# DME autocollimator by mikeholy

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```									                                                                               (DME 311)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper I — OPERATIONS RESEARCH

Time : Three hours                                                       Maximum : 75 marks

Answer Question No. 1 compulsorily.          (1  15 = 15)

Answer ONE question from each Unit.           (4  15 = 60)

All questions carry equal marks.

1.   Write brief note on :
(a)   Basic solution of a LPP.
(b)   Duality.
(c)   Various types of O.R. models.
(d)   Use of two phase method in solving a LP problem.
(e)   Differences between transportation and assignment problems.
(f)   Basic characteristics of queue system.
(g)   Unbalanced transportation problem.
(h)   Critical path in PERT/CPM.
(i)   Normal time and expected time in PERT.
(j)   Crash duration.
(k)   Characteristics of queuing system.
(l)   Two person zero sum game.
(m) Applications of game theory in marketing.
(n)   Dominance property in game theory.
(o)   What is Line of Balance?

UNIT I

2.   Solve by Simplex method :
Max. Z  10 x1  15 x 2  20 x 3

Subject to : 10.7 x1  5 x 2  2 x 3  2705
5.4 x1  10 x 2  4 x 3  2210
0.7 x1  x 2  2 x 3  445
x1 , x 2 , x 3  0 .
Or

3.   (a)   Solve the following LPP graphically :

Max. Z  2 x1  x 2

Subject to : 3 x1  2 x 2  12
x1  2 x 2  7
x1  x 2  5
x 1 , x 2  0.

(b)   Solve the LPP by applying the principle of duality :

Min. Z  2 x1  2 x 2

Subject to : 2 x1  4 x 2  1
x1  2 x 2  1
2 x1  x 2  1
x1 , x 2  0.

UNIT II

4.   A company having plants at A, B and C supplies to the warehouses at D, E, F and
G. Monthly plant capacities are 70, 90 and 115 respectively. Monthly warehouse
requirements are 50, 60, 70 and 95 respectively. Unit shipping costs are as follows
:

Warehouses       D      E    F    G
Plants

A             17     20   14   12

B             15     21   25   14

C             15     14   15   16

Determine the optimal solution that minimizes the shipping costs for the company
and calculate the total cost at each stage. Also give the mathematical formulation
of the problem.

Or

5.   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 during the 8
hour working day. Determine :
(a)   Equipment utilization

(b)   Average system time

(c)   Average idle time.

UNIT III

6.   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.

Or

7.   (a)   Explain the importance of critical path in PERT/CPM.

(b)   The three estimates for the activities of a project are given below :

Activity         a   M      t
1–2          5    6     7
1–3          1    1     7
1–4          2    4     12
2–5      3    6    15
3–5      1    1    1
4–6      2    2    8
5–6      1    4    7

UNIT IV

8.   (a)    Describe the characteristics of a ‘‘Two-person zero-sum game’’.
(b)    Solve the game :

B
B1   B2   B3
A1     0    –2   7
A     A2     2    5    6
A3     3    –3   8

Or

9.   Use dynamic programming to solve the L.P.P. :
Maximize Z  4 x 1  14 x 2

Subject to the constraints :
2 x1  7 x 2  21
2 x1  2 x 2  21
x1 , x 2  0 .

———————
(DME 312)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)
Mechanical Engineering
Paper II — DESIGN OF MACHINE ELEMENTS
Time : Three hours                                                            Maximum : 75 marks

Answer Question No. 1 compulsorily.
(15)
Answer ONE question from each Unit.
(4  15 = 60)

1.   (a)     Explain the significance of machine design.
(b)     Explain :
(i)    Normalising
(ii)   Annealing.
(c)     Explain the various stages in stress-stain diagram.
(d)     Explain Notch Sensitivity.
(e)     Derive an expression for maximum efficiency of a square thread screw.
(f)     Define and derive efficiency of a Riveted joint.
(g)     What are the applications of Cotter joint?

