MECHANICAL ENGINEERING-II

1.Match List I with List II and select the correct answer

List I ListII
A.Pelton wheel(single jet) 1. medium discharge,low head
2. High discharge,low head
B. Francis Turbine 3. Medium discharge, medium head
C. Kaplan Turbine 4. Low discharge, high head
A B C
4 3 2
1 3 4
4 1 3
I 2 3


2. Reversible adiabatic process may be expressed as equal to

<img src='./qimages/1648-2a.jpg'>

<img src='./qimages/1648-2b.jpg'>

<img src='./qimages/1648-2c.jpg'>

<img src='./qimages/1648-2d.jpg'>


3. A gas is so expanded in a cylinder that its temperature remains constant. The resulting variation of pressure vs.volume is

A parabola

A hyperbola

A straight line through origin

None of these

4. According to first law of thermodynamics

Mass and energy are mutually convertible

Heat and work are mutually convertible

Heat flows from hot substance to cold substance

Carnot engine is most efficient


5. Pick up the incorrect statement for centrifugal pumps

Discharge a diameter

Head alpha (speed)2

Head alpha (diameter)2

Discharge alpha speed


6. If the discharge of a centrifugal pump is throttled then its suction lift

Decreases

First increases and then decreases

Remains unchanged

Increases


7. A cylindrical body of cross-sectional area A height H and the density Ps is immersed to a depth h in a liquid of density and tied to the bottom with a string. The tension in the string is <img src='./qimages/1648-7.jpg'>


pghA

<img src='./qimages/1648-7b.jpg'>

<img src='./qimages/1648-7c.jpg'>

<img src='./qimages/1648-7d.jpg'>


8. A manometer measures the pressure differential between two locations of a pipe carrying water. If the manometric liquid is mercury (specific gravity 13.6) and the manometer showed a level difference of20.cm, then the pressure head difference of water between the two tapings will be


1.26m

2.72m

1.36m

2:52m


9. Flow takes place at Reynolds Number of 1500 in two different pipes with relative
roughness of 0.001 and 0.002. The friction factor


Will be higher for the pipe with relative roughness of 0.001

Will be higher for the pipe having relative roughness of 0.002

Will be the same in both the pipes

In the two pipes cannot be compared on the basis of data given


10. A liquid compressed in cylinder has a volume of O.04m3 at 50kg/cm2 and a volume of
0.039m3 at 150 kg/cm2 The bulk modulus of elasticity of liquid is

400kg/cm2

40x106kg/cm2

40x105kg/cm2

4000kg/cm2


11. A fluid jet is discharging from a 100mm nozzle and the vena contracta formed has a diameter of 90mm. If the coefficient of velocity is 0.95, then the coefficient of discharge for the nozzle is

0.7695

0.81

0.9025

0.855


12. A fully developed laminar viscous flow through a circular tube has the ratio of maximum velocity to average velocity as

3.0

2.0

2.5

1.5

13. If the surface tension of water-air interface is 0.073 the gauge pressure inside a rain drop of 1mm diameter will be

0.146N/m2

73N/m2

146N/m2

292N/m2


14. A stream function is given by The potential function of the flow will be


2xy



-2xy constant

2xy


15. The temperature profile between two metal walls joined together is shown in Fig. From the figure it can be concluded
<img src='./qimages/1648-15.jpg'>


Heat flows from A to B

Heat flows from B to A

Heat is generated at the interface

A is bad conductor of heat


16. According to Fourier's law,amount of heat flow through the body in unit time is equal to

KA dT/dx

KA dT2/dx2

K dx/dT

KA dx/dT


17. Pitch diameter is equal to the product of

Circular pitch and number of teeth

Working depth and number of teeth

Clearance and number of teeth

Module and number of teeth


18. The tension in the cable supporting a lift moving upwards is twice the tension when
the lift moves downwards. What is the acceleration of the lift?


