(DME 311) - AnucdeThese masses are revolving at radii 135 mm, 105mm, 150 mm and 180mm respectively...

(DME 311)

B.Tech. DEGREE EXAMINATION, DEC. - 2013

(EXAMINATION AT THE END OF THIRD YEAR THIRD SEMESTER)

Mechanical Engineering

Paper - I : OPERATIONS RESEARCH

Time : 03 Hours Maximum Marks : 75

Answer Question No. 1 is compulsory. [5 × 3 = 15]

Answer ONE question from each unit [4 × 15 = 60]

1) Write a brief note on.

a) Surplus and slack variables.

b) Degeneracy in LPP.

c) Scope of Operations Research.

d) North West corner method.

e) Characteristics of D.P

UNIT I

2) a) Explain Applications of LPP.

b) Solve the following LPP by Graphical method.

Maximize Z = 40x + 30y subject to the constraints.

50x + 36y 100000≤

25x + 36y 100000≤

, 0x y ≤

(OR)

3) Solve by simplex method:

Max. Z = 10x1 + 15x2 + 20x3

10x1 + 5x2 + 2x3 ≤ 2750

5x1 + 10x2 + 4x3 ≤ 2210

0.7x1 + x2 + 2x3 ≤ 445

x1, x2, x3 ≥ 0

UNIT-II

4) A branch of a Nation Bank has only one typist. Since the typing work varies in

length, the typing rate is randomly distributed as Poisson distribution with mean

rate of 8 letters per hour. The letters arrive at a rate of 5 per hour the 8 hour

during working day. Determine:

a) Equipment utilization.

b) Average system time.

c) Average idle time.

(OR)

5) A dealer stocks and sells four types of Bicycles namely Atlas, Bharath,

Champion, Duncan which he may procure from three different suppliers namely

Priyanshu, Qureshi and Raju. His anticipated sales for the bicycles for the

coming seasons are 410, 680, 310 and 550 nos respectively. He can obtain 900

bicycles from priyanshu 600 from Qureshi and 560 from Raju at suitable the

profit bicycle in rupees for each suppliers is tabulated below:

Supplier

Type

ATLAS BHARATH CHAMPION DUNCAN

PRIYANSHU 21.50 26 19.5 21

QURESHI 20.5 24 20 21

RAJU 18 19.5 19 19.5

Formulate the above information as transportation model and obtain initial

solution by North West corner rule.

UNIT-III

6) With neat sketches explain the following:

a) Rules for drawing network diagram.

b) Common errors in drawing networks.

OR

7) A project schedule has the following characteristics:

Activity Time

1-2 4

1-3 1

2-4 1

3-4 1

3-5 6

4-9 5

5-6 4

5-7 8

6-8 1

7-8 2

8-10 5

9-10 7

a) Construct network diagram.

b) Compute Earliest time and Latest time for each event.

c) Find the critical path.

UNIT-IV

8) a) Explain the maximin and minimax principle with examples.

b) Solve the game whose pay-off matrix is given by graphical method.

B1 B2 B3 B4

A1 4 -2 3 -1

A2 -1 2 0 1

A3 -2 1 -2 0

(OR)

9) a) Explain in brief the characteristics of dynamic programming model.

b) Use Dynamic programming to solve the following LPP.

Maximize : Z = 3x1 + 7x2 subjected to

x1 +4x2≤ 8

x2 ≤ 2

x1, x2≤ 0

��

(DME 312)


(Examination at the end of Third Year Third Semester)


Paper – II : DESIGN OF MACHINE ELEMENTS


Answer question no.1 is compulsory

Answer ONE question for each unit

1) Write brief note on :

a) Malleability and Ductility.

b) Importance of Factor of safety in design.

c) Good man diagram.

d) Efficiency of Screw jack..

e) Eccentrically loaded welded joints.

UNIT – I

2) a) What are the steps to be followed while designing a machine element?

b) Discuss briefly the important factors to be considered in the selection of materials.

(OR)

3) A load on bolt consists of an axial pull of 10 kN together with a transverse shear force of 5

kN. Find the diameter of bolt required according to

i) Maximum principal stress theory

ii) Maximum shear stress theory

iii) Max-principal strain theory

iv) Maximum strain energy theory.

