51. Shear stress theory is applicable for
(a) ductile materials
(b) brittle materials
(c) elastic materials
(d) all of the above
(e) none of the above.
Ans: a
52. A tap bolt
(a) has a head on one end and a nut fitted to the other
(b) has head at one end and other end fits into a tapped hole in the other part to be joined
(c) has both the ends threaded
(d) has pointed threads
(e) requires locking devices.
Ans: b
53. For applications involving high stresses in one direction only the following type of thread would be best suited
(a) ISO metric thread
(b) acme thread
(c) square thread
(d) buttress thread
(e) British Association thread.
Ans: d
54. The included angle in unified of American National threads is
(a) 60°
(b) 55°
(c) 47°
(d) 29°
(e) none of the above.
Ans: a
55. The function of a washer is to
(a) provide cushioning effect
(b) provide bearing area
(c) absorb shocks and vibrations
(d) provide smooth surface in place of rough surface
(e) act as a locking device.
Ans: b
56. Cap screws are
(a) similar to small size tap bolts except that a greater variety of shapes of heads are available
(b) slotted for a screw driver and generally used with a nut
(c) used to prevent relative motion be-tween parts
(d) provided with detachable caps
(e) similar to stud.
Ans: a
57. An alien bolt is
(a) self locking bolt
(b) same as stud
(c) provided with hexagonal depression in head
(d) used in high speed components
(e) provided with countersunk head.
Ans: c
58. The deflection of a cantilever beam under load W is 8. If its width is halved, then the deflection under load W will be
(a) 28
(b) 8/2
(c) 48
(d) 8/4
(e) none of the above.
Ans: c
59. Ball bearing type screws are found in following application
(a) screw jack
(b) aeroplane engines
(c) crane
(d) steering mechanism
(e) bench vice.
Ans: d
60. Set screws are
(a) similar to small size tap bolts except that a greater variety of shapes of heads are available
(b) slotted for a screw driver and generally used with a nut
(c) used to prevent relative motion be-tween parts
(d) similar to stud
(e) none of the above.
Ans: c
61. A self locking screw has
(a) fine threads
(b) coarse threads
(c) coefficient of friction > tangent of load angle
(d) hole for inserting split pin
(e) two nuts for locking.
Ans: c
62. The designation M 33 x 2 of a bolt means
(a) metric threads of 33 nos in 2 cm.
(b) metric threads with cross-section of 33 mm
(c) metric threads of 33 mm outside diameter and 2 mm pitch
(d) bolt of 33 mm nominal diameter having 2 threads per cm
(e) none of the above.
Ans: c
63. Machine screws are
(a) similar to small size tap bolts except that a greater variety of shapes of heads are available
(b) slotted for a screw driver and generally used with a nut
(c) used to prevent relative motion be-tween two parts
(d) similar to stud
(e) none of the above.
Ans: b
64. Rivets are generally specified by
(a) thickness of plates to be riveted
(b) length of rivet
(c) diameter of head
(d) nominal diameter
(e) all of the above.
Ans: d
65. The edges of a boiler plate are beveled to an angle of
(a) 30°
(b) 45°
(c) 60°
(d) 80°
(e) 85°
Ans: d
66. Which of the following is a permanent fastening ?
(a) bolts
(b) keys
(c) cotters
(d) rivets
(e) screws
Ans: d
67. In order to avoid tearing of the plate at edge, the distance from the center line of the rivet hole to the nearest edge of the plate in terms of dia. of rivet d should be equal to
(a) d
(b) 1.25 d
(c) 1.5 d
(d) 1.75 d
(e) 2 d
Ans: c
68. If the tearing efficiency of a riveted joint is 75%, then the ratio of diameter of rivet to the pitch is equal to
(a) 0.2
(b) 0.25
(c) 0.50
(d) 0.6
(e) 0.75
Ans: b
69. Transverse fillet welded joints are designed for
(a) tensile strength
(b) compressive strength
(c) shear strength
(d) bending strength
(e) torsional strength
Ans: a
70. Jam nut is a locking device in which
(a) one smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
(b) a slot is cut partly in middle of nut and then slot reduced by tightening a screw
(c) a hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
(d) through slots are made at top and a cotter-pin is passed through these and a hole in the bolt, and cotter splitted and bent in reverse direction at other end
(e) none of the above.
Ans: a
71. The pitch of threads on a Jock nut in comparison to pitch of nut is
(a) same
(b) coarser
(c) finer
(d) very coarse
(e) very fine
Ans: a
72.Buttress threads are usually found on
(a) screw cutting lathes
(b) feed mechanisms
(c) spindles of bench vices
(d) screw jack
(e) railway carriage couplings
Ans: e
73. In order to obtain bolt of uniform strength
(a) increase shank diameter
(b) increase its length
(c) drill an axial hole through head upto threaded portion so that shank area is equal to root area of thread
(d) tighten die bolt properly
(e) all of the above.
Ans: c
74. A key capable of tilting in a recess milled out in a shaft is known as
(a) wood-ruff key
(b) feather key
(c) flat saddle key
(d) gib head key
(e) hollow saddle key
Ans: a
75. A key made from a cylindrical disc having segmental cross-section, is known as
(a) wood-ruff key
(b) feather key
(c) flat saddle key
(d) gib head key
(e) hollow saddle key
Ans: a