g/4

g/3

g/2

G


19. Whirling speed of a shaft coincides with the natural frequency of its


Transverse vibration

Longitudinal vibration

Torsional vibration

Coupled bending torsional vibration


20. Oscillation of a particle is prescribed by the equation 3cos(0.25pie where t is the time in seconds. The time taken by the particle to move from position of equilibrium to
maximum displacement is


2.0 sec

1.0 sec

0.5 sec

3.0 sec


21. If two objects are weighed in water and both of them lose the same weight, then the
two objects must have identical

Specific gravities

Weights in air

Densities

Volumes


22. 1kg of moist air of RH 70% at 21°C is cooled at constant pressure of 1 bar to 5degC. The vapour pressure at 21°C and 5°C are 0.025 bar and 0.0087 bar. The percentage of water vapour that condenses into water, at 5°C is

66%

85%

51%

17%

23. Two spherical balls of same material and surface finish have their diameters in the ratio of2:1. Both are heated to same temperature and allowed to cool by radiation. Rate of cooling of big ball as compared to smaller one will be in the ratio of

1:2

2:1

1:1

4:1

24. Ninety kilograms of ice at 0deg C are completely melted. Find the entropy change, in kJ/K,if T2=0 degC(Latent heat of fusion is 318.5 kJ/kg.K)

0

45

105

85

25. A solid shaft of 100mm diameter transmits 160 HP at 200rpm.The modulus of rigidity c=8 x105kg/cm2 Then the maximum angle of twist for a length of6 meter is


5°

2.5°

3.2°

2°


26. A perfect gas at 27° C is heated at constant pressure till its volume is double. The final temperature is


54°C

108°C

327°C

600°C


27. The stagnation temperature of an isentropic flow of air is 360 K. If the
temperature is 200 K at a section, then the Mach number of the flow will be

1.0

1.5

3.0

2.0


28. Air at 20°C blows over a plate of 50 cm X 75 cm maintained at 250°C. If the convection heat transfer coefficient is 25W/m20C ,the heat transfer rate is

2.156kW

2156kW

215:6kW

21.56kW


29. A s.mall plastic boat loaded with pieces of steel rods is floating in a bath tub. If the cargo is dumped into the water allowing the boat to float empty, the water level in the tub will

Rise

Remains same

Fall

Cannot be estimated from the information


30. When a jet plane flying at 300m/s is at the very top of its trajectory, the apparent weight of a passenger is one half of her actual weight. Find the radius of curvature R of the flight path at this point. Use 10m/s2 <img src='./qimages/1648-30.jpg'>


22km

18km

30km

16km

31. Two cars are moving in the same direction with a speed of 45km/hr and a distance of 10km separates them. If a car coming from the opposite direction meets these two cars at an interval of 6 minutes, its speed would be

45km/hr

55km/hr

65km/hr

75km/hr

32. If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the later at the same speed will be

Four times the first one

Same as the first one

One and a half times the first one

One fourth of the first one


33. Tungsten in High Speed Steel provides

Hot hardness

Toughness

Wear resistance

Sharp cutting edge


34. Which of the following regions of the electromagnetic spectrum would be used to determine the structure of crystalline solids?

Microwave

Infrared

X-ray

Visible

35. Fluidity in casting operation is greatly influenced by

Melting temperature of molten metal

Pouring temperature of molten metal

Finish of the mould

Carbon content of molten metal

36. Robert Hooke discovered experimentally that within elastic limit

Stress strain

Stress/strain a constant

Stress x strain 1

None of these

37. Two heavy rotating masses are connected by shafts of lengths l1,l2 and l3 and the corresponding diameters are d1, d2 and d3. this system is reduced to a torsionally equivalent length of the shafts is

<img src='./qimages/1648-37.jpg'>


38. Precipitation hardening is applicable for

Pure aluminuim

Low, carbon steel

Non-metal

Aluminium-Copper alloy


39. Match the lists I and II using code given below

A.Car dash board 1.Polyvinylchloride
B.Aircraft windows 2.TEFLON
C.Conduit pipes 3.Polyacrylonitrile
D.Bearings and gears 4.Polymethylmethacrylate