UNIT I
2.   (a)     Explain the general procedure in machine design.
(b)     Explain the different mechanical properties and their significance used in
machine design.
Or
3.   (a)     Explain :
(i)    Thermal stress
(ii)   Hoop stress.
(b)     A shaft of 25 mm diameter is subjected to a torque of 60 N-m a bending
moment                                                                      of
90 N-m and an axial load of 6 kN. Calculate the factor of safety, according to
maximum shear stress theory. Assume yield strength of shaft material as
400 mpa.
UNIT II
4.   (a)     Explain Soderberg method for combination of stresses.
(b)     A circular bar of 500 mm length is supported freely at its two ends it is acted
upon by a central concentrated cyclic load having a minimum value of 20 kN
and maximum value of 50 kN. Determine the diameter of shaft by taking a
factor of safety as 1.5, size effect of 0.85, surface finish factor of 0.9. The
material properties of bar are given by ultimate strength of 650 MPa, yield
strength of 500 MPa and endurance strength of 350 MPa.
Or

A screw jack is to lift a load of 80 kN through a height of 400 mm. The elastic
strength of screw material in tension and compression is 200 MPa and in shear
120 MPa. The material for nut is phosphor-bronze for which the elastic limit may
be taken as 100 MPa in tension, 90 MPa in compression and 80 MPa in shear. The
bearing pressure between the nut and the screw is not to exceed 18 N/mm2. Design
the :

(a)     Screw
(b)   Nut for the screw jack.

UNIT III

5.   A bracket is supported by means of 4 rivets of same size, as shown in figure.
Determine the diameter of the rivet of the maximum shear stress is 140 MPa.

All dimensions are in mm.

Or

6.   A bracket carrying a load of 15 kN is to be welded as shown in figure. Find the size
of weld required if the allowable shear stress is not to exceed 80 MPa.

UNIT IV

7.   Design a Knuckle joint to transmit 150 kN. The design stresses may be taken as
75 MPa in tension, 60 MPa in shear and 150 MPa in compression.

Or
8.   Design a sleeve and cotter joint to resist a tensile load of 60 kN. All parts of the
joint are made of the same materials with the following allowable stresses :
 t  60 MPa ,   70 MPa and  C  125 MPa.

—————————
(DME 313)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper III — MACHINE DYNAMICS
Time : Three hours           Maximum : 75 marks

Answer question No. 1 compulsory.           (15 marks)

Answer ONE question from each Unit. (4  15 = 60)

1.   (a)   What is meant by pitching?

(b)   Write a shortnotes on swaying couple.

(c)   What is meant by isochronous governors?

(d)   What do you mean by gyroscopic torque?

(e)   What is meant by rolling of ships?

(f)   What are the various types of dynamometers?

(g)   Differentiate between primary and secondary balancing.

UNIT I

2.   Derive expressions for velocity and acceleration of piston under dynamic force
analysis.

Or

3.   The following data relate to the connecting rod of a reciprocating engine :
Mass = 50 kg, Distance between bearing centres = 900 mm
Diameter of big end bearing = 100mm
Diameter of small end bearing = 80 mm
Time of oscillation when the connecting rod is suspended from big end = 1.7 s,
small end = 1.85 s.
Determine :
(a)   The radius of gyration k of the rod about an axis through centre of mass
perpendicular to the plane of oscillation.
(b)   The moment of inertia of the rod about the same axis and
(c)   The dynamically equivalent system of the connecting rod comprising two
masses, one at the small end bearing centre.

UNIT II

4.   The following data refer to two cylinder locomotive with cranks at 90;
Reciprocating mass per cylinder = 300 kg; Crank radius = 0.3 m; Driving wheel
diameter = 1.8 m; Distance between cylinder centre lines = 0.65 m; Distance
between the driving wheel central planes = 1.55 m. Determine :

(a)   The fraction of the reciprocating masses to be balanced, if the hammer blow
is not to exceed 46 kN at 96.5 km.p.h;

(b)   The variation interactive effort; and

(c)   The maximum swaying couple.

Or

5.   A four cylinder vertical engine has cranks 150 mm long. The planes of rotation of
the first, second and fourth cranks are 400 mm, 200 mm and 200 mm respectively
from the third crank and their reciprocating masses are 50 kg, 60 kg and 50 kg
respectively. Find the mass of the reciprocating parts for the third cylinder and the
relative angular positions of the cranks in order that the engine may be in
complete primary balance.

UNIT III

6.   Explain prony brake dynamometer and rope brake dynamometer with neat
sketches.

Or

7.   (a)   Explain gyroscopic effect of an air craft.

(b)   A four wheeled trolley car of total mass 2000 kg running on rails of 1.6 m
guage, rounds a curve of 30 m radius at 54 km/hr. The track is banked at 8.
The wheels have an external diameter of 0.7 m and each pair with axle has a
mass of 200 kg. The radius of gyration for each pair is 0.3 m. The height of
centre of gravity of the car above the wheel base is 1 m. Determine, allowing
for centrifugal force and gyroscopic couple actions, the pressure on each rail.

