Elements of Machine Design-02

  1. Fundamentals of design
  2. Design of joints, levers and offset links
  3. Design of shafts, keys and couplings
  4. Design of power screws
  5. Design of springs
  6. Design of bolted and welded joints
  7. Selection of anti-friction bearings and gears

Fundamentals of machine design

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1   During a tensile loading, the length of a steel rod is changed by 2 mm. If the original length of the rod has been 20 mm, what is the amount of strain induced
    (A)   0.1
    (B)   2
    (C)   0.9
    (D)   0.22

2   Stress on components is expressed in ….
    (A)   N/mm²
    (B)   kN/m²
    (C)   Pascal
    (D)   All of the above

3   Shear forces are —— forces.
    (A)   Aligned.
    (B)   Unaligned
    (C)   Perpendicular
    (D)   Parallel

4   The components having length in —— are usually Buckle.
    (A)   X- direction
    (B)   Y direction
    (C)   Z- direction
    (D)   X-Y direction

5   Flexure is also known as —–
    (A)   Distortion
    (B)   Failure
    (C)   Bending
    (D)   Twisting

6   Cyclic loads below significant load causes
    (A)   Bending
    (B)   Fatigue
    (C)   Wrapping
    (D)   Compression

7   Tensile stresses are applied —– to applied tensile force
    (A)   Parallel
    (B)   Perpendicular
    (C)   cross-sectional
    (D)   In same direction

8   Compressive forces are
    (A)   Towards the point
    (B)   Opposite to point
    (C)   Both
    (D)   Can’t say

9   Strength of material is maximum in
    (A)   Tension
    (B)   Compression
    (C)   Twisting
    (D)   Any of above

10   Stressed parts are always kept in tension.
    (A)   TRUE
    (B)   FALSE

11   While designing a forging, the profile is selected such that the fibrous lines are parallel to the tensile forces and perpendicular to shear forces.
    (A)   TRUE
    (B)   FALSE

12   Which of the following is not a reason to design and redesign a product?
    (A)   Optimum design
    (B)   Innovation
    (C)   Appearance
    (D)   None of the above

13   In design process, which process is followed after selecting the material?
    (A)   Selecting factor of safety
    (B)   Synthesis
    (C)   Analysis of forces
    (D)   Determining mode of failure

14   Which of the following is not a reason to design and redesign a product?
    (A)   Optimum design
    (B)   Innovation
    (C)   Appearance
    (D)   None of these

15   The following standard(s) is (are) used in Mechanical engineering design.
    (A)   Standards for materials
    (B)   Standard for testing of products
    (C)   Standards for Fits, Tolerances and surface finish of component
    (D)   All of the above

16   The following design process is also known as ‘over the wall’ process
    (A)   Sequential Design process
    (B)   Concurrent Engineering
    (C)   Both A and B
    (D)   None of the above

17   The elongation of a bar is 0.5 mm, when a tensile stress of 200 N/mm2 acts on it. Determine original length of a bar if modulus of elasticity is 150 x 103.
    (A)   375.93 mm
    (B)   300 mm
    (C)   360 mm
    (D)   None of the above

18   Deformation per unit length is called as ________
    (A)   strain
    (B)   stress
    (C)   modulus of elasticity
    (D)   none of the above

19   In design process, which process is followed after selecting the material?
    (A)   Selecting factor of safety
    (B)   Synthesis
    (C)   Analysis of forces
    (D)   Determining mode of failure.

20   Which of the following materials do not have a well-defined yield point?
    (A)   Heat treated steel
    (B)   Concrete
    (C)   Carbon fiber
    (D)   All of the above

21   In stress-strain diagram, up to proportional limit ______
    (A)   stress is inversely proportional to strain
    (B)   force is directly proportional to displacement
    (C)   stress is directly proportional to strain
    (D)   strain is directly proportional to stress

22   Factor of safety is the ratio of _________
    (A)   working stress and ultimate strength
    (B)   yield strength and endurance strength
    (C)   ultimate strength and yield strength
    (D)   yield strength and working stress

23   The ratio of endurance strength and allowable stress is used to determine FOS for _____
    (A)   fatigue loading
    (B)   static loading of brittle materials
    (C)   static loading of ductile materials
    (D)   all of the above

24   Which of the following is the numerator of factor safety formula?
    (A)   Working stress
    (B)   Shear stress
    (C)   Tensile stress
    (D)   Ultimate Stress