A B C D
1 2 3 4

3 4 1 2

4 3 2 1

2 3 4 1



40. The mass moment of inertia of a cube with edges of length about an axis passing. through an edge.

mb2/2

mb2/6

3mb2/2

2mb2/3


41. A thin cylinder contains fluid at a pressure of 30kg/cm2.The inside diameter of the shell is 60cm and the tensile stress in the material is to be limited to 900kg/cm2 The shell must have minimum wall thickness of

1mm

2.7mm

10mm

9mm

42. When a shaft is subjected to combined twisting moment (T)and bending moment the equivalent twisting moment is equal to

<img src='./qimages/1648-42.jpg'>


43. Two blocks with masses M and m are in contact with each other and are resting on a horizontal frictionless floor. When horizontal force F is applied to the heavier, the blocks accelerate to the right. The force between the two blocks are <img src='./qimages/1648-43.jpg'>



mF/m

mF/M




44. A machine mounted on a single coil spring has a period of vibration of T. If the spring is cut into four equal parts and placed in parallel and the machine is mounted on them, then the period of free vibration of the new system will be


16T

T/4

4T

T/16


45. Dislocations in materials are

Point defect

Surface defect

Planer defect

Line defect

46. Which of the following thermocouple is capable of measuring highest temperature?

Chromel-alumel

Platinum-rhodium

Iridium-rhodium

Iron-constantan

47. A circular rod of 100mm diameter and 500mm length is subjected to a tensile force of 1000kN. Determine the modulus of rigidity if E=2xl05N/mm2 and Poisson's=0.3


0.335xl05 N/mm2

0.521x105 N/mm2

0.7692xl05 N/mm2

0.2256x105 N/mm20

48. For the state of stress shown in the above figure, normal stress .acting on the plane of maximum shear is <img src='./qimages/1648-48.jpg'>


25 MPa tension

75 MPa compression

25 MPa compression

75 MPa tension

49. The effective diameter of an external or internal screw thread, is known as

Minor diameter

Major diameter

Pitch diameter

None of these


50. Consider the following statements: If at section away from the ends of the beam, M represents the bending moment, V the shear force, w the intensity of loading and y represents the deflection of the beam at the section,then 1. dM/dx=V 2. dV/dx=w 3. dw/dx=y Of these statements

1 and 2 are correct

1and 3 are Correct

2 and 3 are correct

1,2 and 3 are correct

51. For a column of length L is fixed at both ends, corresponding Euler's critical load is

<img src='./qimages/1648-51.jpg'>


52. Which one of the following figures is the correct sketch of Mohr's circle of the given state of stress <img src='./qimages/1648-52.jpg'>

<img src='./qimages/1648-52a.jpg'>

<img src='./qimages/1648-52b.jpg'>

<img src='./qimages/1648-52c.jpg'>

<img src='./qimages/1648-52d.jpg'>


53. With a punch for which the maximum crushing stress is 4 times the maximum shearing stress of the plate, the biggest hole that can be punched in the plate would be of diameter equal to

1/4 x Thickness of plate

1/2 x Thickness of plate

Plate thickness

2 x Plate thickness

54. A simply supported beam with width and depth carries a central load Wand undergoes deflection delta at the centre. If the width and depth are interchanged, the Deflection at the centre of the beam would attain the value:

<img src='./qimages/1648-54.jpg'>

55. The given figure shows a cantilever of span subjected to a concentrated load and a moment at the free end. Deflection at the free end is given by <img src='./qimages/1648-55.jpg'>


<img src='./qimages/1648-55a.jpg'>

<img src='./qimages/1648-55b.jpg'>

<img src='./qimages/1648-55c.jpg'>

<img src='./qimages/1648-55d.jpg'>


56. In arc welding, penetration is minimum for

DCSP

DCRP

AC

DCEN

57. Match list-I (welding effects) with list-II (causes) and select the correct answer using the codes given below the lists:

List-I (Welding defects) List-II (Causes)

A. Spatter 1. Damp electrodes
B. Distortion 2. Arc blow
C. Slag inclusion 3. Improper cleaning in multipass Welding
D. Porosity 4. Poor joint selection