UNIT IV

8.   (a)   Write about effort and power of governors.

(b)   The upper arms of a porter governor has lengths 350 mm and are pivoted on
the axis of rotation. The lower arms has lengths 300 mm and are attached to
the sleeve at a distance of 40 mm from the axis. Each ball has a mass of 4 kg
and mass on the sleeve is 45 kg. Determine the equilibrium speed for a
radius of rotation of 200 mm and find also the effort the power of the
governor for 1 percent speed change.

Or

9.   The following particulars refer to a proell governor with open arms : Length of all
arms                                                                               =
200 mm; distance of pivot of arms from the axis of rotation = 40 mm; Length of
extension of lower arms to which each ball is attached = 100 mm; mass of each ball
= 6 kg and mass of the central load = 150 kg. If the radius of rotation of the balls
is 180 mm when the arms are inclined at an angle of 40 to the axis of rotation,
find the equilibrium speed for the above configuration.

———————
(DME 314)
B.Tech. DEGREE EXAMINATION, DECEMBER 2009.

(Examination at the end of Third Year)

Mechanical Engineering

Paper IV — HYDRAULIC MACHINES
Time : Three hours                                                                Maximum : 75 marks

Answer Question No. 1 is compulsory.

(15)

Answer ONE question from each Unit.
(4  15 = 60)

1.     (a)   Write the equation for the thrust and work done when the force is exerted by
a fluid jet on a stationary flat plate. Explain the terms involved in it.

(b)   What are the various types of draft tubes available? Which are more

efficient? Why?

(c)   Write a short note on relief valve.

(d)   What is meant by cavitation in the case of turbines?

(e)   Define coefficient of discharge and slip.

(f)   What is a Hydraulic accumulator? List the different types of accumulators.

(g)   State Froude’s law.

UNIT I

2.     (a)   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 the vane is half that of jet.

(b)   A jet of water 75 mm diameter having a velocity of 20 m/s, strikes normally a
flat smooth plate. Determine the thrust on the plate.
(i)    if the plate is at rest,
(ii)   if the plate is moving in the same direction as the jet with a velocity of 5
m/s.
(iii) Also find the work done per second on the plate in each case and the
efficiency of the jet when the plate is moving.

Or

3.   A jet of water of 80 mm diameter strikes a curved vane at its center with a velocity
of 20 m/s. The curved vane is moving with a velocity of 8 m/s in the direction of jet.
The jet is deflected through an angle of 165. Assuming the plate to be smooth find
:
(a)   Thrust on the plate in the direction of jet.
(b)   Tower of the jet and
(c)   Efficiency of the jet.

UNIT II

4.   (a)   Show that for maximum efficiency of pelton wheel, the bucket speed must be
equal to half the velocity of the jet.
(b)   Determine the efficiency of a Kaplan turbine developing 3000 kW under a net
5 m. It is provided with a draft tube with its inlet (diameter 3 m) set 1.6 m
above the tail race level. A vacuum gage connected to the draft tube indicates
a reading of 5 m of water. Assume draft tube efficiency as 78%.

Or

5.   (a)   Write a short notes on the performance characteristic curves of a turbine.
(b)   A pipe line 1200 m long supplies water to 3 single jet pelton wheels. The head
above the nozzle is 360 m. The velocity coefficient of the nozzle is 0.98 and
the coefficient of friction for the pipe line is 0.02. The turbine efficiency
based on the head at the nozzle is 0.85. The specific speed of each turbine is
15.3 (in m, kw, rpm, units) and the head lost due to friction in the pipe line is
12 m of water. If the operating speed of the turbine is 560 rpm. Determine :
(i)    the total power developed
(ii)   the diameter of each nozzle
(iii) the diameter of pipe line
(iv)   volume of water used per second.

UNIT III

6.   (a)   What is meant by a reciprocating pump? Give the working, principle and
classification of the reciprocating pump.
(b)   A double acting reciprocating pump has piston diameter 250 mm and piston
rod of diameter 50 mm which is one side only. Length of piston stroke is 350
mm and speed of crank moving the piston is 60 rpm. The suction and
delivery heads are 4.5 m and 18 m respectively. Determine the discharge
capacity of the pump and the power required to operate the pump.
Or
7.   (a)   Derive an expression for the work done by impeller.
(b)   Write a brief note on the centrifugal pump.
(i)    connected in series
(ii)   connected in parallel.