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

UNIT – II

4) A hot rolled steel shaft is subjected to a torsional moment that varies from 330 N-m

clockwise to 110 N-m counter clock wise and an applied bending moment at a critical

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 shaft diameter. The material has an

ultimate strength of 550 M N/m2 and yield strength of 410 MN/m

2. Take the endurance

limit as half the ultimate strength, factor of safety of 2, size factor of 0.85 and surface finish

factor of 0.62.

(OR)

5) a) Derive the expression for the efficiency of the inclined plane, when the body is

moving up the plane.

b) The mean diameter of a square threaded screw jack is 50 mm. The pitch of the thread

is 10 mm. The coefficient of friction is 0.15. What force must be applied at the end of

a 0.7 long lever, which is perpendicular to the longitudinal axis of the screw to raise a

load of 20 kN and to lower it?

UNIT – III

6) a) What is the difference between caulking and fullering? Explain with the help of neat

sketches?

b) Show by neat sketches the various ways in which a riveted joint fail?

(OR)

7) A plate 75 mm wide and 12.5 mm thick is joined with another plate by a single transverse

weld and a double parallel filled weld as shown in figure. The maximum tensile and shear

stresses are 70 MPa and 56 MPa respectively. Find the length of each parallel fillet weld, if

the joint is subjected to both static and fatigue loading. Assume a length of 12.5 mm for

starting and stopping of weld run. Take stress concentration factor for transverse weld as

1.5 and for parallel fillet welds as 2.5?

UNIT – IV

8) The cylinder head of a steam engine is subjected to a steam pressure of 0.7 N/mm2. It is

held in position by means of 12 bolts. A soft copper gasket is used to make the joint leak

proof. The effective diameter of cylinder is 300 mm. Find the size of the bolt so that the

stress in the bolts is not to exceed 100 MPa.

(OR)

9) a) Write a short note on bolts of uniform strength.

b) Describe the design procedure of sleeve & cotter joint.

��

(DME 313)


(Examination at the end of Third Semester)


Paper - III : MACHINE DYNAMICS


Answer question No. 1 compulsory

Answer ONE question from each unit (4×15=60)

1) a) What is meant by piston effort?

b) What is meant by dynamic balancing?

c) What is mean by sensitiveness of governors?

d) What is mean by resisting torque?

e) Explain the term precession.

f) Explain the term primary disturbing force.

g) What is the function of a flywheel? How does it differ from that of a governor?

Unit - I

2) A single cylinder four stroke oil engine develops 15kW at a speed of 400 rpm and drives a

machine at 750rpm. The engine shaft carries a flywheel with a moment of inertia of 114

kg-m2. The machine shaft also carries a flywheel with the moment of inertia of 8 kg-m2. If the

fluctuation of energy is 80If the coefficient of fluctuation of speed is required to be lowered to

a total value of 1%, what is the moment of inertia of the additional rotating mass to be fitted to

the machine shaft?

OR

3) The crank of a three-cylinder single - acting engine are set equally at 120o the engine speed is

540 rpm. The turning-moment diagram for each cylinder is a triangle for the power stroke with

a maximum torque of 100 N-m at 600 after dead centre of the corresponding crank. On the

return stroke, the torque is sensibly zero.

Determine

i) the power developed

ii) the coefficient of fluctuation of speed if the flywheel has a mass of 7.5 kg with a radius of

gyration of 65 mm.

iii) the coefficient of fluctuation of energy

iv) the maximum angular acceleration of the flywheel.

Unit - II

4) A band and block brake having 12 blocks, each of which subtends an angle of 160 at the centre,

is applied to a rotating drum of diameter 600mm. the blocks are 75 mm thick. The drum and the

flywheel mounted on the same shaft have a mass of 1800kg and have a Combined radius of

gyration of 600mm. The two ends of the band are attached to pins on the opposite sides of the

brake fulcrum at distance of 40 mm and 150 mm from the fulcrum. If a force of 250 N is

applied at a distance of 900 mm from the fulcrum, find;

i) the maximum braking torque

ii) the angular retardation of the drum

iii) the time taken by the system to be stationary from the rated speed of 300rpm. Take

coefficient of friction between the blocks and the drum as 0.3.

