [8+8]

2. a) Write an assembly language program to find out the number of positive

numbers and negative numbers from a given series of signed numbers.

b) Write an ALP to decide whether the parity of a given multibyte numbers

is even or odd. If parity is even set DL to 00; else set DL to 01. [8+8]

3. Interface two chips of 32k*8 ROM and four chips of 32k*8 RAM with 8086

according to the following map.

ROM 1 and 2: F0000 H – FFFFF H,

RAM 1 and 2: D0000H - 0FFFF H,

RAM 3 and 4: E0000H – EFFFF H.

Show the implementation of this memory system. [16]

4. Design a stepper motor controller and write an ALP to rotate shaft of a 4-

phase, 200 teeth stepper motor.

a) in clockwise 5 rotations

b) in anticlockwise 5 rotations. [8+8]

5. a) What is the difference between maskable and non-maskable interrupts?

Give some examples?

b) Describe some important features of 8259 interrupt controller. [8+8]

6. Design a hardware interfacing circuit for interfacing 8251 with 8086. Set the

8251A in asynchronous mode as a transmitter and receiver with even parity

enabled, 2 stop bits, 8-bit character length, frequency 160 KHz and baud rate

10K. Write an ALP to receive 100 bytes of data string starting at location

3000:4000H. [16]

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Code No: V3128/R07

7. a) What do you mean by paging? What are its advantages and

disadvantages?

b) Explain the characteristics of RISC processors. [8+8]

8. With a neat diagram, explain the architecture of the 8051 microcontroller.

[16]

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Code No: V3128/R07







*****

1. Draw and explain the architecture of the 8086 microprocessor. [16]

2. Write an ALP to find out the product of two 3*3 size matrices. The matrices

are stored in the form of lists (row wise). Store the result in the third list.

[16]

3. a) What is DMA? Explain the need for DMA.

b) Explain the interfacing of 8257 with 8086 microprocessor. [8+8]

4. Interface a 12-bit DAC with 8255 and write a program to generate a

triangular waveform of period 10ms.The CPU runs at 5MHz clock

frequency. [16]

5. a) Describe some important features of 8259 interrupt controller.

b) Discuss about the following control word formats of 8259:

i. Initialization Command Words (ICWs).

ii. Operational Command Words (OCWs) [6+10]

6. Draw and discuss the asynchronous mode transmitter and receiver data

formats of 8251. [16]

7. a) What is meant by paging? Explain its advantages and disadvantages.

b) Explain the procedure of converting linear address into physical address.

[8+8]

8. a) Differentiate microprocessors and microcontrollers.

b) Explain different addressing modes of 8051 microcontroller with suitable

examples. [6+10]

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III B.Tech I Semester Supplementary Examinations, May 2010CHEMICAL REACTION ENGINEERING-I

(Chemical Engineering)Time: 3 hours Max Marks: 80


? ? ? ? ?

1. (a) Differentiate between single and multiple reactions.

(b) On doubling the concentration of reactant, the rate of reaction triples. Findthe reaction order.

(c) For the stoichiometry A + B → (products) find the reaction orders withrespect to A and B.

CA 2 2 3CB 125 64 64−rA 50 32 48

[4+2+10]

2. For a zero order reaction A→ B, 80% conversion is obtained in 1 hour if the initialconcentration is 1 kmol/m3 :

(a) Calculate the rate.

(b) Calculate time for obtaining 90% conversion.

(c) Calculate the conversion after 30 minutes of reaction. [4+6+6]

3. The gas reaction 2A→R + 2S is approximately second order with respect to A.When pure A is introduced at 1 atm into a constant-volume batch reactor, thepressure rises 40% in 3 min. For a constant- pressure batch reactor find

(a) The time required for the same conversion

(b) The fractional increase in volume at that time. [8+8]

4. For the liquid reaction A→ R the rate of reaction is given in the table. What sizeof plug flow reactor would be needed for 80% conversion of a feed stream of 1000mol A/hr at CA0 = 1.5 mol/liter? [16]CA,mol/liter −rA,mol/liter.min

0.1 0.10.2 0.30.3 0.50.4 0.60.5 0.50.6 0.250.7 0.100.8 0.061.0 0.051.3 0.0452.0 0.042

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5. At present 90% of reactant A is converted into product by a 2nd order reaction ina single mixed flow reactor. We plan to place a second reactor similar to the onebeing used in series with it.

(a) For the same treatment rate as that used at present, how will this additionaffect the conversion of reactant?

(b) For the same 90% conversion, by how much can the treatment rate be in-creased? [8+8]

6. Consider the aqueous reactions as shown in the figure 6:

Figure 6dCR

dt= 1.0C1.5

A C0.3B , mol/liter.min :: dCS

dt= 1.0C0.5

A C1.8B , mol/liter.min

For 90% conversion of A find the concentration of R in the product stream if theflow in the reactor is Plug flow of A and Mixed flow of B. Equal volumetric flowrates of A and B streams are fed to the reactor, and each stream has a concentrationof 20 mol/liter of reactant. [16]

7. Starting with separate feeds of reactant A and B of given concentration, for thecompetitive consecutive reactions with stoichiometry and rate as shown:

A + B → RDesired

A + B → SUnwanted

Sketch the contacting patterns for both continuous and non continuous operations.