25   Which of the following can be the factor of safety for a dead load?
    (A)   6
    (B)   2
    (C)   4
    (D)   7

26   Which of the following can be the factor of safety for shock loading?
    (A)   11
    (B)   13
    (C)   4
    (D)   7

27   Factor of safety is used to find out the reliability of the design.
    (A)   TRUE
    (B)   FALSE

28   What can understand by the factor of safety equal to one?
    (A)   It means that the structure will fail under load
    (B)   It means that the structure will only support the actual load
    (C)   it means that the structure will support more than the actual load
    (D)   There is no relation between factor safety and load application

29   For which of the following design factor of safety the design will work properly?
    (A)   0.1
    (B)   1
    (C)   2
    (D)   0.9

30   What is a safe factor of failure for a component which on failure can result in financial loss or serious injury?
    (A)   1
    (B)   2
    (C)   3
    (D)   4

31   Design factor for most aircraft structures is 2.
    (A)   TRUE
    (B)   FALSE

32   What is the factor of safety under suddenly applied load?
    (A)   2 and 4
    (B)   4 and 8
    (C)   8 and 16
    (D)   None

33   Safety factor in case of a ductile material is
    (A)   Real stress/unit stress
    (B)   Ultimate stress/maximum stress
    (C)   Yield stress/ allowable stress
    (D)   None

34   Effect of higher factor of safety on cost of the material?
    (A)   Increases
    (B)   Decreases
    (C)   No change
    (D)   None

35   The factor of safety for a ductile material
    (A)   σyp/σallow
    (B)   (b)σult/σallow
    (C)   σult/σyp

36   Factor of safety is the ratio of —–
    (A)   allowable stress to critical stress
    (B)   critical stress to allowable stress
    (C)   normal stress to shear stress
    (D)   shear stress to normal stress

37   The factor of safety for—–
    (A)   steel and concrete are same
    (B)   steel is lower than that for concrete
    (C)   steel is higher than that for concrete
    (D)   none of the above

38   Design is concerned with——
    (A)   Selection of material
    (B)   Shape and size
    (C)   Arrangements of elements
    (D)   All of the above.

39   Is analysis of forces important in designing a machine element?
    (A)   Yes
    (B)   No
    (C)   May be
    (D)   Can’t say

40   In which of the following step we can change the size of member.
    (A)   Detailed drawing
    (B)   Modification
    (C)   Both A and B
    (D)   none of the above

41   Which of the following is not step of machine design?
    (A)   Recognition of need
    (B)   Mechanism
    (C)   Analysis of forces
    (D)   Safety of operation

42   To avoid failure which of the following is important.
    (A)   Reliability
    (B)   Wear resistance
    (C)   Strength
    (D)   None of the above

43   Need =>Mechanism =>Analysis of forces =>———=> Design of element.
    (A)   Modification
    (B)   Production
    (C)   Quality checking
    (D)   Material selection

44   Is quality checking part of machine designing?
    (A)   Yes
    (B)   No
    (C)   May be
    (D)   Can’t say

45   To selection of material——.
    (A)   Designer should have a deep knowledge about properties of material.
    (B)   Knowledge about properties is not important.
    (C)   Both A and B can be done.
    (D)   None of the above

46   What will happened if standard parts are used?
    (A)   Overall cost reduces
    (B)   Develops machine work effectively
    (C)   Both A and B
    (D)   None of the above

47   Which of the following parameters can be obtained by tension test of a standard specimen?
    (A)   Proportional limit
    (B)   Yield strength
    (C)   Percentage reduction in area
    (D)   All of the above

48   Yield strength is defined as the maximum stress at which a marked increases in elongation occurs without increases in
    (A)   Load
    (B)   Strength
    (C)   Toughness
    (D)   Hardness

49   Which of the following measuring the stiffness?
    (A)   Modulus of elasticity
    (B)   Modulus of plasticity
    (C)   Resilience
    (D)   Toughness

50   Modulus of resilience is defined as
    (A)   Strain energy per unit volume
    (B)   Strain energy per unit area
    (C)   Independent of strain energy
    (D)   None of the above

51   Malleability increases with temperature while ductility decreases with the temperature
    (A)   TRUE
    (B)   FALSE

52   Calculate the diameter of pin from shear consideration with maximum shear stress allowed is 40kN/mm² and an axial tensile force of 50kN is acting on the rod.
    (A)   40
    (B)   50
    (C)   60
    (D)   70