OR

5) Four masses (m1, m

2, m

3, and m

4) 300kg, 450kg, 360kg and 390 kg are attached to a shaft.

These masses are revolving at radii 135 mm, 105mm, 150 mm and 180mm respectively in

planes measured from A at 135 mm, 210 mm and 360 mm respectively. The angle measured

anti-clockwise are m1 to m

2 450, m

2 to m

3 75o, m

3 to m

4 1350 and the distance between the

planes L and M in which the balance masses are to be placed is 250 mm. The distance between

planes A and L is 60 mm and M and D is 50 mm. If the balancing masses revolve at a radius of

36mm, find their magnitudes and angular positions.

Unit - III

6) A gear engine automobile is traveling along a curved track of 120m radius. Each of the four

wheels has a moment of inertia of 2.2kg-m2 and an effective diameter of 600mm. The rotating

parts of the engine have a moment of inertia of 1.25kgm2. The gear ratio of the engine to the

back wheel is 3:2. The engine axis is parallel to the gear axle and the crank shaft rotates in the

same sense as the road wheels. The mass of the vehicle is 2,050kg and the center of mass is 520

mm above the road level. The width of the track is 1.6m. What will be the limiting speed of the

vehicle if all the four wheels maintain contact with the road surface?

OR 7) An aero plane flying at 240km/hr turns towards left and completes a quarter circle of 60m

radius. The mass of the rotary engine and the propeller of the plane amounts to 450kg with a

radius of gyration of 320mm. The engine speed is 2000 rpm clockwise when viewed from the

rear. Determine the gyroscopic couple on the aircraft. Explain how do you find the effect of it

on the stability of the aero plane with the help of different diagrams. In what way is the effect

changed when.

i) The aero plane turns towards right.

ii) The engine rotates clockwise when viewed from the front nose end and the aero plane

turns

a) left

b) right.

Unit - IV

8) The following data relate to a Hartnell governor M = 1.5kg; a = 100 mm; b = 40 mm; r1 = 70

mm; r2 = 110 mm; N

1 = 260 rpm; and N

2 = 275 rpm. The axis of rotation is 80mm from the

fulcrum. Calculate the rate of the spring and the equilibrium speed when the radius of the balls

is 80 mm.

OR

9) The mass of each ball of a proell governor is 3 kg and the weight on the sleeve is 20kg each arm

is 220 mm long and the pivots of the upper and the lower arms are 20mm form the axis. For the

mid position of the sleeve the extension links of the lower arms are vertical, the height of the

governor 180 mm and the speed 150 rpm. Determine the lengths of the extension links and the

tension in the upper arms.

��

(DME 314)

B.Tech. DEGREE EXAMINATION, DEC - 2013

(Examination at the end of Third Year)

MECHANICAL ENGINEERING

Paper - IV : HYDRAULIC MACHINES

Time : Three hours Maximum : 75 marks

Answer Question No. 1 compulsory. (5x3=15)

Answer ONE question from each Unit. (4x15=60)

1) a) Give the classification of Fluid machines

b) What is meant by governing of turbine ?

c) What is cavitation ?

d) What are model laws ?

e) What are hydraulic systems ?

UNIT - I

2) a) Draw typical velocity triangles for fluid motion along a series of moving curved vanes

and explain the salient features.

b) A jet of water having a velocity of 30 m/s strikes a curved vane which is moving with

a velocity of 15 m/s. The jet makes an angle of 300 with the direction of motion of

vane at inlet and leaves at an angle of 1200 to the direction of motion of vane at outlet.

