iii yr me - anucde · (dme 312) b.tech. degree examination, nov./dec. - 2014 (examination at the...

(DME 311)

B.Tech. DEGREE EXAMINATION, NOV./DEC. - 2014

(Examination at the end of Third Year Third Semester)

MECHANICAL ENGINEERING Paper – I: Operations Research

Time : 3 Hours Maximum Marks : 75

Question No.1 is compulsory (15)

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

1) Write short notes on:

a) Limitations of operations research.

b) Unbounded solution.

c) Vogel’s approximation.

d) Arrow Diagram.

e) Min-max principle.

UNIT-I

2) Describe model building in operations Research in detail.

OR

3) Explain Graphical method and infeasible solution.

UNIT-II

4) Give a brief explanation on transportation problem.

OR

5) Show that how can Queing theory is done in different models.

UNIT-III

6) Explain Arrow Diagram representation in detail.

OR

7) Explain Pert and CPM and Critical Path calculations.

UNIT-IV

8) 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 the characteristics of D.P model.

b) Limitations of operations research.

E E E

(DME 312)



MECHANICAL ENGINEERING Paper – II: Design of Machine Elements


Question No.1 is compulsory (15)


1) Write a short note on the following:

a) Standardization in design.

b) Preferred numbers and their significance.

c) Importance of factor of safety in design.

d) Goodman diagram.

e) Types of power screws.

UNIT-I

2) a) What is factor of safety? Why is it necessary? Why a very small or a large factor of

safety should not be used?

b) Explain types of designs in machine elements.

OR

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

5 kN. Find the diameter of the bolt required with respect to

a) Maximum strain energy theory.

b) Max. principal stress theory

Take permissible tensile stress at elastic limit = 100 MPa and poission’s Ratio = 0.3.

UNIT-II

4) a) Discuss various methods of reducing stress concentration.

b) A pulley is keyed to a shaft midway between two antifriction bearings. The bending

moment at the pulley varies from 250kN-m to 750 kN-mm and the torsional moment

in the shaft varies from 100 kN-mm to 300 kN-mm. The frequency of the variation

of the load is same as the shaft speed. The shaft is made of cold drawn steel having

an ultimate strength of 550 N/mm2 and yield strength of 450N/mm2. Determine the

required diameter for an infinite life. The stress concentration factor for the key way

in bending and torsion may be taken as 1.8 and 1.5 respectively. The factor of safety

is 2.0. Take size factor = 0.85 and surface finish factor = 0.88.

OR

5) Explain the design procedure for fluctuating stresses.

UNIT-III

6) Design a triple riveted double cover plate with unequal cover plates butt joint for

logitudinal seam of a boiler if the inside diameter of largest course of the drum is 1m and

steam pressure is 1.9 MPa. Assume the allowable stresses as = 60 MPa. t = 80 MPa &

c = 130 MPa.

OR

7) Explain the design procedure for eccentrically loaded welded joints.

UNIT-IV

8) Design a sleeve and cotter joint to resist a tensile load of 50 kN. Assume the stresses as

follows: = 55 MPa, t = 65 MPa & c = 140 MPa. Draw the freehand sketch of the joint

showing important dimensions.

OR

9) Explain the design procedure for joints under eccentric loading.

E E E

(DME 313)



MECHANICAL ENGINEERING Paper – III : Machine Dynamics


Answer question No.1 is compulsory (15)



a) Four – link mechanism.

b) Dynamic Balancing.

c) Distinguish between absorption and transmission dynamometers.

d) Controlling force in governor.

e) Gynoscopic couple.

UNIT-I

2) a) What is meant by a dynamically equivalent system.

b) Explain the slides crank mechanism.

OR

3) Determine the required input torque on the crank of a slides – crank mechanism for the

static – equilibrium when the applied piston load is 1500N. The lengths of the crank and

the connecting rod are 40 mm and 100 mm respectively the crank has turned through 45o

from the inner dead centre.

UNIT-II 4) Two weights of 8 kg and 16 kg rotate in the same plane at radii of 1.5 and 2.25m

respectively. The radii of these weights are 60o a part. Find the position of the third weight

of the magnitude of 12 kg in the same plane which can produce static balance of the

system.

OR

5) The pistons of a 60o twin V – engine has strokes of 200 mm. The mass of the reciprocating

parts per cylinder is 1 kg and the speed of the crank shaft is 2500 rpm. Determine the

magnitude of the primary and secondary forces.

UNIT-III

6) Explain the types of Belt transmission dynamometers.

