Quiznetik

Machine Design | Set 2

1. If two gears having 24 and 96 teeth mesh each other, they must have been cut

Correct : C. With cutters of same moduic

2. The following type of mechanism is not possible in any framed structure as an independent mechanism

Correct : A. Joint mechanism

3. A solid shaft and a hollow shaft are to be of equal strength in torsion. The hollow shaft is to be 10% larger in diameter than the solid shaft. The ratio of the weight of the hollow shaft will be (both shafts being made of same material)

Correct : C. 2

4. The maximum size of the fillet weld that can be used is

Correct : B. 3 mm

5. Spring driven watches and clocks utilise

Correct : D. Cycloid gears

6. The shape or form factor is introduced in the design of compression members to represent the effect of

Correct : C. local buckling

7. The plastic design of steel structures which is based on upper bound theorem is

Correct : E. unsafe, safe

8. Poisson's ratio for rubber is taken as

Correct : E. 0.5

9. In above problem the cone pitch angle of the pinion will be

Correct : D. sin-1 0.5

10. Cycloidal profile gears are used in

Correct : D. Watches and clocks

11. The ratio of lateral strain to linear strain is

Correct : D. Poisson ratio

12. In case of worm and worm wheel drives, the axes of the two are

Correct : D. non-parallel and non-intersecting

13. A close coiled helical spring is compressed. Its wire is subjected to

Correct : C. Tension

14. The plastic design of a structure based on which of the following is always safe?

Correct : B. Statistical method of plastic analysis

15. In the case of ball bearings the contacting areas between balls and running tracks are

Correct : C. elliptical

16. The notch angle of Izod impact test specimen is

Correct : C. 45?

17. Scraping of lathe bed helps in

Correct : A. lubrication

18. In an inverted tooth chain the included angle between the outer faces of the teeth?

Correct : C. 60 to 75

19. The value of yield stress for structural steel is about

Correct : E. 2600 kg/cm2

20. A warm gear is generally made of

Correct : C. Cast iron

21. The diameter of rivets for 20 mm thick plates would be

Correct : D. 40 mm

22. The ratio of the plastic moment capacity to the yield moment capacity of a rolled steel beam section is about

Correct : C. 1.15

23. Which pair of gears usually has high friction losses?

Correct : E. Worm and worm wheel

24. In plastic analysis, the shape factor of a triangular section is

Correct : C. 2.34

25. In case of quadruple riveted butt joints the joint efficiency is usually assumed in the range

Correct : C. 85-95%

26. A V-belt having B section is generally used when the power to be transmitted is in the range

Correct : E. 3-25 HP

27. In which of the following gears the lowest degree of accuracy can be expected

Correct : C. Farm machinery

28. Induction motors are generally provided with

Correct : C. Ball or roller bearings

29. Which of the following gears are free from axial thrust?

Correct : E. Herringbone gears

30. The phenomenon of eloggation and contraction of the belt is known as

Correct : B. Creep

31. Rankine theory is applied to

Correct : A. bruite materials

32. The clamping nut of the turn buckle has

Correct : C. Right hand threads on one side and left hand threads on the other side

33. Helical springs are not subjected to

Correct : D. Hoop stress

34. The uniform rate of descent is maintained by a brake on the drum which applies the necessary torque of 300 kg-m what additional brake torque is required to bring the system to rest in 0.50 second?

Correct : C. 2054 N-m

35. The part of the tooth which lies between the pitch and dedendum circle is known as

Correct : E. Flank

36. Total strain energy theory for the failure of a material at elastic limit is also known as

Correct : B. Von mises theory

37. A solid shaft of 100 mm diameter transmits 100 HP at (450/?) r.p.m. The torque in kg-m on the shaft would be

Correct : C. 500

38. Stone crusher rolls are generally made of

Correct : E. High carbon steel

39. The 'crowning' of flat pulleys is generally done

Correct : C. To prevent the belt from running off the pulley

40. Piston rings are usually made of

Correct : B. Cast iron

41. The main difference between rigid and flexible coupling for shafts transmitting power is

Correct : B. a flexible element is inserted around coupling bolts in one of the flanges