Calculate vane angles if the water enters and leaves the vane without shock and work

done per second per unit weight of water striking the vanes per second. (5+10)

(Or)

3) 5 cm diameter jet having a velocity of 20m/sec, strikes a flat plate, the normal of which is

inclined at 250 to the axis of the jet. Calculate the normal force exerted on the plate

a) When the plate is stationary

b) When the plate is moving with a velocity of 10m/sec in the direction of the jet.

c) When the plate is moving with a velocity of 7m/sec parallel to itself and in the direction

of the normal to its surface. (5+5+5)

UNIT - II

4) a) Show that Pelton Wheel is a low specific speed turbine.

b) What is specific speed ? State its significance in the study of hydraulic machines. (7+8)

(Or)

5) Define the terms unit head, suction specific speed, unit power, unit speed and unit discharge

with reference to a hydraulic turbine. Also derive expressions for these terms. (15)

UNIT - III

6) A double acting reciprocating pump has a stroke of 250mm and plunger diameter 125 mm.

The center of the pump is 4m above the lower sump water level and 30m below the delivery

water. The lengths of suction and delivery pipes are 6m and 35m respectively. Both pipes

are 60 mm in diameter. If the pump is to run at 30 rpm, find the pressure head on the

piston, at the beginning, middle and end of the suction stroke. If mechanical efficiency is

75% and f=0.04, determine the power required to drive the pump. (15)

(Or)

7) a) What do you mean by manometric efficiency, mechanical efficiency and overall

efficiency of a centrifugal pump.

b) A centrifugal pump is to discharge 0.118 m3/s at a speed of 1450 r.p.m. against a head

of 25m. The impeller diameter is 250 mm, its width at outlet is 50mm and manometric

efficiency is 75%. Determine the vane angles at the outer periphery of the impeller. (7+8)

UNIT - IV

8) a) If the friction factor 'f' in Darcy's formula hL = f (L V2/2gd) depends on velocity V,

diameter D, density , Viscosity µ and the surface roughness K, obtain a functional

relationship for 'f' by Buckingham's - theorem.

b) Obtain the expression for capillary rise through a small diameter tube D, immersed in

a liquid of specific weight , with a surface tension , using Rayleigh's method. (8+8)

(Or)

9) a) Describe with the help of a schematic diagram the construction, working and

performance of a hydraulic ram.

b) A hydraulic press has diameter of ram 200 mm and of a plunger 40 mm. It is provided

with a lever for applying force to the plunger. If the ratio of leverage is 10, determine

the weight lifted by the press, when the force applied to the level is 100 N. (7+8)

��

(DME 315 )


(Examination at the end of Third YearThird Semester)


Paper - V : IC ENGINES AND GAS TURBINES


Answer Question No.1 is compulsory (15)

Answer One question from each unit (4x15=60)

1) a) Why do designers go for multi-cylinder engines for heavy loads?

b) Draw value timing diagram for 4- stroke C.I. engine.

c) What is pre-ignition?

d) What is the effect of compression ratio on thermal efficiency?

e) Differentiate between positive displacement type and dynamic rotary

compressors.

f) What are the basic components of a Gas turbine plant?

g) Define thrust and propulsive efficiency of rocket engines.

Unit -I

2) a) Write the differences between 4-stroke and 2-stroke engines.

b) Briefly explain the following:

i) Time loss factor

ii) Heat loss factor

OR

3) a) Explain the working principle of simple carburettor with a neat sketch.

b) Explain the working principle of pneumatic governor with a neat sketch.

Unit -II

4) A single cylinder four stroke gas engine has a cylinder diameter of 20cm and stroke 40cm. The

observations made in a test of the engine are, torque=407 N-m, speed=250rpm, imep=6bar, oil

consumption=4kg/hr, calorific value of fuel=43MJ/kg, rise in cooling water temperature=45oC,

cooling water flow rate = 4.5kg/min, temperature of exhaust gas = 420oC, mean specific heat

of exhaust gas=1kJ/kg-oK, room temperature=20

oC, specific heat of water=4.18kJ/kg-

oK, air

used per kg of fuel=30kg. Draw up a heat balance sheet in kJ/hr and estimate indicated power

and brake Power.

OR

5) a) Explain Morse test.

b) What are the limitations of Motoring test?

Unit -III

6) a) What is delay period? Discuss the factors that affect the delay period.

b) Explain any one open type of combustion chambers used in C.I. engines with

sketch.