UNIT IV

8.   (a)   Explain the procedure followed in Buckingham’s pi theorem.
(b)   Explain the kinematic similarity between model and prototype.

Or

9.   (a)   Explain in detail Hydraulic intensifier with the help of a neat sketch.
(b)   Explain the working of a hydraulic lift with the help of a neat sketch.

——————
(DME 315)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)
Mechanical Engineering
Paper V — I.C. ENGINES AND GAS TURBINES
Time : Three hours                                            Maximum : 75 marks
Answer Question No. 1 compulsorily.                                                       (15)
Answer ONE question from each Unit.                                               (4  15 = 60)

1.   Explain the following :
(a)   Octane number
(b)   Solid fuels
(c)   Surging
(d)   Difference between centrifugal compressor and Axial flow compressor
(e)   Specific fuel consumption
(f)   Performance curves for I.C. Engines
(g)   Carburetion
(h)   Pre whirl of centrifugal compressor
(i)   Intercooling in Gas turbines
(j)   Combustion reactions for liquid fuels
(k)   Ignition lag
(l)   Indicated thermal efficiency
(m) Pressure Coefficient
(n)   Specific thrust.

UNIT I

2.   (a)   What are the advantages and disadvantages of two stroke cycle engines over
four stroke cycle engines?
(b)   What is air fuel ratio? Explain the requirements of air – fuel ratio for
S.I. Engines.
Or

3.   (a)   Explain Bosch fuel pump with neat sketch.
(b)   Explain the valve timing diagrams for S.I. and C.I. Engines.
UNIT II

4.   (a)   Explain in detail the complete record of heat balance sheet.
(b)   An I.C. Engine uses 6 kg of fuel having calorifie value 44,000 kJ/kg in
one                                                               hour.
The I.P. developed is 18 kw. per minute. The temperature of 4.2 kg of
Exhaust gas with specific heat 1 kJ/kg  k was found to rise through

220 C. Draw the heat balance sheet for the Engine.

Or

5.   (a)   Explain liquid and Gaseous fuels.
(b)   A four stroke gasoline Engine develops a brake power of 410 kw. The
Engine consumes 120 kg of fuel in one hour and the air consumption is
40 kg/min. If the mechanical efficiency is 87% and the Calorifie value
of fuel is 43,000 kJ/kg. Determine
(i)        Air–Fuel ratio
(ii)       Indicated and brake thermal efficiency.

UNIT III

6.   (a)   Explain the importance of octance number and cetane number.
(b)   Explain the working of centrifugal compressor with neat sketch.

Or

7.   (a)   Explain the working of axial – flow compressor with neat sketch.
(b)   A rotary air compressor working between 1 bar and 2.5 bar has
internal and external diameters of impellers as 300 mm and
600 mm respectively. The vane angle at inlet and outlet are 30  and
45                                                     respectively.
If the air enters the impeller at 15 m/s.
Find :
(i) Speed of the impeller in r.p.m.
(ii) Work done by the compressor per kg of air.
UNIT IV
8.   (a)   Derive an expression for overall (thermal) efficiency of a gas turbine.
(b)   A gas turbines unit receives air at 100 kPa and 300 k and compress it
adiabatically to 620 kPa with efficiency of compressor 88%. The fuel
has a heating value of 44180 kJ/kg and the fuel/air ratio is 0.017 kg
fuel/kg air. The turbine efficiency is 90%. Calculate the compressor
work, turbine work and thermal efficiency.
Or
9.   (a)   Briefly explain the principle of jet propulsion.
(b)   Explain the working principle of Rocket propulsion with neat sketch.
—————–––
(DME 316)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper VI — METAL CUTTING AND MACHINE TOOLS
Time : Three hours                                               Maximum : 75 marks

Answer Question No. 1 compulsorily.                 (15)

Answer ONE question from each Unit.
(4  15 = 60)

1.   (a)   What is a carriage?
(b)   Define collect?
(c)   What is meant by milling?
(d)   Chip breakers.
(e)   Set the dividing head to mill 41 teeth on a spur wheel blank using simple
indexing.
(f)   What is the advantage of using cutting fluid in machinius?
(g)   What is meant by tool wear.

UNIT I

2.   (a)   Write about the primary and auxillary motions in machine tools.
(b)   How the lathes one classified? Explain in detail about any one type of lathe?

Or

3.   (a)   Explain about spindle speed mechanism in Belt driven used in lathe.
(b)   Describe briefly about taper turning methods on lathe.