53   For an elliptical hole on a flat plate, if width of the hole in direction of the load decrease, Stress Concentration Factor will be
    (A)   Increased
    (B)   Decreased
    (C)   Remains constant
    (D)   Can’t be determined. Varies from material to material

54   In which of the following case stress concentration factor is ignored?
    (A)   Ductile material under static load
    (B)   Ductile material under fluctuating load
    (C)   Brittle material under static load
    (D)   Brittle material under fluctuating load

55   Use of multiple notches in a V shaped flat plate will be
    (A)   Reduce the stress concentration
    (B)   Increase the stress concentration
    (C)   No effect
    (D)   Cannot be determined

56   Which of the following reduces the stress concentration?
    (A)   Use of multiple notches
    (B)   Drilling additional holes
    (C)   Removal of undesired material
    (D)   Each of the mentioned

57   Which of the following is measure of stiffness?
    (A)   Modulus of elasticity
    (B)   Modulus of plasticity
    (C)   Resilience
    (D)   Toughness

58   irregularities present in the component and no changes of the cross section.
    (A)   TRUE
    (B)   FALSE

59   Stress Concentration Factor is the ratio of nominal stress obtained by elementary equations for minimum cross-section and highest value of actual stress near discontinuity.
    (A)   TRUE
    (B)   FALSE

60   If a flat plate with a circular hole is subjected to tensile force, then its theoretical stress concentration factor is?
    (A)   2
    (B)   3
    (C)   4
    (D)   1

61   For an elliptical hole on a flat plate, if width of the hole in direction of the load decrease, Stress Concentration Factor will——
    (A)   Increase
    (B)   Decrease
    (C)   Remains constant
    (D)   can’t be determined. Varies from material to material

62   Is it logical to use fluid analogy to understand the phenomenon of stress concentration?
    (A)   TRUE
    (B)   FALSE

63   Use of multiple notches in a V shaped flat plate will
    (A)   Reduce the stress concentration
    (B)   Increase the stress concentration
    (C)   No effect
    (D)   Cannot be determined

64   A flat plate 30mm wide and “t” mm wide is subjected to a tensile force of 5kN. The plate has a circular hole of diameter 15mm with the center coinciding with the diagonal intersection point of the rectangle. If stress concentration factor=2.16, find the thickness of the plate if maximum allowable tensile stress is 80N/mm².
    (A)   8mm
    (B)   9mm
    (C)   10mm
    (D)   12mm

65   The fatigue stress concentration factor is defined as
    (A)   The ratio of endurance limit with stress concentration to the endurance limit without stress concentration
    (B)   The ratio of endurance limit without stress concentration to the endurance limit with stress concentration
    (C)   The product of the endurance limits with and without stress concentration
    (D)   All of the above.

66   Stress may be defined as _________
    (A)   Force per unit volume
    (B)   Force per unit length
    (C)   Force per unit area
    (D)   None of these

67   The forces acting on the bar as shown in the given figure introduce _________?

    (A)   Tensile stress
    (B)   Compressive stress
    (C)   Shear stress
    (D)   None of these

68   The property by which a body returns to its original shape after removal of the force is called __________
    (A)   Plasticity
    (B)   Elasticity
    (C)   Ductility
    (D)   Malleability

69   Which law is also called as the elasticity law, which states that stress is proportional to the strain within the elastic limit?
    (A)   Bernoulli’s law
    (B)   Stress law
    (C)   Hooke’s law
    (D)   Poisson’s law

70   A member which does not regain its original shape after removal of the load producing deformation is said __________
    (A)   Plastic
    (B)   Elastic
    (C)   Rigid
    (D)   None of the mentioned

71   As the elastic limit reaches, tensile strain __________
    (A)   Increases more rapidly
    (B)   Decreases more rapidly
    (C)   Increases in proportion to the stress
    (D)   Decreases in proportion to the stress

72   The dimension of strain is?
    (A)   LT-2
    (B)   N/m2
    (C)   N
    (D)   Dimensionless

73   Live loads, with time can vary in_________
    (A)   Magnitude
    (B)   Position
    (C)   Neither position nor magnitude
    (D)   Position as well as magnitude

74   What is the first step in the ‘General procedure of machine design’?
    (A)   Analysis of forces
    (B)   Material Selection
    (C)   Need or aim
    (D)   Detailed drawing

75   Sizes of machine components are decided in which stage of general procedure of machine design?
    (A)   Material selection
    (B)   Detail drawing
    (C)   Design of element
    (D)   Analysis of forces

