Quiznetik

Design of Machine Elements | Set 2

1. The gears on camshaft and crankshaft are known as

Correct : C. timing gears

2. The material known as high carbon high copper chrome silicon cast steel is used for making

Correct : A. camshaft

3. Camshaft gear is made from which material

Correct : C. bakelite

4. The main reasons for crankshaft wear are

Correct : D. all of the mentioned

5. The main causes of crankshaft vibration are

Correct : D. all of the mentioned

6. In the cam, the distance between the base circle and the nose is called

Correct : A. lift

7. The crankshaft rotates the camshaft using

Correct : B. chain drive

8. The crankshaft should be inspected for

Correct : D. all of the mentioned

9. A radial bearing supports the load that acts along the axis of the shaft.

Correct : B. false

10. Sliding contact bearings, also called plain bearings have no problem of wear.

Correct : B. false

11. Which of the following are true about plasticity?

Correct : D. all of the mentioned

12. Modulus of resilience is defined as

Correct : A. strain energy per unit volume

13. In gear boxes and small size motors, rolling contact bearings are used.

Correct : A. true

14. There is problem of alignment in deep groove ball bearings.

Correct : A. yes

15. Deep groove ball bearing has immense rigidity.

Correct : B. no it has point contact and hence low rigidity

16. Cylindrical load bearing has lower load capacity as compared to deep groove ball bearing.

Correct : B. false

17. Angular contact bearing can take thrust as well as radial loads.

Correct : A. true

18. The angular play bearing must be mounted without axial play.

Correct : A. yes

19. Taper rolling supports

Correct : C. both axial and thrust loads

20. Which of the following cannot tolerate misalignment?

Correct : D. all of the listed

21. Cylinder roller creates lesser noise than deep groove ball bearing.

Correct : B. false

22. Straight bevel gears are easy to design and manufacture and give reasonably good service with quieter operation.

Correct : B. no, noise problem

23. Which of the following creates smoother motion?

Correct : B. spiral bevel gears

24. When the pitch angle is greater than 90⁰, it is called external bevel gear.

Correct : B. internal

25. If pitch angle is >90, the bevel gear is?

Correct : A. internal

26. Crown gears having a pitch angle of 90⁰

Correct : C. >90

27. Which of the following are characteristics of skew bevel gears?

Correct : A. straight teeth

28. Hypoid gears are based on surfaces that are paraboloids of revolution.

Correct : B. false

29. When two hyperboloids are rotated, the resulting motion is

Correct : C. combination of turning and sliding

30. Zerol gears are straight bevel gears with zero spiral angle.

Correct : B. false

31. Zerol gears give lesser contact ratio.

Correct : B. no, larger contact ratio

32. Hydrodynamic lubrication takes place in region?

Correct : B. cd

33. Coefficient of friction is minimum at

Correct : C. c

34. Bearing modulus is the bearing characteristic number at

Correct : B. c

35. If viscosity of the lubricant is very low than BCN will lie in the region

Correct : A. bc

36. The fundamental equation for viscous flow is given by ∆pbhᵌ/6µl where symbols have their usual meanings.

Correct : B. 6 is to be replaced by 12

37. A single transverse weld is preferred over

Correct : B. false

38. Transverse fillet weld can be designed using the same equations as of parallel fillet weld.

Correct : B. false

39. Which of the following are functions of bearings?

Correct : D. all of the listed

40. Which of the following is measure of stiffness?

Correct : A. modulus of elasticity

41. Which of the following facts are true for resilience?

Correct : A. ability of material to absorb energy when deformed elastically

42. Shot blasting process improves the endurance limit of the component.

Correct : A. true

43. While designing a forging, the profile is selected such that the fibrous lines are parallel to the tensile forces and perpendicular to shear forces.

Correct : A. true

44. What is the expression of the bending equation?

Correct : A. m/i = σ/y = e/r

45. The bending stress is

Correct : A. directly proportional to the distance of layer from the neutral layer

46. The critical value at which crack extension occurs is called

Correct : C. fracture toughness

47. If for a curved beam of trapezoidal cross section, radius of neutral axis is 89.1816mm and radius of centroidal axis is 100mm, then find the bending stress at inner fibre whose radius is 50mm. Area of cross section of beam is 7200mm² and the beam is loaded with 100kN of load.

Correct : C. 100.6

48. Which of the following can be the factor of safety for a dead load?

Correct : C. 4

49. For which of the following design factor of safety the design will work properly?

Correct : C. 2

50. While designing shaft on the basis of torsional rigidity, angle of twist is given by?

Correct : B. 584ml/gd⁴

51. If allowable shear stress in the shaft is 70N/mm² and torsional and bending moments are M=1185000N-mm and m=330000N-mm, find the diameter of the shaft.

Correct : C. 44.7mm

52. Calculate the shaft diameter on rigidity basis if torsional moment is 196000N-mm, length of shaft is 1000mm. Permissible angle of twist per meter is 0.5’ and take G=79300N/mm².