UNIT II

4.   (a)   Describe about the spindle feed mechanism used in Drillius machine.

(b)   Describe about the Quick return mechanism.

Or

5.   (a)   Write the construction details of a shaper with a neat sketch.

(b)   Describe about the Honius and happing operations in grinding machines.

UNIT III
6.   (a)   Discuss briefly about up milling and down milling.
(b)   Explain various types of milling cutters that are used in milling.

Or

7.   (a)   Explain with a neat diagram the working of universal milling machine.
(b)   What are the indexing methods used in milling machines?

UNIT IV

8.   (a)   Define tool life? List out the different tool life criteria’s.
(b)   Discuss machining of how carbon steel with HSS cutting tool, the following
Cutting speed m/min 40 50
Tool life            Min    40 10
Derive the V-T relationship.

Or

9.   (a)   What are the advantages of cutting fluids? What are the required
characteristics of a cutting fluid?
(b)   Write the nomenclature of single point cutting tool with neat diagram.

—————————–
(DME 321)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper I — OPERATIONS MANAGEMENT
Time : Three hours                                             Maximum : 75 marks

All questions carry equal marks.

Answer Question No. 1 compulsorily.
(15)

Answer ONE question from each Unit.
(4  15 = 60)

1.   (a)   Mass production.
(b)   Production function.
(c)   Moving average.
(d)   Aggregate planning.
(e)   Outputs.
(f)   Computer Search Model.
(g)   Safety Stock.
(h)   MRP.

(i)   XYZ analysis.

(j)   Inventory control.

(k)   Control chart.

(l)   Zero defect programme.

(m)   OC curves.

(n)   MTBF.

UNIT I

2.   (a)   What do you understand by production? Explain clearly about Job order
Production and batch production.

Or

(b)   What are forecasting variables? Explain with some examples.

UNIT II
3.   (a)   What are short range plans and long range plans? Explain with examples.

Or

(b)   Describe the process involved in the formation of Master scheduling.

UNIT III

4.   (a)   What is the significance of materials management? Briefly explain the
function of materials management.

Or
(b)   What is meant by Economic Order Quantity? What are the models of EOQ?

UNIT IV

5.   (a)   What is multi sampling? Discuss with examples.

Or
(b)   Define ‘Reliability’. What are the factors affecting reliability.

——————
(DME 322)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.

(Examination at the end of Third Year)

Mechanical Engineering

Paper II — DESIGN OF TRANSMISSION ELEMENTS

Time : Three hours                                                          Maximum : 70 marks

Answer Question No. 1 compulsorily.                                                    (7  2 = 14)

Answer ONE question from each Unit.                                                   (4  14 = 56)

1.   Answer in brief :
(a)   What are the various stresses induced in key material?
(b)   Define :
(i)     Circular pitch
(ii)    Diametral pitch
(iii) Module
(iv)    Pressure angle.
(c)   Derive an expression for face width of helical gears.
(d)   Compare design aspects of solid and hollow shafts.
(e)   Explain the properties of lubricants used in journal bearings.
(f)   What are the advantages and disadvantages of rolling contact bearings over
sliding contact bearings?
(g)   Explain the various materials used for the belts.

UNIT I

2.   (a)   Explain the effect of key ways.
(b)   Design the rectangular key for a shaft of 50 mm diameter. The shearing and
crushing stresses for the key material are 42 MPa and 70 MPa respectively.

Or

3.   A shaft is supported by two bearings placed 1 m apart. A 600 mm diameter pulley
is mounted at a distance of 300 mm to the right of left hand bearing and this
drives a pulley directly below it with the help of belt having maximum tension of
2.25 kV. Another pulley 400 mm diameter is placed 200 mm to the left of right
hand bearing and is driven with the help of electric motor and belt, which is placed
horizontally to the right. The angle of contact for both the pulleys is 180 and
  0.24 . Determine the suitable diameter for a solid shaft, allowing working
stress of 63 MPa in tension and 42 MPa in shear for the shaft material. Assume
that the torque on one pulley is equal to that on the other pulley.

UNIT II

4.   Design a journal bearing for a centrifugal pump for the following data : Load on
the journal = 20 kN, speed of the journal = 900 r.p.m. Type of oil is SAE 10, for
which the absolute viscosity at 55C = 0.017 kg/m-s, ambient temperature of oil =
15.5C, maximum bearing pressure for the pump = 1.5 N/mm2.
Calculate also mass of the lubricating oil required for artificial cooling, if rise of
temperature of oil be limited to 10C. Heat dissipation coefficient = 1232 W/m2/C.