42. Teflon is used for bearings

Correct : A. When low coefficient of friction is desired

43. In case of a Saddle key

Correct : C. The key ways is cut in hub only

44. For determination of allowable stress in axial compression, IS : 800-1962 has adopted

Correct : B. Secant formula

45. Braking system on earth moving machinery is

Correct : C. Hydraulic braking

46. In a butt welded joint, the size of weld is

Correct : A. 0.5 times the throat of weld

47. The shape factor of an isosceles triangle for bending about the axis parallel to the base is

Correct : C. 2.34

48. A pivoted segment type thrust bearing is used in order to provide

Correct : B. A converging film of oil

49. The pitch of threads on a lock-nut is

Correct : D. Same as that of nut

50. Aircraft body is

Correct : B. Riveted structure

51. The weakest plane in a fillet weld is

Correct : A. the throat

52. The holes in plates for reveting are usually made by

Correct : D. Drilling

53. Which of the following treatment is often recommended for parts operating under corrosive conditions?

Correct : B. tempering

54. A material is generally classified as brittle if the percentage elongation (in a gauge length of 50 mm) is less than

Correct : D. 5%

55. A flange coupling is

Correct : B. Used for collinear shafts

56. Splines are used when

Correct : A. Axial relative motion between shaft and hub is necessary

57. Bolts in structures are often tightened upto or beyond the yield point because

Correct : C. it improves endurance strength

58. A triple threaded worm has a pitch diameter of 100 mm and an axial pitch of 22 mm. The lead angle will be

Correct : A. tan-1 0.21

59. Spigot and socket joints are used on pipes

Correct : A. Which are buried underground

60. In a compression test the fracture in cast iron specimen would occur along

Correct : A. An oblique plane

61. If the allowable shear stress is 960 kg/sq. cm for the size h cm, the allowable force per cm of weld length would be

Correct : A. 670 h

62. In case of a knuckle joint the pin is likely to fail in

Correct : C. Double shear

63. Shot peening leaves the material surface in

Correct : C. residual compressive stress

64. A Babbit is

Correct : E. Antimony bearing lead or tin alloy

65. Low pressure angle on gears results in

Correct : A. Weaker teeth

66. An eye bolt is generally provided on

Correct : C. Electric motors

67. The satisfactory method of reclaiming worn out and under sized part subject to fatigue loads is

Correct : C. Electroplating

68. The usual clearance provided in hydrodynamic bearing per mm of diameter of shaft is

Correct : A. 1 micron

69. Dead weight type safety valve is not used on locomotives because

Correct : B. It is susceptible to vibratory forces

70. Extrafine threaded connections are generally recommended for

Correct : D. thin walled assemblies

71. A square key is

Correct : A. Equally strong in shear and compression

72. A steel specified as St 50 will have a tensile strength of approximately

Correct : B. 50 kg/mm2

73. The chain used in motor cycles is generally

Correct : B. Silent type

74. In gear design, addendum is equal to

Correct : D. Module

75. Lubricant is not required in

Correct : B. Electromagnetic bearing

76. A connecting rod in an IC Engine is to be designed against buckling. The end conditions considered are

Correct : C. Both the ends are hinged

77. A ball bearing cannot be provided for

Correct : A. Big ends of connecting rods for I.C. engines

78. Which of the following drive has accurate speed ratio?

Correct : B. Timing belt drive

79. Under which condition a material ordinatily said to be ductile undergoes a fracture similar to that of a brittle material

Correct : D. All of the above

80. When minimum axial thrust is the criteria, the choice of gears would been

Correct : C. Herringbone gears

81. A compressed air cylinder carries approximately 70 kg/cm2 pressure at the time of delivery. The inside diameter is 25 cm. If the steel has a yield point of 2300 kg/sq cm and a safety factor of 2.5 the wall thickness should be

Correct : A. 10 mm

82. If during operation a boiler bursts, the matter should be reported to

Correct : D. Boiler inspector

83. The compression members tend to buckle in the direction of

Correct : D. Least radius of gyration

84. A concrete wall generally

Correct : B. Reflects sound

85. When the bolt is subjected to shock loading the resilience of the bolt should be considered in order to prevent breakege at

Correct : C. Threaded portion

86. Maximum efficiency expected in case of single mech supr gears is around

Correct : B. 98%

87. In a gas turbine rotor a radial stress of 300 kg/sq cm tensile and 500 kg/sq cm tangential stress have been found at a point. The maximum shear stress at this point would be

Correct : B. 250 kg/cm2

88. The life of ball bearings as listed in catalogue represents

Correct : B. 90% survival rate

89. Rinkine-Gordon formula for buckling load is adopted for columns having slenderness ratio between

Correct : D. 120 and 200

90. Jaw clutches

Correct : A. cause shock loads when engaging

91. A rack is a gear

Correct : D. With infinite number of teeth

92. Expansion joints are provided on pipes carrying

Correct : D. Steam

93. The advantage of needle roller bearing over ball bearing is

Correct : D. Large ratio of load capacity to size

94. A V-belt designated as C 120 will have

Correct : C. 120 inch as the length of belt

95. Dielectric strength of a material is

Correct : A. Capacity to withstand high voltage

96. According to IS 800, the lacing bars should resist a transverse shear equal to

Correct : B. 2.50%

97. The bunkers are the containers in which the plan of rupture intersects

Correct : E. the top surface of material stored

98. Laser treatment of components increases fatigue resistance of metals by

Correct : C. freezing discontinuities

99. Failure of rolling bearings occurs mainly due to

Correct : B. fatigue

100. In elevated circular steel tanks, conical bottoms are attached when

Correct : E. water is muddy