OR

7) a) What is slip factor? What is its effect on the flow and the pressure ratio in

the stage?

b) Compare the merits and demerits of axial flow compressors and centrifugal

compressors.

Unit -IV

8) a) Draw the schematic lay out of gas turbine cycle with regenerator,

intercooler and reheating. Explain salient features.

b) The minimum and maximum temperature limits in a gas turbine plant are

288oC and 1100

oC. The pressure limits are 1 bar and 8 bar. Determine the

thermal efficiency and work ratio.

OR

9) a) What do you mean by jet propulsion? Explain the various devices in a jet

propulsion unit.

b) What is ram jet? Explain the working of ramjet with a neat sketch.

� � �

(DME 316)

B.Tech. DEGREE EXAMINATION, DEC. 2013

(Examination at the end of Third Year)(Third Semester)


Paper – VI : METAL CUTTING & MACHINE TOOLS


Answer Question No.1is compulsory

Answer One question from each unit

1) Write a short note on the following

a) Explain the working principle of a machine tool.

b) Explain taper turning.

c) What is drilling time ?

d) Explain quick return mechanism in shaper.

e) Explain honing operation.

f) Explain Universal milling machine.

g) Explain chip thickness ratio.

UNIT - I

2) a) Explain the dynamic characteristics for metal cutting process.

b) Which are two popular metal cutting theories ? Describe them.

OR

3) a) Explain with neat sketch how thread cutting operation is done on by lathe.

b) Why turning is required on surfaces ? How it is produced on a lathe ?

UNIT – II

4) a) Explain with a neat sketch the construction and working principle of a radial

drilling machine.

b) What are various operations performed on shaper ? Explain.

OR

5) a) Explain abrasive belt grinding.

b) What are the advantages and disadvantages of centre less grinding ?

UNIT – III

6) a) How is milling machine specified ?

b) What are the machining operations can be done on a milling machine.

OR

7) a) Sketch and describe the working of a drum-type milling machine.

b) What are the differences between compound indexing and differential

indexing ?

UNIT – IV

8) a) What are the forces acting on a single point tool as it is engaged to cut?

b) Explain the mechanics of chip formation.

OR

9) a) What are the essential properties of cutting fluids ? Explain.

b) Why tool wear is important in metal cutting ?

��

(DME321)


(Examination at the end of Third Year Fourth Semester)


Paper - I : OPERATIONS MANAGEMENT


Answer Question No.1 is compulsory. (15)

Answer ONE question from each unit. (4×15 = 60)

1) Write a brief note on the following.

a) Batch production.

b) Aggregate planning.

c) Scheduling.

d) Inventory control.

e) VED Analysis.

Unit- I

2) Briefly explain the methods of forecasting.

OR

3) What is a production system? Explain the different types of production systems.

Unit - II

4) Explain the objectives and functions of master production schedule.

OR

5) Explain the importance of variable control charts and also explain different types

of control charts.

Unit - III

6) What is meant by Economic Order Quantity? What are the models of EOQ.

OR

7) Enumerate the significance of CRP.

Unit - IV

8) a) What is a control chart? What are the benefits of using control charts? Also

explain the different types of control charts.

b) Discuss the importance of reliability.

OR

9) What is multi sampling? Discuss with examples.

� � �

(DME 322)

B.Tech. DEGREE EXAMINATION, DEC. 2013

(Examination at the end of Third Year)(Fourth Semester)

MECHANICAL ENGINEERING

Paper – II : Design of Transmission Elements


Answer Question No.1 compulsory

Answer ONE question from each Unit

(5 x 3 = 15)

(4 x 15 = 60)

1) a) Define Equivalent Bending moment and write an expression for hollow shaft.

b) What is “Needle Bearing”? Give their application.

c) Write the advantages of chain drives over belt drives.

d) Classify the different types of gears.

e) What is the relationship between actual and virtual number of teeth in bevel

gears.