Or

5.   Select a single row deep groove ball bearing with the operating cycle listed below,
which will have a life of 15,000 hours.
Fraction of cycle       Type of load      Radial (N)    Thrust (N)    Speed (r.p.m.)   Service factor
1/10             Heavy shocks          2000          1200            400                3.0
1/10             Light shocks          1500          1000            500                1.5
1/5            Moderate shocks         1000          1500            600                2.0
1/5                No shock            1200          2000            800                1.0

Assume radial and axial load factors to be 1.0 and 1.5 respectively and inner race
rotates.

UNIT III

6.   (a)     Derive an expression for centrifugal tension for belt.
(b)     A belt 100 mm wide and 100 mm thick is transmitting power at 1,000
meters/min. The net driving tension is 1.8 times the tension on the slack
side. If the safe permissible stress on the belt section is 1.6 MPa, Calculate
the maximum power, that can be transmitted at this speed. Assume density
of leather as 1000 kg/m3.

Or

7.   Design a chain drive to actuate a compressor from 15 kW electric motor running at
1000 r.p.m., the compressor speed being 350 r.p.m. The minimum centre distance
is 500 mm. The compressor operates 16 hours per day. The chain tension may be
adjusted by shifting the motor on slides.

UNIT IV

8.   A reciprocating compressor is to be connected to an electric motor with the help of
spur gears. The distance between the shafts is to be 500 mm. The speed of the
electric motor is
9.    900 r.p.m. and the speed of the compressor shaft is to be 200 r.p.m. The torque, to
be transmitted is 5,000 N-m. Taking starting torque as 25% more than the normal
torque. Determine(a) module and face width of the gears using 20 stub teeth (b) number of teeth and p

Or

10.   A pair of bevel gears connect two shafts at right angles and transmits 9 kW.
Determine the required module and gear diameters for the following specifications
:
Particulars              Pinion              Gear
Number of teeth                    21                 60
Material                       Semi-steel       Gray cast iron
Brinell hardness number            200                160
Allowable static stress          85 MPa             55 MPa
Speed                         1,200 r.p.m.        420 r.p.m.
Tooth profile                14 1  composite
2
14 1  composite
2

Check the gears for dynamic and wear loads.

———————
(DME 323)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper III — MECHANICAL VIBRATIONS
Time : Three hours                                              Maximum : 75 marks

Answer Question No. 1 compulsorily.
(15)

Answer ONE question from each Unit.
(4  15 = 60)

1.   (a)   Explain different types of Vibrations.
(b)   Explain Beats Phenomenon.
(c)   Derive an expression for natural frequency of Free Torsional Vibrations.
(d)   Explain Whirling of Shafts.
(e)   What is Eigen Value Problem?
(f)   Explain Critical Ration and Damping Ratio.
(g)   Explain the terms Beating and Transmissibility.

UNIT I
2.   (a)  What is Equivalent Viscous Damping? Is the Equivalent Viscous Damping
factor a constant?
(b) How can we obtain the frequency, phase and amplitude of a harmonic motion
from the corresponding rotating factor?
Or
3.   Determine the natural frequency of a vibrating system as shown in figure.

UNIT II
4.   Calculate the natural frequency of transverse vibration of a shaft 20 mm diameter
and 0.6 m long carrying a mass of 1 kg at its mid-point. The density of the shaft
material is 40 Mg/m3 and Young’s modulus is 200 GN/m2. Assume the shaft to be
freely supported. Also calculate the whirling speed of the shaft.
Or

5.   A mass of 10 kg is suspended from one end of a helical spring, the other end being
fixed. The stiffness of the spring is 10 N/m. The viscous damping causes the
amplitude to decrease to one-tenth of the initial value in four complete oscillations
of a periodic force of 150 cossot N is applied at the mass in the vertical direction,
find the amplitude of the forced vibrations? What is the value of resonance?

UNIT III

6.   (a)   Explain principal modes of Vibration.
(b)   Explain Centrifugal Pendulum Absorber.

Or

7.   (a)   Explain forced vibrations with Coulomb Damping.
(b)   Derive an expressed for undamped forced vibrations with harmonic
excitation.

UNIT IV

8.   (a)   Explain Rayleigh–Ritz method.
(b)   Explain Eigen values and Eigen Vectors in multi-degree of freedom systems

Or

9.   Explain principal of Rayleigh’s method using suitable example for simply
supported beam of uniform cross section. Determine fundamental frequency.