OR

7) The moment of Inertia of an aeroplane oil screw is 20 kg – m2 and the speed of rotation is

1000 rpm clock wise when viewed from the front. The speed of the flight is 200 km per

hour. Find the gyroscopic reaction of the air screw on the aeroplane when it makes a left –

handed turn on a path of 150m radius.

UNIT-IV

8) Explain the working of porter Governor with neat sketch.

OR

9) a) Justify the proell Governor is better than porter Governor.

b) Explain the significance of sensitiveness of a Governor.

E E E

(DME 314)


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

MECHANICAL ENGINEERING Paper – IV : Hydraulic Machines




1) Write a short notes on the following:

a) Classification of fluid machines.

b) Draft tube theory.

c) Pump losses.

d) Hydraulic accumulator.

e) Model laws.

UNIT-I

2) Show that when a jet of water Impinges on a series of curved vanes, maximum efficiency

is obtained when the vane is semi – circular in section and the velocity of a vane is half of

that jet.

OR

3) A 7.5 cm diameter jet having a velocity of 30 m/s strikes a flat plate, the normal of which

is inclined at 45o to the axis of the jet. Find the normal force exerted on the plate.

a) When plate is stationary.

b) When plate is moving with a velocity of 15 m/s in the direction of jet away from the jet.

c) Also determine the power and efficiency of system when the plate in moving.

UNIT-II

4) a) Compare and constrast impulse and reaction turbines.

b) A Kaplan turbine working under a head of 15m develops 7357.5 kw shaft power. The

outer diameter of the runner is 4m and hub diameter 2m. The guide blade angle at the

extreme edge of the runner is 30o. The hydraulic and overall efficiencies of the

turbine are 90% and 85% respectively. If the velocity of whirl is zero at outlet,

determine:

i) Runner vane angles at inlet and outlet at the extreme edge of the runner and

ii) Speed of the turbine. OR

5) A pelton wheel working under a head of 500m has an overall efficiency of 85% and runs at

400 rpm, and develops 7000 kw of power. Taking the bucket speed as 0.47 times the jet

speed and assuming Cv = 0.97 find

a) The wheel diameter and

b) The jet diameter. Assume any other data if necessary.

UNIT-III

6) a) What are multistage centrifugal pumps? Compare them with pumps arranged in

parallel.

b) Discuss the following of a centrifugal pump

i) Main characteristics curves. ii) Operating characteristic curves.

iii) Constant efficiency curves. iv) NPSH.

OR

7) a) Explain condition in which two pumps may be operated in series or in parallel.

b) What is a multistage pump and what are its advantages.

UNIT-IV

8) With suitable sketch explain hydraulic ram. List different types of Hydraulic rams.

OR

9) a) Explain Froude laws.

b) Types of models – Discuss.

E E E

(DME 315)



MECHANICAL ENGINEERING Paper – V: I.C. Engines and Gas Turbines




1) a) Draw a line sketch of C.I. Engine and name the parts.

b) What is a carburettor? State the limitations of simple carburettor.

c) What is the importance of specific fuel consumption?

d) Define the combustion?

e) Draw the P- diagram for C.I. engine.

f) Differentiate between positive displacement type and dynamic rotary compressors.

g) State the advantages and disadvantages of gas turbines over IC engines.

UNIT-I

2) a) What is meant by cylinder row and cylinder bank.

b) With neat sketches explain the working principle of four – stroke spark – ignition

engine.

OR

3) a) List out the limitations of simple carburetor and explain how these are over come in

modern carburetors.

b) With a simple layout explain the Bosch K Tentronic injection system.

UNIT-II

4) a) What is the importance of specific fuel consumption.

b) A four cylinder engine running at 1200rpm delivers 20 kw. The average torque when

one cylinder was art is 110 N-m. Find the indicated thermal efficiency if the calorific

value of the fuel is 43 MJ/kg and the engine uses 360 grams of gasoline per kwh.

Calorific value of fuel is 43000 kJ/kg.

OR

5) a) Explain the difference between gross calorific value and net calorific value.

b) The volumetric analysis of a fuel gas is: CO2 = 14%; CO = 1% O2 = 5% and N2 =

80%. Calculate the fuel gas composition by weight.

UNIT-III

6) Bring out clearly the process of combustion in C.I. engines and also explain the various

stages of combustion.

OR

7) a) What is a centrifugal compressor? How does it differ from an axial flow compressor?

b) What is a slip factor and a pressure co-efficient? Explain.