UNIT – I

2) A shaft is supported on bearings A and B, 800mm between centre’s. A 20O

straight tooth spur gear having 600mm pitch diameter, is located 200mm to the

right of the left hand bearing A, and a 700mm diameter pulley is mounted 250mm

towards the left of bearing B. The gear is driven by a pinion with a downward

tangential force while the pulley drives a horizontal belt having 180O angle of

wrap. The pulley also serves as a flywheel and weighs 2000 N. The maximum belt

tension is 3000 N and the tension ratio is 3:1. Determine the maximum bending

moment and the necessary shaft diameter if the allowable shear stress of the

material is 40 MPa.

OR

3) Design and draw a protective type of cast iron flange coupling for a steel shaft

transmitting 15kW at 200 r.p.m. and having an allowable shear stress of 40 MPa.

The working stress in the bolts should not exceed 30 MPa. Assume that the same

material is used for shaft and key and that the crushing stress is twice the value of

its shear stress. The maximum torque is 25% greater than the full load torque. The

shear stress for cast iron is 14 MPa.

UNIT – II

4) Design a suitable journal bearing for a centrifugal pump from the following

available data: Load on the bearing = 13.5 kN; Diameter of the journal = 80mm;

Speed = 1440 r.p.m.; Bearing characteristic number at the working temperature

(750C) = 30; Permissible bearing pressure intensity = 0.7 N/mm

2; Average

atmospheric temperature = 300C. Calculate the cooling requirements, if any.

OR

5) A ball bearing subjected to a radial load of 4000 N is expected to have a

satisfactory life of 12000 hours at 720 r.p.m. with a reliability of 95%. Calculate

the dynamic load carrying capacity of the bearing, so that it can be selected from

manufacturer’s catalogue based on 90% reliability. If there are four such bearings

each with a reliability of 95% in a system, what is the reliability of the complete

system.

UNIT - III

6) A 8mm thick leather open belt connects two flat pulleys. The smaller pulley is

300mm diameter and runs at 200 r.p.m. The angle of lap of this pulley is 1600 and

the coefficient of friction between the belt and the pulley is 0.25. The belt is on

the point of slipping when 3kW is transmitted. The safe working stress in the belt

material is 1.6 N/mm2. Design the drive for 20% overload capacity.

OR

7) Design a chain drive to run a blower at 600 r.p.m. The power to the blower is

available from a 8kW motor at 1500 r.p.m. The centre distance is to be kept at 800

mm.

UNIT – IV

8) Design a cast iron spur gear drive for a crane hoist to transmit 3.75 kW at 1440

rpm. Maximum gear ratio in the gear box is 4. Each gear is expected to work 2

hours/day for 10 years. Determine the minimum centre distance, required face

width and module of the gear.

OR

9) A single stage helical gear reducer is to receive power from a 1440 r.p.m., 25kW

induction motor. The gear tooth profile is involutes full depth with 200 normal

pressure angle. The helix angle is 230, number of teeth on pinion is 20 and the

gear ratio is 3. Both the gears are made of steel with allowable beam stress of 90

MPa and hardness 250 B.H.N.

a) Design the gears for 20% overload carrying capacity from standpoint of

bending strength and wear.

b) If the incremental dynamic load of 8kN is estimated in tangential plane, what

will be the safe power transmitted by the pair at the same speed?

��

(DME323)




Paper - III : MECHANICAL VIBRATIONS


Answer Q.1 is compulsory (15)

Answer ONE question from each unit. (4 X 15 = 60)

1) a) Differentiate natural and forced vibrations.

b) What are the different types of damping.

c) What is seismic instrument and explain it.

d) What is vibration isolation.

e) Write about Dunkerley’s method.

UNIT - I

2) A spherical body of radius r rolls without slipping on a concave spherical surface

of radius R. Find the frequency of small vibrations of the sphere about the

equilibrium position.

OR

3) Find the natural frequency of vibration for the system shown in Fig. 1 Neglect

the mass of the bar AB.

UNIT - II

4) A gun barrel of mass 600Kg has recoil spring of stiffness 294000 N/m, barrel

recoils 1.3 m on firing determine.

a) The initial recoil velocity of the barrel.

b) The critical damping coefficient of the dashpot which is engaged at the

end of the recoil stroke, and

c) The time required for the barrel to return to a position 5 cm from the

initial position

OR

5) A vertical spring of stiffness 9800 n/m supports a mass of 40Kg .There is a

friction force of 49N which always resist the vertical displacement whether

upwards or downwards. The mass is released from a position in which the total

extension of the spring is l2.6cm. Determine the final extension of the spring in

the position in which system comes to rest.