—————————
(DME 324)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper IV — BASIC ELECTRONICS
AND MICROPROCESSORS
Time : Three hours                                                 Maximum : 75 marks
All questions carry equal marks.
Answer Question No. 1 Compulsorily.
(15)
Answer ONE question from each Unit.
(4  15 = 60)
1.   (a)   Why are diodes not operated in the breakdown region in rectifier service?
(b)   Why is capacitor preferred to choke as input filter in a rectifier?
(c)   Define ripple factor and give ideal values for HWR and FWR.
(d)   List few applications of BJT.
(e)   Name different regions of operation of BJI.
(f)   Draw the VI characteristics of a zener diode.

(g)   What are the different biasing techniques of a BJT?

(h)   Draw the circuit OP amp as a summer.

(i)   Represent 0-16 decimal numbers in Hexadecimal.

(j)   Draw the figure of a simple flip-flop.

(k)   List the different addressing modes of 8083.

(l)   Define a static RAM.

(m)   Convert (36)10 to BCD number.

(n)   What are the applications of multiplexer?

UNIT I

2.   (a)   Explain Half-wave rectifier derive expression for ripple factor and voltage
regulation without filters.
(b)   Explain transistor actor. Draw the input and output characteristics of
transistor in common emitter configuration.

Or

3.   (a)   Write the advantages of FET over BJT.

(b)   Explain the working of JFET and explain gm, rd and µ . Derive the relation
between them.
UNIT II

4.   (a)   What is an Oscillator? Discuss the circuit operation of a Colpitts oscillator
with a circuit diagram.

(b)   Explain the action of multivibrator in Astable mode.
Or

5.   (a)   What are the characteristics of an ideal op amp? Draw the circuit of an op
amp as an integrator.

(b)   Discuss the circuit operation of a Hartley oscillator with a neat diagram.
UNIT III

6.   (a)   Convert (4057.06)8 = (X)10 = (X)16.

(b)   What are universal gates? Implement EX-OR gate using any one universal
gate.

Or

7.   (a)   Describe the operations performed by encoder.

(b)   What is meant by toggling? Explain the operation of a JK filp flop with the
help of truth table.

UNIT IV

8.   (a)   Explain the internal architure of 8085.

(b)   Explain the following instructions of 8085 CMPM, RAR, RAL, XCHG and
XTHL.

Or

9.   (a)   Write an ALP of 8085 to fin sum of series of 8-bit numbers.

(b)   Discuss the different addressing modes of 8085.

———————
(DME 325)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper V — HEAT TRANSFER

Time : Three hours                 Maximum : 75 marks

Answer Q. No. 1 compulsorily.
(15)

Answer ONE question from each Unit.
(4  15 = 60)

1.   (a)   Briefly explain the Fourier Law.

(b)   Differentiate between steady and transient heat conduction.

(c)   What is the Nusselt number?

(d)   What is the difference between natural and forced convection heat transfer?

(e)   Sketch and explain the parallel flow heat exchange.

(f)   Briefly explain Kirchoff’s law.

(g)   Define NTU.

UNIT I

2.   (a)   Describe the mechanisms of heat transfer.
(b)   Identify the mode of heat transfer in the following :
(i)    Heat transfer from a room heater
(ii)   Boiling water in a boiler
(iii) Cooling of I.C engine cylinder by air.
(c) A metallic plate, 3 cm thick is maintained at 400C on one side and 100C on
the other. How much heat is transferred through the plate? (K = 370 w/mK)

Or

3.   (a)   Derive the equations for radial test conduction through cylindrical system.
(b) A thick walled copper cylinder has an inside radius of 1 cm and an outside
2 cm. The inner and outer surfaces are held at 310C and 290C respectively.
Assume
K varies with temperature as K (w/mk) = 371.9 [1 – 9.25  10–5(7 – 150)].
Determine the heat loss per unit length.

UNIT II

4.   (a) What is lumped capacity? What are the assumptions for lumped capacity
analyses?
(b) A 40  40 cm copper slab 5 mm thick at a uniform temperature of 250C
suddenly has its surface temperature lowered to 30C. Find the time at which
the slab temperature becomes 90C. R = 9000 kg/m3, C = 0.38 kg/kgk, K = 370
w/mk and h = 90 w/m2 k.