UNIT-IV

8) a) Describe with neat sketches the working of a simple constant pressure open cycle gas

turbine.

b) Enumerate the various uses of gas turbines.

OR

9) a) What do you mean by jet propulsion ? State the fundamental difference between the

jet propulsion and rocket propulsion.

b) Explain the thrust power propulsive efficiency and Thermal Efficiency.

E E E

(DME 316) B.Tech. DEGREE EXAMINATION, NOV. / DEC. - 2014


MECHANICAL ENGINEERING

Paper-VI : Metal Cutting & Machine Tools


Answer Question No. 1is compulsory. (15)

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

1) a) What are the functions of a machine tool?

b) How is the size of a lathe specified?

c) List the common lathe operations which can be carried out on a lathe.

d) What is the function of a drilling machine?

e) Principle of shaper.

f) What is superfinishing?

g) Different tool materials.

UNIT-I

2) a) Explain briefly the parts of a Lathe.

b) Determine the time taken to turn a 50mm diameter by 70mm long workpiece of

the cutting speed is 45m/min and the feed is 0.5mm/revolution. One cut is to

be considered.

OR

3) a) What are the differences between a turret lathe and a capstan lathe?

b) Determine the time taken to face a workpiece of 72mm diameter. The spindle

speed is 80 rpm and crossfeed is 0.3 mm/revolution.

UNIT-II

4) a) What is the difference between ‘counter boring’ and ‘counter sinking’ operations?

b) How are the machining time and material removal rate in a drilling machine calculated?

OR

5) a) Discuss the working principle and operation of a shaper.

b) Explain briefly with neat sketches various types of grinding machines.

UNIT-III

6) Explain about universal milling machine. List its advantages and limitations.

OR

7) With neat sketches explain about various operations performed on milling machine.

List their applications.

UNIT-IV

8) a) Explain the nomenclature of single point cutting tool.

b) Give the comparison between ‘orthogonal cutting’ and ‘oblique cutting’.

OR

9) a) On what factors does the tool life depend?

b) What are the requirements of a cutting fluid?

c) What are the characteristics of an ideal cutting-tool material?

● ● ● ● ●


(Examination at the end of Third Year Fourth Semester)


Paper - I : Operations Management


Answer any Five of the following.

All questions carry equal marks.

1) Explain the merits of linear regression and correlation coefficient methods of

forecasting.

2) Give an account of different kinds of production systems.

3) Bring out mathematical models of planning.

4) Describe the formation of master scheduling.

5) Enumerate the functions of materials management.

6) Elucidate the importance of MRP and CRP.

7) How are safety and buffer stocks fixed?

8) Explain the multisampling plans for attributes.

9) What are the factors that affect reliability?

10) Describe the uses of control charts for variables.

● ● ● ● ●




Paper-II : Design of Transmission Elements


Question No. 1is compulsory. (15)



a) Types of Lubrications.

b) Types of Bearings.

c) Selection of pulleys.

d) Lewis equation in Helical gears.

e) Terminology in worm gears.

UNIT-I

2) Explain the design procedure of hollow shafts under torsion and axial loads.

OR

3) a) Explain the procedure for square key design.

b) A medium carbon steel shaft transmits 25kw at 450 rpm. The diameter of shaft is 40mm. A square key is used whose one side is equal to 1/4th the shaft diameter and whose length is equal to 1-5 times the shaft diameter. Find the dimensions of the key and check the key for the induced shearing stress and crushing stress.

UNIT-II

4) a) Discuss in detail about materials and applications of journal bearing.

b) A journal bearing 150mm diameter and 300mm long carries a radial load of 9kN at 1200 rpm. The diametral clearance is 0.075mm. If 6kw is being lost in friction, what is the viscosity of the oil used at given operating temperature.

OR

5) Explain the selection procedure of ball and roller bearings.

UNIT-III

6) A V-belt drive is to be arranged between two shafts with 1.2m as centre distance.

The driving pulley is of 250mm diameter and is to be supplied with 20 kw power at

960 rpm. The follower pulley is to run at 460 rpm.

Determine the number of belts required from the following:

Area of belt cross section = 143 mm2

Mass density of the belt material = 1000 kg/m3

Permissible tensile stress = 2 N/mm2

Coefficient of friction = 0.3

Groove angle of the pulley = 40o

OR

7) a) Explain different types of chain drives.

b) List the advantages of chain drives over belt drives.