UNIT - III

6) A commercial type of vibration pick-up has a natural frequency of 5.75Hz and a

damping factor of 0.65. What is the lowest frequency beyond which amplitude

can be measured within l% and 2% errors.

OR

7) For the two degree of freedom system shown in below find the lowest natural

frequency using stodola’s method.

UNIT - IV

8) Determine the characteristic equation for a beam pinned at one end and free at

the other end. Treat the beam as a continuous system. Take the length of the

beam as L.

OR

9) Find the lowest natural frequency of transverse vibrations for the system shown

in below by Rayleigh’s method

E = 1.96 x l011

N/m2; I = 4.0 x 10

-7m

4.

��

(DME 324 )




Paper - IV : BASIC ELECTRONICS &MICROPROCESSORS


Answer Question No.1 is compulsory (15)

Answer One question from each unit (4×15=60)

1) a) What is Potential Barrier?

b) What is pure intrinsic semiconductor?

c) What is the Peak inverse voltage of half wave rectifier?

d) What is meant by avalanche breakdown?

e) What are barkhausen criteria?

f) What is Excess-3 code?

g) List of the applications of colpitt’s oscillator?

h) What is ALP?

i) What are the general purpose registers in 8085?

UNIT -I

2) a) Explain the UJT as a relaxation oscillator.

b) What do you understand by transistor biasing and explain how stability can

be achieved in a self bias transistor circuit?

OR

3) a) Compare the differences between JFET and MOSFET?

b) Obtain the output voltage expression for a full-wave bridge rectifier circuit?

UNIT -II

4) a) Explain the principles of oscillators indicating the function of various

components.

b) Explain the working of op-amp differentiator circuit.

OR

5) a) Draw the circuit of Wien Bridge oscillator and explain the principle of

operation.

b) Derive the expression for its frequency of oscillatons. What is the condition

on ‘β’ for getting sustained oscillations?

UNIT -III

6) a) Express the following function in product of maxterms.

F(u,v,w,x)=v’x+u’x+vx.

b) Obtain simplified POS expression for the following function using K-map.

f(A,B,C,D) = ∑m (0,1,2,6,8,10,11,12)

OR

7) a) Explain different number systems and the procedure of converting one

number system into other with a suitable example.

b) Explain the operation of a bidirectional shift register.

UNIT -IV

8) Explain PIN diagram of 8085 clip indicating its various functions.

OR

9) a) Explain addressing modes of 8085.

b) Write short notes on interfacing 8085 to input and output devices.

� � �

(DME325)




Paper - V : HEAT TRANSFER

Time: 03 Hours Maximum Marks: 75

Answer Question No.1 is Compulsory (15)

Answer any ONE question from each unit (4 × 15 = 60)

1) a) What is the necessity of study of heat transfer when quantity of heat

transferred can be found from laws of Thermodynamics.

b) State Fourier’s law of heat conduction

c) Define overall heat transfer coefficient ‘U’.

d) Write Colburn’s analogy.

e) What are regimes of pool boiling.

f) Define emissivity of thermal radiation.

g) State Reciprocity theorem of thermal radiation.

2) a) Write the Fourier rate equation for heat transfer by conduction. Give the

physical significance of each term.

b) Determine the steady heat transfer per unit area through a 3.8 cm thick

homogeneous slab with its two faces maintained at uniform temperatures of

350C and 250C. The thermal conductivity of wall material is 1.9x10-4

kW/m-

K.

OR

3) A hot gas at 573 K ows through a long metal pipe of 0.1m OD and 0.003m thick.

From the stand point of safety and of reducing heat loss from the pipe,

mineral wool insulation (k=0.052W/m K) is wrapped around so that the exposed

surface of the insulation is at a temperature of 323 K. Calculate the thickness of

insulation required to achieve this temperature if hi=29W/m2 K, ho=11.6W/m

2 K

and the surrounding air temperature in 298 K. Also calculate the corresponding

heat transfer rate per unit length.

