Elements of Machine Design-11

  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

Design of Bolted and Welded joints

1   The bearing pressure is exerted at right angles to the shaft axis in a
    (A)   Foot step bearing
    (B)   Collar bearing
    (C)   Radial bearing
    (D)   Taper roller bearing
2   The basic load rating of a ball bearing is
    (A)   the maximum static radial load that can be applied without causing any plastic deformation of bearing components
    (B)   the radial load at which 90% of the group of apparently identical bearings run for one million revolutions before the first evidence of failure
    (C)   the maximum radial load that can be applied during operation without any plastic deformation of bearing components
    (D)   a combination of radial and axial loads that can be applied without any plastic deformation
3   The rating life of a group of apparently identical bearings is defined as the number of revolutions made before the first evidence of fatigue crack by ____ percent of the bearings of the group
    (A)   100
    (B)   95
    (C)   90
    (D)   66.66
4   Which is not the feature of gear design done by invoking the basic Lewis equation?
    (A)   each tooth is considered as a cantilever beam
    (B)   static strength of tooth is considered in bending
    (C)   dynamic effects due to high pitch line velocities are not taken into account
    (D)   allowance is made for the stress concentration at the root
5   Lewis correlation is used to determine
    (A)   tensile stress in bending
    (B)   compressive stress in bending
    (C)   fatigue stress
    (D)   shear stress
6   Lewis equation is applied
    (A)   Only to gear
    (B)   Only to pinion
    (C)   To weaker of the pinion or gear
    (D)   To stronger of the pinion and gear
7   In the Lewis equation, the working stress depends upon
    (A)   Material of the tooth only
    (B)   Pitch line velocity only
    (C)   Load conditions as well as the material of the tooth
    (D)   Pitch line velocity, load conditions and material of the tooth
8   The permissible working stress in the Lewis equation
    (A)   Increases with increase in pitch line velocity
    (B)   Decreases with increase in pitch line velocity
    (C)   Increases upto a certain value of pitch line velocity and then starts decreasing
    (D)   Is independent of pitch line velocity
9   In the formulation of Lewis equation for toothed gearing, it is assumed that tangential tooth load acts on the
    (A)   Pitch point
    (B)   Tip of the tooth
    (C)   Root of the tooth
    (D)   Whole face of the tooth
10   In the Lewis equation W=σw. Pc.y.b, the strength factor is given by the product
    (A)   σw.y
    (B)   σw.b
    (C)   Pc.y
    (D)   Pc. b
11   Identify the bearing
    (A)   Ball bearing
    (B)   Journal bearing
    (C)   Needle bearing
    (D)   Tapered roller bearings
12   Identify the bearing shown in the figure
    (A)   Ball bearing
    (B)   Journal bearing
    (C)   Needle bearing
    (D)   Tapered roller bearings
13   Identify the bearing shown in the figure
    (A)   Ball bearing
    (B)   Journal bearing
    (C)   Needle bearing
    (D)   Tapered roller bearings
14   Identify the bearing shown in the figure
    (A)   Ball bearing
    (B)   Journal bearing
    (C)   Needle bearing
    (D)   Tapered roller bearings
15   Which bearing does the image represents?
    (A)   Hydrostatic bearing
    (B)   Hydrodynamic bearing
    (C)   Ball bearing
    (D)   Roller bearing
16   In hydrostatic bearings
    (A)   The Oil film pressure is generated only by the rotation of the journal
    (B)   The oil film is maintained by supplying oil under pressure
    (C)   Do not require external supply of lubricant
    (D)   Grease is used for lubrication
17   In hydrodynamic bearings
    (A)   The oil film pressure is generated only by the rotation of the journal
    (B)   The oil film is maintained by supplying oil under pressure
    (C)   Do not require external supply of lubricant
    (D)   Grease is used for lubrication
18   Anti-friction bearings are lubricated by charcoal.
    (A)   TRUE
    (B)   FALSE
19   In a hydrodynamic lubricated bearing
    (A)   there is a thick film of lubricant between the journal and the bearing
    (B)   there is a thin film of lubricant between the journal and the bearing
    (C)   there is no lubricant between the journal and the bearing
    (D)   the lubricant is forced between the journal and the bearing, by external pressure
20   The rolling contact bearings are known as
    (A)   thick lubricated bearings
    (B)   plastic bearings
    (C)   thin lubricated bearings
    (D)   antifriction bearings

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