UNIT-IV

8) a) Define i) axial pitch of the worm ii) lead of the worm and

iii) lead angle of the worm, as applicable to worm gearing.

b) Explain briefly strength design of worm gear teeth, wear load capacity of a

worm drive with suitable equations.

OR

9) A cast iron helical gear with 30o helix angle has to transmit 20kw at 1200 rpm. The

safe static stress for cast iron is 55 MPa. The width of face is 3.5 times circular

pitch. If the gear has 24 teeth determine the following for 20o full depth teeth.

a) Module

b) Pitch diameter

c) Width of face

d) Indth rust, assume lubrication factor = 1.15.

● ● ● ● ●




Paper-III : Mechanical Vibrations


Answer Question No. 1 is compulsory. (15)


1) a) Explain Beats phenomenon.

b) What is stiffness of spring?

c) Discuss logarithmic decrement.

d) Rayleigh-Ritz method.

e) Types of damping.

UNIT-I

2) a) What effect does a decrease in mass have on the frequency of a system?

b) A cylinder of mass M radius r rolls without slipping on a cylindrical surface of

radius R. Find the natural frequency for small oscillation about the lowest point.

OR

3) a) Define the terms generalized impedance and admittance of a system.

b) Find the steady state response of undamped single degree freedom system

subjected to the force F(t) = Fo eiwt by using the method of Laplace

transformation.

UNIT-II

4) A machine mounted on springs and fitted with a dashpot has a mass of 60kg. There

are three springs, each of stiffness 12 N/mm. The amplitude of vibrations reduced

from 45 to 8 mm in two complete oscillations. Assuming that the damping force

varies as the velocity determine

i) The damping coefficient.

ii) The ratio of frequencies of damped and undamped vibrations and

iii) The periodic time of damped vibrations.

OR

5) Derive an expression for determining the critical speed of a light shaft having a

single disk without damping.

UNIT-III

6) a) What are vibration absorbers? Explain the working principle of a centrifugal

pendulum vibration absorber with the help of a neat sketch.

b) For damped free vibration system, derive the equation for amplitude for over-

damped and critically damped system.

OR

7) A cantilever shaft 50mm diameter and 300mm long has a disc for mars 100kg at its

free end. The Young’s modulus for the shaft material in 200 GN/m2. Determine the

frequency of longitudinal and transverse vibrations of the shaft.

UNIT-IV

8) a) How is the frequency equation derived for a multi degree of freedom system.

b) For a taut string having tension T and three concentrated masses as shown

below, use the method of influence numbers to find the three natural

frequencies. Find also the mode shapes. Check on the orthogonal properties of

the normal modes.

OR

9) Explain the multidegree of freedom system using Dunkerley’s method.

● ● ● ● ●




Paper-IV : Basic Electronics & Microprocessors


Answer Question No. 1is compulsory.


1) a) How does a zener diode work in forward bias condition draw VIchs in forward

bias condition. (2)

b) Define α and β of a BJT. (2)

c) Give the ideal operational amplifier characteristics. (2)

d) What is a multivibrator. (2)

e) (FB81)16 = ( )8 = ( )10. (2)

f) What is a latch? (1)

g) Draw a SR flip flop. (2)

h) What does HALT and JUMP instructions perform. (2)

UNIT-I

2) a) Draw and explain the input and output characteristics of BJT in CE

configuration.

b) Explain the VI characteristics of JFET.

OR

3) a) Explain how a zener diode can be used as a voltage regulator.

b) Explain the action of a transistor as an amplifier.

UNIT-II

4) a) Explain the working of a Wien bridge oscillator using neat figures.

b) How does an op amp work as an integrator and differentiator.

OR

5) a) With a neat sketch explain the operation of a Bistable multivibrator.

b) Explain the working of a Colpitts oscillator.

UNIT-III

6) a) Explain the working of a half adder with the help of truth table.

b) Draw and explain a JK flip flop.

OR

7) a) Give the significance of semi conductor memories.

b) Explain the working of a multiplexer.

UNIT-IV

8) a) Explain the addressing modes of 8085.

b) Write a program to multiply two 8 bit numbers.

OR

9) a) Explain the Instruction set of 8085.

b) Write a program to subtract two given numbers.

● ● ● ● ●




Paper-V : Heat Transfer


Question No. 1 is compulsory. (15)



a) Differentiate between the thermodynamics and Heat Transfer.

b) What is Stefan’s Boltzmann law?

c) Define Biot number. What is the significance of this number.

d) State the Navier-Stokes education.

e) Define Grashof number and explain its significance in free convection heat

transfer.

f) Define overall heat transfer co-efficient ‘U’.

g) Define the terms absorptivity, reflectivity and transmittivity of radiation.