Or

5.   (a)    Explain in detail the Colburn analogy?
(b) Air at 20C is flowing along a heated flat plate at 134C at a velocity of 3 m/s.
The plate is 2 m long and 1.5 m wide. Calculate the thickness of the
hydrodynamic boundary layer and the skin friction coefficient at 40 cm from
the leading edge of the plate. The kinematic viscosity of air at 20C may be
taken at as 15.06  10–6 m2/s.

UNIT III

6.   (a)    Define Nusselt number and what is its significance.
(b) A vertical plate 0.4 m high and 1 m wide maintained at a uniform
temperature 120C is exposed to atmosphere air at 30C. Calculate average
heat transfer coefficient for natural convection and the total heat transfer
from both the surfaces by natural convection in the air.

Or

7.   (a)    What are fouling factors? Explain their effect in heat exchange design.
(b) Determine the overall heat transfer co-efficient U 0 based on the outer surface
of                                                                            a
2.54 cm, O.D. 2.286 cm I.D. heat exchange tube (K = 102 w/mk) if the heat
transfer coefficients at the inside and outside of the tube are h i = 5500 w/m2
k and    h 0  3800    w/m2 k respectively and the fouling factors are
R f 0  R fi  0.0002 m2/wk.

UNIT IV

8.   (a)    Distinguish between :
(i)    A black body and gray body
(ii)   Absorptivity and emissivity of a surface
(iii) Specular and diffuse surfaces.
(b) Estimate the rate of solar radiation on a plane normal to sunrays. Assume the
sun to be a block body at a temperature of 5527C. The diameter of the sun, D
= 1.39  106 km and its distance from the earth l is 1.5  108 km.

Or

9.     (a)   Calculate the shape factor of a cylindrical cavity, shown in Fig. With respect
to itself.

(b)    Explain the concept of black body.

——————
(DME 326)

B.Tech. DEGREE EXAMINATION, DECEMBER 2009.
(Examination at the end of Third Year)

Mechanical Engineering

Paper VI — ENGINEERING METROLOGY
Time : Three hours                                             Maximum : 75 marks

Answer Question No. 1 compulsorily.
(1  15 = 15)
Answer ONE question from each Unit.
(4  15 = 60)

1.   (a)   What is meant by shaft basis system?
(b)   Define tolerance.
(c)   What is the use of spirit level?
(d)   What are limit gauges?
(e)   Define Jig.
(f)   What is the use of auto collimator?
(g)   What is meant by inspection?
(h)   What are the advantages of (MM)?
(i)   Use of plug gauges?
(j)   Applications of limit gauges?
(k)   Define accuracy.
(l)   Use of V-block.
(m)   Various methods of measuring the minor diameter of thread?
(n)   Specification of sine-bar.
(o)   Discuss about interferrometry.

UNIT I

2.   (a)   What are the systems of writing tolerances? Explain in detail about them.
(b)   Discuss briefly the use of limit gauges to control the size of parts on shop
floor.

Or

3.   (a)   In a hole and shaft assembly of 30 mm nominal size, the tolerances for hole
and shaft are specified below
Hole : 30 0..02 mm ; Shaft : 30 0..040 mm
 0 000                 0 070

Determine :
(i) Maximum and minimum clearance obtainable
(ii)   Allowance
(iii) Hole and shaft tolerance
(iv)   Type of fit.
(b)   Explain the principle of GO and NO GO gauge.

UNIT II

4.   (a)   With a neat diagram explain about plate fixture and angle fixture.
(b)   What is the difference between hobbing and milling               process   for
manufacturing of gears? Discuss their fields of applications.

Or

5.   (a)   Explain the process of gear hobbing with a neat sketch and also list out the
(b)   List out the gear finishing methods and explain any one of it.

UNIT III

6.   (a)   Describe the following pitch errors of thread in brief:
(i)    Periodic error
(ii)   Drunken error.
(b)   Describe the following methods of measuring the effective diameter of screw
(ii)   One wire method.

Or

7.   (a)   Measurement of major diameter by using ordinary micrometer and using
bench micrometer.
(b)   Briefly explain the followings :
(i)    Straight edges
(ii)   Angle plates.

UNIT IV

8.   (a)   How the Tomilson surface meter works? What are the advantages compared
to other methods?
(b)   Explain the following :
(i)    Waviness
(ii)   Surface finish
(iii) Roughness.

Or
9.   (a)   Write down the different types of coordinate measuring machines. Explain
any one type in detail and list out the advantages and possible sources of
error in CMM.
(b)   Name the various alignment tests to be performed on hathe, describe any two
of them in detail.

————————

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