(a) r1 = k1 CAC2

B r2 = k2 CRCB [8]

(b) r1 = k1 CACB r2 = k2 CRC2

B [8]

8. Reaction between A and B is irreversible and follows 2nd order kinetics. Thereaction is carried out in an adiabatic CSTR. A + 2B → Products. Reactionrate constant, k = 8 × 1012e−E/RT m3/k.mol.s, activation energy E = 76 kJ/mole.Initial concentration of A, CAO = 0.2kmol/m3, initial concentration of B, CBO =0.4kmol/m3. The feed rate of the reactor is 50cm3/s. Volume of CSTR is 8000 cm3,inlet feed temperature is 300C. The heat capacity of the inlet and outlet stream is4.0 j/g.0 C. Calculate

(a) Fractional conversion

(b) Temperature of the outlet stream. [16]

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1. (a) Differentiate between single and multiple reactions.

(b) On doubling the concentration of reactant, the rate of reaction triples. Findthe reaction order.

(c) For the stoichiometry A + B → (products) find the reaction orders withrespect to A and B.

CA 2 2 3CB 125 64 64−rA 50 32 48

[4+2+10]

2. (a) A 10 minute experimental run shows that 75% of liquid reactant is convertedto product by a 1/2 order rate. What would be the fraction converted in ahalf-hour run?

(b) In a homogeneous isothermal liquid polymerization, 20% of the monomer dis-appears in 34 minutes for initial monomer concentration of 0.04 and also for 0.8mol/liter. What rate equation represents the disappearance of the monomer?

[8+8]

3. (a) The first order reversible liquid reaction A →R, CA0 = 0.5 mol/liter, CR0 = 0takes place in a batch reactor. After 8 minutes, conversion of A is 33.3% whileequilibrium conversion is 66.7%. Find the rate equation for this reaction.

(b) Discuss about reactions of shifting order. [10+6]

4. (a) We plan to replace our present mixed flow reactor with one having doublethe volume. For the same aqueous feed (10 mol A/ liter) and the same feedrate find the new conversion. The reaction kinetics are represented by A →

R,−rA = kC1.5A , and present conversion is 70%.

(b) What will be the conversion if the original reactor is replaced by a plug flowreactor of equal size - all else remaining unchanged? [8+8]

5. It is desired to produce 200 million pounds per year of ethylene glycol. The reactoris to be operated isothermally. A one lbmole/ft3 solution of ethylene oxide in wateris feed to the reactor together with an equal volumetric solution of water contains0.9 wt% of H2SO4. If 80% conversion is to be achieved, determine the necessaryreactor volume? How many 800 - gal reactors would be required if they are arrangedin series? [16]

6. The parallel decomposition of A, CAO = 2 as given in the figure6,

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Figure 6

Determine the arrangement of reactors which would produce most S in a flow systemwhere recycle and reconcentration of unreacted feed is not possible. Find CS,total

for this arrangement of reactors. [16]

7. Starting with separate feeds of reactant A and B of given concentration, for thecompetitive consecutive reactions with stoichiometry and rate as shown:

A + B → RDesired

A + B → SUnwanted

Sketch the contacting patterns for both continuous and non continuous operations.

(a) r1 = k1 CAC2

B r2 = k2 CRCB [8]

(b) r1 = k1 CACB r2 = k2 CRC2

B [8]

8. Reaction between A and B is irreversible and follows 2nd order kinetics. The re-action is carried out in an adiabatic CSTR. A + 2B → Products. Reaction rateconstant,k = 6.8× 1011e−E/RT m3/k.mol.s, activation energy E = 76 KJ/mole. Ini-tial concentration of A, CAO = 0.2kmol/m3, initial concentration of B, CBO =0.4kmol/m3. The feed rate of the reactor is 25cm3/s. Volume of CSTR is 4000cm3, inlet feed temperature is 300 C. The heat capacity of the inlet and outletstream is 4.0 J/g.0C. Calculate

(a) Fractional Conversion

(b) Temperature of the outlet stream. [16]

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1. (a) The pyrolysis of ethane proceeds with an activation energy of about 75,000cal. How much faster is the decomposition at 6500C than at 5000C?

(b) Compare collision and transition state theories. Show that Arrhenius? law isa good approximation to the temperature dependency of both these theories.

[8+8]

2. (a) A constant volume batch reactor was operated at 100 C. The following datawere found at different intervals of time for a gas.

Time in minutes 0 4 8 12 16Partial pressure in mm Hg 760 475 320 240 150

Using the above mentioned data find out reaction rate equation.

(b) Write a brief note on integral method of analysis of autocatalytic reactions.[10+6]

3. The following data is on the reaction of sulphuric acid with diethylsulphate inaqueous solution at 22.90C.t,min C2H5SO4H mol/ltr t,min C2H5SO4H mol/ltr

0 0 180 4.1141 1.18 194 4.3148 1.38 212 4.4555 1.63 267 4.8675 2.24 318 5.1596 2.75 368 5.32127 3.31 379 5.35146 3.76 410 5.42162 3.81 ∞ (5.80)

H2SO4 + (C2H5)2SO4 → 2C2H5SO4H

Initial concentrations of H2SO4 and (C2H5)2SO4 are each 5.5 mol/liter. Find arate equation for this reaction. [16]

4. At 6500C phosphine vapor decomposes as follows:4PH3 → P4(g)+6H2,−rphos = (10hr−1)Cphos What size of plug flow reacor operat-ing at 6490C and 11.4 atm is needed for 75% conversion of 10 mol/hr of phosphinein a 2/3 phosphine and 1/3 inert feed? [16]

5. At present 90% of reactant A is converted into product by a 2nd order reaction ina single mixed flow reactor. We plan to place a second reactor similar to the onebeing used in series with it.