UNIT - II

4) A long steel cylinder 12cm in diameter and initially at 20oC is placed into a

furnace at 820oC where the heat transfer coefficient, h=140 W/m

2 K. Calculate the

time required for the axis temperature to reach 800oC. Calculate also

a) The corresponding temperature at a radius of 4.8 cm at that time and

b) The heat energy absorbed by the cylinder during this period, given that the

thermal diffusivity, α = 6.11x106 m

2/s and the thermal conductivity,

k=21W/m.K.

OR

5) a) Explain the Reynold’s Analogy in forced convection.

b) Water ows inside a smooth tube at a mean ow velocity of 3.0 m/s. The tube

diameter is 25mm and constant heat flux condition is maintained at the tube

wall such that the tube temperature is always 200c above the water

temperature. The water enters the tube at 300c and leaves at 500C. Calculate

the tube length necessary to accomplish the indicated heating.

UNIT – III

6) a) What is the criterion for transition from laminar to turbulent boundary layer

in free convection on a vertical at plate.

b) Estimate the electrical power required to maintain a vertical heater surface at

1300C in ambient air at 200C. The plate is 15cm high and 10cm wide.

Consider equivalent radiation heat transfer coefficient as 8.5 W/m2K.

OR

7) a) Write short notes on LMTD.

b) Hot oil is to be cooled by water in a one shell pass and eight tube passes heat

exchanger. The tubes are thin walled and made of copper with an internal

diameter of 14mm. The length of each tube pass is 5m and Uo=310 W/m2K.

Water flows through the tubes at a rate of 0.2kg/s and the oil through the

shell at a rate of 0.3 kg/s. The water and the oil enter at temperatures of 20oC

and 150oC respectively. Determine the rate of heat transfer and the exit

temperatures of the water and the Oil.

UNIT - IV

8) a) Explain the utility of radiation shields.

b) Two large parallel planes having emissivities 0.3 and 0.5 are maintained at

temperatures of 900oC and 400

oC respectively. A radiation shield having an

emissivity of 0.05 is placed between the two planes. Estimate:

i) Heat exchange per m2 of area if the shield were not present,

ii) Temperature of the shield, and

iii) Heat exchange per m2 area when the shield is present.

OR

9) a) Explain the terms absorptivity, reactivity and transmissivity.

b) Fused quartz transmits 90% of the incident thermal radiation between 0.2

and 4 µm. Suppose a certain heat source is viewed through the quartz

window, what heat flux in Watts will be transmitted through the material

from black body radiation sources at:

i) 800oC

ii) 550oC

��

(DME 326)

B. Tech. DEGREE EXAMINATION, DEC. - 2013



Paper – VI: ENGINEERING METROLOGY


Answer Question No.1 compulsory. (15)

Answer ONE Question from each Unit. (4X15=60)

1) a) Explain the terms shrinkage fit and forced fit.

b) Explain the terms sensitivity.

c) Name the three materials commonly used for gauges.

d) What is a comparator? Classify.

e) What are the various types of pitch errors on the thread component?

f) What are the sources of Errors in manufacturing gears?

g) Write advantages of CMM.

Unit - I

2) a) Explain the term interchangeability.

b) Describe briefly any system of limits and fits for engineering production.

c) Define terms: tolerance, allowance and limits.

OR

3) Explain Taylor’s principal. What are the considerations for deciding the limits on

the limits gauges?

Unit – II

4) Explain the principal six point location with neat sketch.

OR

5) What are the elements of gears which are checked for accuracy? Describe a gear

tooth-vernier caliper and show how this is used for checking gears.

Unit – III

6) Describe a pitch measuring machine. Explain how the various elements of internal

threads are measured.

OR

7) With neat sketch explain the working of Solex pneumatic gauge.

Unit – IV

8) How the Tomlinson surface recorder and Talysurf machine work? What are their

relative merits?

OR

9) Distinguish between alignment test and performance test of a machine tool.

Discuss with neat sketches how would test chuck run-out and cross slide

alignment.

E E EE E EE E EE E E

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