A B C D

2 4 3 1
4 2 1 3
2 4 1 3
4 2 3 1


58. Two beams of equal cross cross sectional area subjected to equal bending moment.If one beam has square section and the other has circular section then,

Both the beams will be equally strong

Square section beam will be stronger

Circular section beam will be stronger

Depends on loading condition

59. The number of degree of freedom of a five link plane mechanism with five revolute pairs as Shown in the figure is <img src='./qimages/1648-59.jpg'>

3

4

1

2

60. To ensure self locking in a screw jack,it is essential that helix angle is

Larger than friction angle

None of these

Equal to friction angle

Smaller than friction angle

61. A cutting tool having tool signature as 10, 8,2 will have side rake angle


a)10°







62. In radiographic test, type of defect not detectable by X-Ray is

Delamination in cladded sheet

Porosity in castings

Tungsten inclusion in TIG weld

Undercut in metal arc welding

63. In CAM, "Part programming" refers to

Generation of cutter location data

On-line Inspection

Machine Selection

Tool Selection

64. A 50mm diameter steel rod was turned at 284rpm and tool failure occurred in 10 minutes. The speed was changed to 232rpm and the tool failed in 60 minutes. Assuming straight line relationship between cutting speed and tool life,.the value of Taylorian Exponent is

0.21

0.13

0.11

0.23


65. Which of the following screw thread is adapted for power transmission in one direction

Acme threads

Buttress threads

Square threads

Multiple threads


66. CLA value and RMS values are used for measurement of


Metal hardness

Sharpness of tool edge

Surface dimensions

Surface roughness


67. A sine bar is specified by


Its total length

The size of the rollers

The centre distance between the two rollers

The distance between rollers and upper surface


68. A shaft and hole pair is designated as 50H7d8. This assembly constitutes

Interference fit

Transition fit

Clearance fit

None of the above

69. A milling machine has the following two index plates supplied along with the indexing head:- Plate 15,16,17,18,19,20, hole circles Plate 21,23,27,29,31,33, hole circles
It is proposed to mill a spur gear of 28 teeth using simple indexing method. Which one of the following combinations of index plate and number of revolutions is correct?


Plate 1 revolution and 9 holes in 18 hole circles

Plate 1 revolution and 9 holes in 21 hole circles

Plate 1 revolution and 9 holes in 33 hole circles

Plate 1 revolution and 9 holes in 15 hole circles

70. The initial blank diameter required to form a cylindrical cup of outside diameter and total height having a corner radius is obtained using the formula

<img src='./qimages/1648-70.jpg'>

71. The equation of the tangent to the curve at the point where it cuts the x-axis is




x+20y=7

x-20y=7




72. If the imaginary part of 2z+1/iz+1 is then the locus of the point z in the complex plane










73. General solution of the differential equation is


<img src='./qimages/1648-73a.jpg'>

<img src='./qimages/1648-73b.jpg'>

<img src='./qimages/1648-73c.jpg'>

<img src='./qimages/1648-73d.jpg'>


74. In a simple micrometer with screw pitch 0.5mm and divisions on thimble 50, the reading corresponding to 5 divisions on barrel and 12 divisions on thimble is


2.620mm

2.512mm

5.120mm

5.012mm


75. The value of <img src='./qimages/1648-75.jpg'>

0





1


76. <img src='./qimages/1648-76.jpg'>






0

1

77. The image of the point(1,2,3) in the plane 2x+y+z =13 is









78. The value of curl of the vector <img src='./qimages/1648-78.jpg'> at the point is


2i +3j +14k

2i -3j +14k

2i +3j -14k

2i -3j -14k

79. An open tank contains water to a depth of 2m and oil over it to a depth of 1m. lUhe specific gravity of oil is 0.8, then the pressure intensity at the interface of the two fluid layers will be

9750 N/m2

8720 N/m2

9347 N/m2

7848 N/m2

80. A box contains 6 black and 5 red balls. Two balls are drawn one after another from the box without replacement. The probability for both balls to be red is

3/11

2/11

5/11

25/11