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(a) For the same treatment rate as that used at present, how will this additionaffect the conversion of reactant?

(b) For the same 90% conversion, by how much can the treatment rate be in-creased? [8+8]

6. Consider the aqueous reactions as shown in the figure 6:

Figure 6dCR

dt= 1.0C1.5

A C0.3B , mol/liter.min :: dCS

dt= 1.0C0.5

A C1.8B , mol/liter.min

For 90% conversion of A find the concentration of R in the product stream if theflow in the reactor is Plug flow of A and Mixed flow of B. Equal volumetric flowrates of A and B streams are fed to the reactor, and each stream has a concentrationof 20 mol/liter of reactant. [16]

7. The liquid phase reaction of aniline with ethanol produces wanted mono ethylanilineand unwanted diethylaniline.

C6H5NH2+C2H5OHk1H2SO4

−→ C6H5NHC2H5+H2O

C6H5NHC2H5+C2H5OHk2H2SO4

−→ C6H5N(C2H5)2

+H2O

k1 = 0.25k2

(a) An equimolar feed is introduced in to a batch reactor, and reaction is allowedto proceed to completion. Find the concentration of reactants and productsat the end of the reaction? [8]

(b) Find the ratio of mono to diethylaniline produced in a MFR for an alcohol toaniline feed ratio of 2 to 1 for 70% conversion of alcohol. [8]

8. Reactant A undergoes an essentially irreversible 1st order reaction A→ R. Both Aand R are liquid at room temperature, both have extremely high boiling points.Determine reactor volume necessary to produce one million kg of R in 7000 hr ofoperation if reactor operates isothermally at 163O C. Times necessary to fill, drainand clean the reactor are equal to 10, 12 and 14 minutes respectively. [16]

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? ? ? ? ?

1. (a) The decomposition of nitrous oxide (N2O) is found to be as follows:

N2O → N2 + 1/2O2, −rN2O = k1[N2O]2

1+k2[N2O]

What is the order of this reaction with respect to N2O, and overall?

(b) How can the kinetics of nonelementary reactions be explained? Briefly explainwith suitable example.

(c) What are the different types of intermediates formed in nonelementary reac-tions? Define each type. [4+4+8]

2. (a) Aqueous A at a concentration CA0 = 1mol/ltr is introduced into a batchreactor where it reacts away to form a product R according to stoichiometryA→ R. The concentration of A in the reactor is monitored at various times,as shown below:t,min 0 100 200 300 400CA, mol/m3 1000 500 333 250 200

For CA0 = 500 mol/m3 find the conversion of reactant after 5 hours in thebatch reactor.

(b) Find the rate for the reaction of the above problem. [14+2]

3. (a) Find the first order rate constant for the disappearance of A in the gas reac-tion 2A→ R if, on holding the pressure constant, the volume of the reactionmixture, starting with 80% A, decreases by 20% in 3 minutes.

(b) Explain the method of isolation and method of initial rates for the analysis ofbatch reactor data. [10+6]

4. (a) For the liquid reaction A→ R the rate of reaction is given in the table. Whatsize of mixed flow reactor is needed for 75% conversion of a feed stream of1000 mol A/hr at CA0 = 1.2 mol/liter?

(b) Repeat part (a) with the modification that the feed rate is doubled thus 2000mol A/hr at CA0 = 1.2 mol/liter are to be treated.

(c) Repeat part (a) with the modification that CA0 = 2.4 mol/liter; however, 1000molA/liter are still to be treated down to CAf = 0.3 mol/liter. [6+5+5]

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CA,mol/liter −rA,mol/liter.min0.1 0.10.2 0.30.3 0.50.4 0.60.5 0.50.6 0.250.7 0.100.8 0.061.0 0.051.3 0.0452.0 0.042

5. In the presence of a specific enzyme E, which acts as a homogeneous catalyst aharmful organic A presenting industrial waste water degrades in to harmless chem-icals. At a given enzyme concentration CE tests in a laboratory mixed flow reactorgive the following results:CAO,mmol/m3 2 5 6 6 11 14 16 24CA,mmol/m3 0.5 3 1 2 6 10 8 4

τ ,min 30 1 50 8 4 20 20 4

We wish to treat 0.1 m3/min of this waste water having CAO = 10 mmol/m3 to 90%conversion with this enzyme at concentration CE. A long tubular reactor assumingplug flow is to be used with possible recycle of exit fluid. What design do yourecommend? Give the size of the reactor, tell if it should be used with recycle, andif so determine recycle flow rate in m3/min. Sketch the recommended design?[16]

6. In a reactive environment, chemical A decomposes as follows figure6:

Figure 6

For a feed stream of CAO= 4 mol/liter, what size ratio of two mixed flow reactorswill maximize the production rate of R? Also give the composition of A and Rleaving these two reactors. [16]

7. Under the action of mixed enzymes reactant A is converted to products as follows:

Ak1+Enzyme−−−−−−−→, R

k1+Enzyme−−−−−−−→, S, k1 = pH2

− 8pH + 23, k2 = pH + 1, 2 < pH < 6, n1 = n2 = 1

What reactor set-up (Plug flow, Mixed flow, Staged mixed flow units) and whatuniform pH level would you use if R is the desired product. [16]

8. Using optimum temperature progression in a plug flow reactor for the reaction

between 00 C and 1000 C A ⇔ R

∆H298 = −75, 300 J/mol

∆G298 = −14, 130 J/mol

CPA = CPR =

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Const = 250cal/mol0KCalculate the space time and volume needed for 80% conversion of a feed ofFAO=1000mol/min, where CAO = 4mol/lit. [16]

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III B.Tech I Semester Supplementary Examinations, May 2010INDUSTRIAL INSTRUMENTATION

(Electronics & Instrumentation Engineering)Time: 3 hours Max Marks: 80


? ? ? ? ?