Correct : B. 41.2mm

53. The stiffness of solid shaft is more than the stiffness of hollow shaft with same weight.

Correct : B. false

54. Solid shaft is costlier than hollow shaft of same weight.

Correct : B. false

55. Flexible shafts have        rigidity in torsion making them flexible.

Correct : B. high

56. Flexible shafts have              rigidity in bending moment.

Correct : B. low

57. A force 2P is acting on the double transverse fillet weld. Leg of weld is h and length l. Determine the shear stress in a plane inclined at θ with horizontal.

Correct : A. psinθ(sinθ+cosθ)/hl

58. Maximum shear stress in transverse fillet weld of leg h and length l is

Correct : B. 1.21p/hl

59. Hollow saddle key is superior to flat saddle key as far as power transmitting capability is concerned.

Correct : B. false

60. Saddle key is more suitable than sunk key for heavy duty applications.

Correct : B. false

61. The main advantage of sunk key is that it is a            drive.

Correct : A. positive

62. Woodruff key permits            movement b/w shaft and the hub.

Correct : B. radial

63. Determine the length of kennedy key required to transmit 1200N-m and allowable shear in the key is 40N/mm². The diameter of shaft and width of key can be taken as 40mm and 10mm respectively.

Correct : D. 53mm

64. Splines are keys.

Correct : A. true

65. Refer to fig. Two plates are fastened by means of two bolts. The yield strength of bolt is 400N/mm² and factor of safety is 4. Determine the permissible shear stress in the bolts.

Correct : B. 50n/mm²

66. Determine the secondary shear stress acting on the bolt 3 and its direction. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm.Also P=5kN acts at a distance of 200mm from the channel.

Correct : C. 6100n vertically up

67. Determine the size of the bolts if yield strength of bolt is 400N/mm² and factor of safety is 4. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm. Also P=5kN acts at a distance of 200mm from the channel.

Correct : B. 13.44mm

68. Knuckle Joint can’t be used to connect two intersecting rods.

Correct : B. no, it can’t be used

69. A knuckle joint is also called socket pin joint.

Correct : B. false

70. If knuckle joint is to fail by crushing failure of pin in fork, then determine the diameter of knuckle pin when 50kN axial tensile force act on rods. Given: Max allowable compressive stress=25N/mm², thickness of each eye of fork=25mm.

Correct : A. 40mm

71. Can the cotter joint be used to connect slide spindle and fork of valve mechanism?

Correct : A. true

72. Among gas and electric arc welding, which has the higher rate of heating?

Correct : B. electric arc welding

73. Forge welding involves heating of parts to elastic stage and joint is prepared by impact force.

Correct : B. no, it is done up to plastic stage

74. Which of the following isn’t a main part of rivet?

Correct : D. thread

75. In hot riveting the shank portion is subjected to compressive stress.

Correct : B. false

76. Among punching and drilling, punching is safer.

Correct : B. false

77. What is the amount of sea coal needed in cast irons for small casting moulding sands?

Correct : A. 1%

78. The longest leaf in a leaf spring is called centre leaf.

Correct : B. it is called master leaf

79. If the spring is compressed completely and the adjacent coils touch each other,the the length of spring is called as?

Correct : A. solid length

80. If uncompressed length of spring is 40mm and number of coils 10mm, then pitch of coil is?

Correct : B. 40/9

81. Active and inactive, both types of coils support the load although both don’t participate in spring action.

Correct : B. inactive coils don’t support the load

82. The coefficient of fluctuation of speed is the                    of maximum fluctuation of speed and the mean speed.

Correct : B. ratio

83. If E = Mean kinetic energy of the flywheel, CS = Coefficient of fluctuation of speed and Δ E = Maximum fluctuation of energy, then

Correct : B. Δe = e2 × cs

84. The tensile stress in the flywheel rim due to the centrifugal force acting on the rim is given by

Correct : D. ρ v2

85. In a four stroke cycle engine camshaft revolves at              the crank speed.

Correct : B. half

86. Crankshafts are usually constructed by

Correct : B. drop forging

87. A               bearing supports the load acting along the axis of the shaft.

Correct : A. thrust

88. In steam and gas turbines, rolling contact bearings are used.

Correct : B. false

89. Deep groove ball bearings creates a lot of noise.

Correct : B. they create very less noise

90. In angular contact bearings,          bearings are required to take thrust load in both directions.

Correct : C. 2

91. Which of the following isn’t the property of taper roller?

Correct : C. take low radial and heavy loads

92. Which of the following cannot take radial load?

Correct : C. thrust ball bearing

93. There are          common types of bevel gears.

Correct : B. 2

94. Miter gears are the bevel gears mounted on shaft which are intersecting at angle greater than 90.

Correct : B. false

95. In hypoid bevel gears, shafts may continue past each other.

Correct : A. true

96. Hypoid gears have the following characteristics.

Correct : D. all of the mentioned

97. The bearing characteristic number shown in the graph is directly proportional to the unit bearing pressure.

Correct : B. false

98. A single transverse weld is preferred over double transverse fillet weld.

Correct : B. false

99. 5 SELECTION OF ROLLING CONTACT BEARINGS

Correct : A. thrust