76   Detailed drawings of designed machine elements are needed by workers to machine/fabricate/assemble the machine elements. Is this statement true.
    (A)   TRUE
    (B)   FALSE

77   When you design a machine element you should make use of standard elements as much as possible?
    (A)   TRUE
    (B)   FALSE

78   A machine designer should consider the following factors among others
    (A)   Workshop facilities
    (B)   Selection of materials
    (C)   Types of loads and stresses
    (D)   All of the above

79   Compressive stress acting on the contact area between two components having no relative motion between them is known as crushing stress
    (A)   TRUE
    (B)   FALSE

80   At the neutral axis, bending stress is _____
    (A)   Minimum
    (B)   Maximum
    (C)   Zero
    (D)   Constant

81   What is the product of force and radius?
    (A)   Twisting shear
    (B)   Turning shear
    (C)   Turning moment
    (D)   Tilting moment

82   What is the unit of the Stress and strain
    (A)   N/mm2 and mm
    (B)   N and mm 
    (C)   N/mm and mm2
    (D)   N/mm2 and No unit

83   Stress is
    (A)   External force
    (B)   Internal resistive force
    (C)   Axial force
    (D)   Radial force

84   The stress which acts in a direction perpendicular to the area is called ____________
    (A)   Shear stress
    (B)   Normal stress
    (C)   Thermal stress
    (D)   None of the mentioned

85   Which of these are types of normal stresses?
    (A)   Tensile and compressive stresses
    (B)   Tensile and thermal stresses
    (C)   Shear and bending
    (D)   Compressive and plane stresses

86   The stress induced in a body, when subjected to two equal and opposite forces which are acting tangentially across the resisting section resulting the shearing of the body across its section is called ____________
    (A)   Bending stress
    (B)   Compressive stress
    (C)   Shear strain
    (D)   Shear stress

87   Following are the basic types of stress except
    (A)   Tensile stress
    (B)   Compressive stress
    (C)   Shear stress
    (D)   Volumetric stress

88   The deformation per unit length is called
    (A)   Strain
    (B)   Stress
    (C)   Elasticity
    (D)   None of these

89   The ability of the material to deform without breaking is called
    (A)   Elasticity
    (B)   Plasticity
    (C)   Creep
    (D)   None of these

90   The stress at which extension of a material takes place more quickly as compared to increase in load, is called
    (A)   No elastic zone
    (B)   Plastic point
    (C)   Yield point
    (D)   Breaking point

91   A perfectly elastic body
    (A)   Can move freely
    (B)   Has perfectly smooth surface
    (C)   Is not deformed by any external surface
    (D)   Recovers its original size and shape when the deforming force is removed.

92   When a section is subjected to two equal and opposite forces tangentially to the section, the stress produced is known as
    (A)   Tensile stress
    (B)   Lateral stress
    (C)   Shear stress
    (D)   No stress

93   In the stress strain diagram shown in the figure, what does the letter D represent?

    (A)   Upper yield point
    (B)   Lower yield point
    (C)   Ultimate limit
    (D)   Braking point

94   Match the materials with the stress-strain curves in the given figure?

    (A)   A- Cast iron, B- Plastic, C- Mild steel
    (B)   A- Cast iron, B- Mild steel, C- Plastic
    (C)   A- Mild steel, B- Cast iron, C- Plastic
    (D)   A- Plastic, B- Cast iron, C- Mild steel

95   An example of ductile material is
    (A)   Cast iron
    (B)   Rubber
    (C)   Glass
    (D)   Mild steel

96   An example of brittle material
    (A)   Cast iron
    (B)   Rubber
    (C)   Glass
    (D)   Mild steel

97   Hooke’s law holds good up to
    (A)   Yield point
    (B)   Limit of proportionality
    (C)   Breaking point
    (D)   Elastic limit

98   Strain is defined as the ratio of
    (A)   Change in volume to original volume
    (B)   Change in length to original length
    (C)   Change in cross-sectional are to original cross-sectional area
    (D)   Any one of the above

99   It equal and opposite forces applied to a body tend to elongate it, the stress so produced is called
    (A)   Internal resistance
    (B)   Tensile stress
    (C)   Compressive stress
    (D)   Working stress

100   A thin mild steel wire is loaded by adding loads in equal increments till it breaks. The extensions noted with increasing loads will behave as under
    (A)   Uniform throughout
    (B)   Increase uniformly
    (C)   First increase and then decrease
    (D)   Increase uniformly first and then increase rapidly

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