1. (a) Explain in detail about recent gauging techniques.

(b) Describe a method to find out the planners of a surface plate. [9+7]

2. Explain the different methods of measuring linear velocity using electromagnetictransducers. [16]

3. (a) Describe in detail about Ignition type Tachometers.

(b) Explain the basic principle of Stroboscopic Tachometer. [8+8]

4. (a) Draw the sketch and explain the principle and working of Beam type Loadcell.

(b) What are the applications of Load cells? Explain [8+8]

5. (a) Draw the sketch and explain the principle of Generalized II order system,representing a vibration pick-up transducer.

(b) Describe the principle and working of electromagnetic transducer. [8+8]

6. Suggest some methods that may be used to measure specific gravity. Explain howa Buoyancy method is used to measure density. [16]

7. What are the industrial needs which make viscosity determination desirable? Clas-sify the viscosity measuring instruments according to their principle of operation.

[16]

8. (a) What are the various electrical Hygrometers.

(b) Explain about Resistive Hygrometer. [8+8]

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? ? ? ? ?

1. (a) Give the general description of the measuring range of a length.

(b) Explain the nature of length.

(c) Explain the concepts of contacting and non-contacting type of length mea-surements. [5+5+6]

2. (a) What is translational velocity?

(b) How will you measure it?

(c) List out different methods to measure it.

(d) Describe the basic principle of any two methods. [4X4=16]

3. (a) A variable reluctance type tachometer has 60 rotor teeth. The counter records3600 counts per second. Determine the speed in rpm.

(b) An Inductive pick up operating from a 60 tooth wheel is used with a digitalfrequency meter to determine the speed of rotation of a shaft on which thewheel is mounted the gating period is set to 104µs and a reading of 0.024is obtained on 4 digital display. What shaft speed does this represent inr.p.s ? if the available gating periods are 102, 103, 104, 105, 106, 107and10µsrespectively, which would be the optimum setting of gating period for makingthis measurement.

(c) While measuring speed of a steam turbine with Stroboscope single line imageswere observed for Stroboscope setting of 3000, 4000 and 5230 rpm. Calculatethe speed of the turbine. [5+6+5]

4. A Barium titanate has the dimensions of 5mmx5mmx1.5mm.the young’s modulusof Barium titanate is 12x106 , its charge sensitivity is 150 PC/N and permitivity12.5 × 10−9 F/m. A capacitance of 10PF in parallel with 100MΩ resistance isconnected across the crystal. Calculate the rms value of voltage under open circuitand load conditions when a force of 0.0142 sin100t N is applied to the crystal.Calculate the rms value of deflection .The resistance of the crystal may be neglected.

[16]

5. (a) Explain the principle of measurements of frequency counter.

(b) Compare the frequency measurement methods using Frequency counters andOscilloscopes. [7+9]

6. (a) Explain with a neat diagram the radiation type of measuring density.

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(b) Explain briefly about specific gravity scales generally used in the petroleumindustries. [8+8]

7. (a) Explain briefly about viscosity relationships.

(b) What is kinematics viscosity.

(c) Explain the reasons for consistency measurement. [5+5+6]

8. (a) Explain specific humidity, DBT, WBT.

(b) Explain about Galvanometric Hygrometer. [8+8]

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1. (a) Explain in detail about recent gauging techniques.

(b) Describe a method to find out the planners of a surface plate. [9+7]

2. Describe briefly about the basic principle of Revolution counters and timers. [16]

3. Explain the principle of electrical tachometers. [16]

4. For the measurement of torque, four 120Ω resistance strain gauges having gaugefactor 2.0, are mounted on a shaft, 5 cm in diameter, at 45 to the axis of the shaftand are connected in a bridge configuration to get maximum sensitivity. For theshaft material, the Young’s modulus is 2.0x1011N/m2 and Poisson’s ratio is 0.3.Speed of the shaft is 1500 rpm. Excitation voltage to the bridge is 4.0 V. If theoutput voltage of the bridge is 3.5 m V, determine

(a) torque transmitted;

(b) power transmitted. [16]

5. Draw and explain the circuit of a digital frequency meter. What are the differentmethods used for high frequency determination. [16]



7. Explain the different methods of measuring consistency along with their usage. [16]

8. (a) Explain specific humidity, DBT, WBT.

(b) Explain about Galvanometric Hygrometer. [8+8]

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? ? ? ? ?

1. (a) What are mechanical comparators? Why is it used ? Give its classification.Explain each in detail .

(b) Describe the construction and working principle of mechanical optical com-parators. [9+7]

2. (a) Calculate the frequency ratio for which the error in acceleration is 1% if thedamping factor is 0.7.