UNIT-I

2) a) Explain the electrical analogy of heat transfer. Illustrate the concept of

electrical analogy considering a multilayer composite wall.

b) Consider a 4m 6m 0.3m thick brick wall whose k = 0.8 W/mK. The

temperature of inner and outer surfaces of the wall are measured to be 45oC

and 25oC respectively. Find the rate of the heat transfer through the wall.

OR

3) a) Derive the general heat conduction educations systems and hence deduce the

expression for temperature distribution through a plane wall.

b) Consider a 1.2m 2m glass window of 6mm thick having k = 0.75 W/mK,

which is exposed to environment at 20oC with a convective heat transfer co-

efficient of 10 W/m2K. If the inner surface temperature of the glass is at 5oC.

Find the outer surface temperature and rate of heat leak into the room.

UNIT-II

4) a) Distinguish between steady state and unsteady state conduction.

b) A long aluminium cylinder 5.0cm in diameter and initially at 200oC is suddenly

exposed to a convection environment at 70oC and h = 525 W/m2k. Calculate

the temperature at a radius of 1.25cm, 1 min after the cylinder is exposed to the

environment.

OR

5) a) Explain Reynolds analogy and cal burn analogy.

b) Air at a temperature of 30oC flows over a flat plate of length 1m and width 2m

with a velocity of 3 m/s. Determine the direction of air i.e; along its length or

width that will create maximum drag force.

UNIT-III

6) a) Explain the difference between parallel flow and counterflow heat exchangers

and show how the temperature of the two fluids vary along the path of flow.

b) In a food processing plant a brine solution is heated from 12oC to 6.5oC in a

double pipe parallel flow heat exchanger by water entering at 35oC and leaving

20.5oC at the rate of 9 kg/min. Determine the heat exchange area for an overall

heat transfer co-efficient of 860 W/m2K. For water Cp = 4.186 kJ/kg K.

OR

7) a) Discuss various theoritical and empirical educations available to predict natural

convection heat transfer co-efficient.

b) The outer surface of a vertical is tube which is of length 1.25m and outer

diameter 50mm is exposed to saturated steam at atmospheric pressure. The

surface is maintained at 80oC by the flow of cooling water through it.

Determine the rate of heat transfer to the coolant and the rate at which the

steam is condensed at the tube surface. If the tube is held in horizontal

position, will there be any change in the mass of condensate.

UNIT-IV

8) a) What is shape factor with respect to itself if the surface is concave, convex or

flat?

b) A room measuring 3m 4m 2m high has the ceiling covered with heating

panels. Under steady state conditions, the ceiling is at a temperature of 50oC

and the walls and floor at a temperature of 20oC. Assuming all the surfaces

have an absorptive of units, calculate the net radiant heat transfer from the

ceiling.

OR

9) a) State and prove Kirchoff’s law. What are the limitations to use it?

b) A black body is maintained at 200oC. Calculate i) Total emissive power ii)

Wave length at which maximum monochromatic power occurs and iii)

Maximum monochromatic emissive power.

● ● ● ● ●




Paper-VI : Engineering Metrology


Answer Question No. 1is compulsory. (15)



a) Types of Fits.

b) How do you calibrate the slip gauges.

c) Principle of limit gauges.

d) Indexing jig.

e) Sources of errors in gear manufacturing.

f) Application of Tool makers microscope.

g) Advantages of CMM.

UNIT-I

2) a) Distinguish between straightness and flatness. List out the methods of

measuring each of these.

b) What are the different elements of engineering measurements?

OR

3) a) Explain about angle gauges and its applications.

b) Explain with sketch, how sine bar can be used to measure a taper angle.

UNIT-II

4) Explain the design considerations while selecting jigs & fixtures.

OR

5) a) Explain the gear shaping principle and its advantages.

b) Describe a gear tooth-vernier calliper and show how this is used for checking

gears.

UNIT-III

6) a) Define ‘effective diameter’ and ‘best size wire’, derive an expression to

determine the best size wire diameter.

b) Explain with sketch the principle and working of an auto collimator.

OR

7) With the help of sketch describe how tool maker’s microscope can be used to

measure the elements of screw threads.

UNIT-IV

8) Explain various methods of measuring surface finish.

OR

9) Explain various instruments required for performing the alignment tests on machine

tools.

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iii yr me - anucde · (dme 312) b.tech. degree examination, nov./dec. - 2014 (examination at the...

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