(b) A Seismic Accelerometer sensing displacement has an undamped frequency of20Hz and a damping ratio 0.7. Calculate

i. Its damped frequency

ii. The amplitude ratio and phase angle between the motion of the seismicmass and the applied vibration, if the later is a sinusoidal displacementat a frequency of 30 Hz. [8+8]

3. Explain the principle of electrical tachometers. [16]

4. (a) With the help of a neat sketch explain the principle and working of columntype Load cell?

(b) Give the specifications of column type Load Cell? [8+8]

5. (a) Explain the principle of measurements of frequency counter.

(b) Compare the frequency measurement methods using Frequency counters andOscilloscopes. [7+9]



7. (a) List some devices for measuring viscosity in laboratory and industry. Explainany one of them.

(b) Explain velocity gradient for viscosity liquids by way of a velocity profile curve

[8+8]

8. (a) Explain about continuous recording psychrometer and explain Psychrometricchart.

(b) Explain abut calibration of humidity sensors. [9+7]

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III B.Tech I Semester Supplementary Examinations, May 2010AEROSPACE PROPULSION-I

(Aeronautical Engineering)Time: 3 hours Max Marks: 80


? ? ? ? ?

1. What is the basic principle of operation of a gas turbine engine? Explain variouscomponents with figures / sketches and its thermodynamics with a plot. [16]

2. A turbo-prop driven airplane is flying at 680 Km / h at an altitude where the ambi-ent conditions are 0.458 bar and -10oC. The compressor pressure ratio is 9.5:1 andthe turbine inlet temperature is 1250 K. The isentropic efficiencies of compressorand turbine are 0.85 and 0.90 respectively. Assuming that no thrust is generatedby the jet exhaust from the engine; calculate the specific power input available tothe propeller. [16]

3. Consider Ear type air intakes for a subsonic airplane as that for Gnat / Ajit fighterplane. Show the internal layout for the swallowed air to reach the engine. Explainits aerodynamics and thermodynamics in details when the airplane is derated inits flight prior to landing. [16]

4. Consider a conical spike type supersonic air inlet with fixed geometry for optimumperformance at one Mach number. Describe its aerodynamics and thermodynamicsat the design Mach number at a small angle of attack α = -2o ? [16]

5. What do you understand by ‘flame stabilization’? What are the various methodsused for flame stabilization in a combustion chamber? Explain the swirl vanemechanism with the help of a sketch. [16]

6. Describe the behaviour of the flow in a convergent-divergent nozzle when it isoperated at

(a) design pressure ratio,

(b) pressure ratio higher than the design value and

(c) pressure ratio lower than the design value. [16]

7. (a) Determine the pressure ratio of a single sided centrifugal compressor and thepower required to drive it, assuming that the velocity of air at inlet is axial,with the help of following data:Rotational speed = 270rev/sOverall diameter of impeller = 0.45mAir mass flow = 8kg/sInlet stagnation temperature = 290KIsentropic efficiency = 0.79Slip factor = 0.9

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(b) Derive the relationship for work done and pressure ratio of a centrifugal com-pressor. [16]

8. Distinguish between free vortex, constant reaction and forced vortex conditionswith the help of velocity diagrams for axial compressors. [16]

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? ? ? ? ?

1. Consider an actual gas turbine engine. How does each of its parts function toaccomplish the work of the engine? Illustrate with sketches and plots. Show thevariation of various parameters across the engine. [16]

2. A turbo-prop driven airplane is flying at 670 Km / h at an altitude where the ambi-ent conditions are 0.458 bar and -10oC. The compressor pressure ratio is 9.5 :1 andthe turbine inlet temperature is 1250 K. The isentropic efficiencies of compressorand turbine are 0.85 and 0.90 respectively. Assuming that no thrust is generatedby the jet exhaust from the engine; calculate the specific power input available tothe propeller. [16]

3. Consider a front air intake for a subsonic turbojet airplane as that for He-178 orF-86 Saber jet. Show the internal layout for the air to be swallowed by the engine.Explain its aerodynamics and thermodynamics in details when the airplane climbsat higher angles in its flight. [16]

4. Consider a conical spike type supersonic air inlet with fixed geometry for optimumperformance at one Mach number. Describe its aerodynamics and thermodynamicsat the design Mach number. What happens when the operating mach number isthe design Mach number at a small angle of yaw β = 2o ? [16]

5. (a) Explain the various factors affecting the design of a combustion chamber.

(b) Sketch an annular type of combustion chamber and explain its working. Dis-tinguish between annular and can type combustion chambers. [16]

6. Find the dimensions and the values of Cfg, Fg and CV of an axisymmetric exhaust-nozzle with a mass flow rate of 75kg/s with the following given data:Pt8 = 350 kPa Tt8 = 1600KA9/A8 = 1.8 R = 0.287 kJ/kg.K γ = 1.33Pt9/Pt8 = 0.98 CD = 0.98 P0 = 40 kPa [16]

7. A single-sided centrifugal compressor has to be designed with the following givendata:Power input factor = 1.04Slip factor = 0.9Rotational speed = 290rev/sOverall diameter of impeller = 0.5mEye tip diameter = 0.3mEye root diameter = 0.15m

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Inlet stagnation temperature = 295KInlet stagnation pressure = 1.1barAir mass flow = 9kg/sIsentropic efficiency = 0.78

(a) Determine the pressure ratio of the compressor and the power required todrive it assuming that the air at inlet is axial.

(b) Calculate the inlet angle of the impeller vane at the root and tip radii of theeye assuming that the axial inlet velocity is constant across the eye annulus.

[16]

8. The first stage of an axial compressor is designed on free vortex principle, withno inlet guide vanes. The rotational speed is 6000rev/min and the stagnationtemperature rise is 20K. The hub-tip ratio is 0.60, the work-done factor is 0.93and the isentropic efficiency of the stage is 0.89. Assuming an inlet velocity of140m/s and ambient conditions of 1.01bar and 288K, The first stage of an axialcompressor is designed on free vortex principle, with no inlet guide vanes. Therotational speed is 6000rev/min and the stagnation temperature rise is 20K. Thehub-tip ratio is 0.60, the work-done factor is 0.93 and the isentropic efficiency of thestage is 0.89. Assume an inlet velocity of 140m/s and ambient conditions of 1.01barand 288K. The rotor tip radius is 0.456m and corresponding rotor air angles β1 andβ2 are 63057’ and 56024’ if the Mach number relative to the tip is limited to 0.95.Calculate:

(a) The mass flow entering the stage.

(b) The stagnation pressure ratio and power required.The rotor air angles at the root section. [16]

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? ? ? ? ?

1. Consider an air standard Brayton cycle, where the air enters the compressor at0.11 Mpa,15o C .It leaves the compressor at 0.55 Mpa. TIT is 970o C. Determinepressure and temperature at each point in the cycle.Work out the efficiency of itscompressor,turbine and the overall engine. [16]

2. A turbo-prop driven airplane is flying at 600 Km / h at an altitude where the ambi-ent conditions are 0.455 bar and -10oC. The compressor pressure ratio is 9.5 :1 andthe turbine inlet temperature is 1250 K. The isentropic efficiencies of compressorand turbine are 0.85 and 0.90 respectively. Assuming that no thrust is generatedby the jet exhaust from the engine; calculate the specific power input available tothe propeller. [16]

3. Consider Ear type air intakes for a subsonic airplane as that for Gnat / Ajit fighterplane. Show the internal layout for the swallowed air to reach the engine. Explainits aerodynamics and thermodynamics in details when the airplane is derated inits flight prior to landing. [16]

4. Consider a conical spike type supersonic air inlet with fixed geometry for optimumperformance at one Mach number. Describe its aerodynamics and thermodynamicsat the design Mach number at a small angle of attack α = -2o ? [16]

5. What are the various types of burners used for fuel injection system in gas turbines?Which one will you prefer and why? [16]

6. A supersonic nozzle expands air from p0 = 25bar and T0 = 1050K to an exit pressureof 4.35bar. The exit area of the nozzle is 100cm2. Determine

(a) throat area,

(b) the temperature at exit,

(c) pressure and temperature at throat,

(d) exit velocity as fraction of the maximum attainable velocity and

(e) mass flow rate. [16]

7. A 0.4m diameter rotor of a centrifugal compressor for air is needed to producea pressure ratio of 3.8. Assuming a polytropic efficiency of 0.85, determine theangular speed, total temperature rise and adiabatic efficiency. Also determine theinput power for a mass flow rate of 2kg/s at 1atm and 288.2K. Assume a slip factorof 0.9. [16]

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8. An axial flow compressor has an overall pressure ratio of 4.0 and mass flow of 3kg/s.If the polytropic efficiency is 88% and the stagnation temperature rise per stagemust not exceed 25K, calculate the number of stages required and pressure ratioof the first and last stages. Assume equal temperature rise in all stages. If theabsolute velocity approaching the last rotor is 165m/s at an angle of 200 from theaxial direction, the work done factor is 0.83, the velocity diagram is symmetricaland the mean diameter of the last stage rotor is 18cm, calculate the rotationalspeed and the length of the last stage rotor blade at inlet to the stage. Ambientconditions are 1.01bar and 288K. [16]

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? ? ? ? ?

1. Consider an air standard Brayton cycle, where the air enters the compressor at0.1 Mpa,15o C .It leaves the compressor at 0.5 Mpa. TIT is 900o C. Determinepressure and temperature at each point in the cycle.Work out the efficiency of itscompressor,turbine and the overall engine. [16]

2. Explain with a lay out sketch the arrangement of a turbo-prop engine and itsthermodynamic cycle of operation. Describe the role of each component in anintegrated manner. [16]

3. Consider a front air intake for a subsonic turbojet airplane as that for He-178 orF-86 Saber jet. Show the internal layout for the air to be swallowed by the engine.Explain its aerodynamics and thermodynamics in details when the airplane is inits cruising flight. [16]

4. Consider a conical spike type supersonic air inlet with fixed geometry for optimumperformance at one Mach number. Describe its aerodynamics and thermodynamicsat the design Mach number. What happens when the operating mach number isthe design Mach number at a small angle of yaw β = 2o ? [16]

5. What do you understand by ‘flame stabilization’? What are the various methodsused for flame stabilization in a combustion chamber? Explain the swirl vanemechanism with the help of a sketch. [16]

6. Find the dimensions and the values of Cfg, Fg and CV of an axisymmetric exhaust-nozzle with a mass flow rate of 75kg/s with the following given data:Pt8 = 350 kPa Tt8 = 1600KA9/A8 = 1.8 R = 0.287 kJ/kg.K γ = 1.33Pt9/Pt8 = 0.98 CD = 0.98 P0 = 40 kPa [16]

7. An aircraft engine is fitted with a single-sided centrifugal compressor. The a/c flieswith a speed of 230m/s at an altitude where the pressure is 0.23bar and the tem-perature is 217K. The intake duct of the impeller eye contains fixed vanes whichgives the air pre-whirl of 25 degree at all radii. The inner and outer diameters ofthe eye are 18cm and 33cm respectively. The diameter of the impeller peripheryis 54cm and the rotational speed is 270rev/s. Estimate the stagnation pressure atthe compressor outlet when the mass flow is 3.6kg/s.Neglect losses in the inlet duct and fixed vanes and assume the isentropic effi-ciency of the compressor is 0.80. Take slip factor and input factor as 0.9 and 1.04respectively. [16]

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8. The first stage of an axial compressor is designed on free vortex principle, withno inlet guide vanes. The rotational speed is 6000rev/min and the stagnationtemperature rise is 20K. The hub-tip ratio is 0.60, the work-done factor is 0.93and the isentropic efficiency of the stage is 0.89. Assuming an inlet velocity of140m/s and ambient conditions of 1.01bar and 288K, The first stage of an axialcompressor is designed on free vortex principle, with no inlet guide vanes. Therotational speed is 6000rev/min and the stagnation temperature rise is 20K. Thehub-tip ratio is 0.60, the work-done factor is 0.93 and the isentropic efficiency of thestage is 0.89. Assume an inlet velocity of 140m/s and ambient conditions of 1.01barand 288K. The rotor tip radius is 0.456m and corresponding rotor air angles β1 andβ2 are 63057’ and 56024’ if the Mach number relative to the tip is limited to 0.95.Calculate:

(a) The mass flow entering the stage.

(b) The stagnation pressure ratio and power required.The rotor air angles at the root section. [16]

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Code No: V3124/R07


TRANSPORT PHENOMENA IN BIOPROCESS

(Biotechnology)




*****

1. (a) What do you understand about boundary conditions and write the

boundary conditions used for obtaining velocity distributions for various

situations [10 M]

(b) Explain cone – plate viscometer [6 M]

2. Laboratory scale fermenters are usually mixed using small stirrers with

electric motors rated between 100 and 500W, one such motor issued to drive

a 7cm turbine impleller in small reactor containing fluid with the properties

of water. The stirrer speed is 900rpm. Estimate the power requirements for

this process. How do you explain the difference between the amount of

electrical power consumed by the motor and the power dissipated by the

stirrer

3. (a) Write the effect of temperature on conductivity of solids, liquids and

gases.

(b) A plane wall 0.15cm thick, of a homogeneous material with k=0.40

W/m.K,has steady and uniform temperatures T1=20OC and

T2=70OC.Determine the heat transfer rate in the positive x-direction per

square meter of surface area. [8+8 M]

4. A solid metal occupying the space from y: 0 to y: initially at temperature

T0 , at time t=0 the surface at y=0 is suddenly raised to temperature T1 and

maintained at that temperature for t>0, write the partial differential equation

for this situation where temperature is function of time and y coordinate.

Also write the boundary condition for this situation. Do not attempt to solve

problem.

5. (a) Explain the rate of diffusion in bio-processing

(b)What is “Reynolds analogy” and what is its significance?

(c)Define Prandtl mixing length [8+4+4 M]

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Code No: V3124/R07

6. Explain boundary layer theory with neat sketch. How mass transfer

coefficient is related to the diffusion coefficient.

7. What are the various correlations for evaluating mass transfer coefficients

and interfacial for gas-liquid transfer?

8. (a) What are the factors that will be effecting oxygen transfer rate [8 M]

(b) Explain how KLa is measured by using Oxygen balance method [8 M]

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Code No: V3124/R07



(Biotechnology)




*****

1. (a) Explain briefly about turbulent flow with emphasis on time smoothed

velocity distributions in turbulent flow

(b) Describe the different factors effecting broth viscosity? [8+8 M]

2. A cylindrical stirred bioreactor of diameter and height 2m has a Rushton

turbine one third the rank diameter in size. The bioreactor contains

Newtonian culture broth with the same density as water and with viscosity

4cP. If the specific power consumption must not exceed 1.5kW m-3

determine the maximum allowable stirrer speed. What is the mixing time

under these conditions? The tank is now acrated. In the presence of gas

bubbles. The approximate relationship between ungassed power number

(Np)0 and gassed power number (Np)g is (Np)g = 0.5 (Np)o. What maximum

stirrer speed is now possible in the sparged reactor? Estimate the mixing

time.

3. (a) What is thermal diffusivity and write its analogy terms in momentum

transfer.

(b) Determine the steady state rate of heat transfer per unit area through a

4.0cm thick homogeneous slab with its two faces maintained at uniform

temperature of 380C and 21

0C.The thermal conductivity of the material is

0.19W/m.K. [8+8 M]

4. A solid slab occupying the space between y=-b and y=+b is initially at

temperature T0 , at time t=0 the surface at y=±b is suddenly raised to

temperature T1 and maintained there. Write the partial differential equation

for this situation where temperature is function of time and y coordinate.

Also write the boundary condition for this situation. Do not attempt to solve

problem.

5. We wish to obtain a differential equation for the situation where a volatile

liquid a evaporates into pure B in a tube of infinite length. The liquid level is

maintained at z=0 at all times. The temperature and pressure are assumed

constant, and the vapors of A and B form an ideal gas mixture. Hence the

molar density C is constant through the gas phase, and DAB may be

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Code No: V3124/R07

considered to be constant. It is further assumed that species B is insoluble in

liquid A, and that the molar average velocity in the gas phase does not

depend on the radial coordinate.

6. Explain briefly Reynolds analogy and Prandtl analogy for the estimation of

mass transfer coefficient.

7. Explain briefly the concept of Convective mass transfer?

8. Explain different mass transfer steps in transferring of Oxygen from Gas

bubble to aerobic culture?

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Code No: V3124/R07



(Biotechnology)




*****

1. (a) Compare and contrast the molecular and convective mechanisms for

momentum transport.

(b) Give a brief account on Non-Newtonian fluids with the help equations

relating shear stress and strain? [8+8 M]

2. Derive an equation of continuity for rectangular coordinate system and

simply for incompressible fluids.

3. (a)What is thermal conductivity? What are different mechanisms of Energy

transport?

(b)Estimate the thermal conductivity in W/mK of steam at 713 K and 130

atm.It is given that critical temperature and critical pressure are 647.4 K and

218.3atm (Generalized correlation chart for thermal conductivity should be

provided during examination) [8+8 M]

4. An iron sphere of 1in diameter has the following physical properties :

k=30btu/hr.ft.oF, cp=0.12btu/lbm.

oF and =436lbm/ft

3.Initially the sphere is

at a temperature of 70oF

(a)What is the thermal diffusivity of the sphere?

(b)If the sphere is suddenly plunged into a large body of fluid of

temperature 270oF, how much time is needed for the centre of the sphere to

attain a temperature of 128oF?

5. Explain about the Analogy between Mass, Heat and Momentum transport?

6. (a) Discuss the physical basis for the film model, the penetration model and

the boundary layer model for heat and mass transfer.

(b) Write the few situations where the mass transfer coefficients are required

instead of diffusion coefficients for the estimation of mass transfer flux.

[8+8 M]

7. Serratia marcesceens bacteria are used for production of threonine. The

maximum specific oxygen uptake rate of S. marcescens in batch culture is

5mmol O2 g-1

h-1

. The bacteria are grown in a stirred fermenter to a cell

density of 40 g1 -1

, kLa under these circumstances is 0.15 S-1

at the termenter

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Code No: V3124/R07

operating temperature and pressure, the solubility of oxygen in the culture

liquid is 8 x 10-3

kg m-3.

Is the rate of cell metabolism limited by mass

transfer, or dependent solely on metabolic kinetics?

8. A genetically engineered strain of years is cultured in a bio reactor at 30oC

for production of heterologous protein. The oxygen requirement is 80mmol

1-1

h-1

. The critical oxygen concentration is 0.004mM. the solubility of

oxygen in the fermentation broth is estimate to be 10% lower than in water

due to solute effects. (a) What is the minimum mass transfer coefficient

necessary to sustain this culture if the reactor is sparged with air at

approximately 1 atm pressure? (b)What mass transfer coefficient is required

if pure oxygen is used instead of air?

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Code No: V3124/R07



(Biotechnology)




*****

1. (a) Verify that “momentum per unit area per unit time” has the same

dimensions as force per unit area.

(b) A Fermentation broth with viscosity 10-2

Pa s and density 1000Kg m-3

is

agitated in a 2.7m3 baffled tank using a Ruston turbine with diameter 0.5m

and stirrer speed 1 S-1

, estimate the mixing time.

2. (a) To ensure turbulent conditions (Reynolds number must be at least 104)

and minimum mixing time during agitation in a stirred laboratory scale

fermenter with a turbine impeller 5cm in diameter is operated at 800rpm. If

the density of broth being stirred is close to that of water, what is the upper

limit for viscosity of the suspension if adequate mixing is to be maintained?

(b) Differentiate between substantial time derivative and total derivative

[10+6 M]

3. (a) Estimate the thermal conductivity in W/mK of steam at 65 atm and 575K

atm.It is given that critical temperature and critical pressure are 647.4 K and

218.3atm (Generalized correlation chart for thermal conductivity should be

provided during examination).

(b) Derive an expression for steady state heat conduction through composite

wall consisting of two layers. [8+8 M]

4. It is desire to bond together two sheets of solid material, each of thickness

0.77cm.this is done by using a thin layer of thermo setting material, which

fuses and forms a good bond at 160oC. The two plates are inserted in a press,

with both platens of the press maintained at a constant temperature of 220oc.

How long will the sheets to have been held in the press, if they are initially

at 20oC? The solid sheets have a thermal diffusivity of 4.2*10

-3cm

2/s.

5. Explain about boundary layer theory and Concentration distribution in

turbulent flow?

6. (a) How are the mass transfer coefficients affected by high mass transfer

rates across the interface [6 M]

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Code No: V3124/R07

(b) Give a brief description on Penetration theory and how mass transfer

coefficient is related to diffusion coefficient according to this theory. [10 M]

7. Explain different mass transfer steps in transferring of Oxygen from Gas

bubble to aerobic culture and also explain out all these resistance which are

more rate controlling steps?

8. The dynamic method is used to measure kLa in fermenter operated at 30oC .

Data for dissolved oxygen concentration as a function of time during the re

oxygenation step is as follows :

Time (s) CAL(%air saturation )

10 43.5

15 53.5

20 60.0

30 67.5

40 70.5

50 72.0

70 73.0

100 73.5

130 73.5

The equilibrium concentration of oxygen in the broth is 7.9 x 10-3

kg m-3.

Determine kLa.

bt31R0707

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