Machine Design MCQ Objective Question and Answers Part 3

Machine Design Multiple choice Objective Question useful for technical Aptitude test.

Machine Design MCQ : Part 1 | Part 2 | Part 3 | Part 4

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 up to 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

76. A tapered key which fits in a keyway in the hub and is flat on the shaft, is known as
(a) wood-ruff key
(b) feather key
(c) flat saddle key
(d) gib head key
(e) hollow saddle key.
Ans: c

77. Fibrous fracture occurs in
(a) ductile material
(b) brittle material
(c) elastic material
(d) hard material
(e) all of the above.
Ans: a

78. Turn buckle has
(a) right hand threads on bout ends
(b) left hand threads on both ends
(c) left hand threads on one end and right hand threads on other end
(d) no threads
(e) threads in middle portion.
Ans: c

79. Eye bolts are used for
(a) foundation purposes
(b) locking devices
(c) absorbing shock and vibrations
(d) transmission of power
(e) lifting and transportation of machines and cubicles.
Ans: e

80. Elastic nut is a locking device in which
(a) one small 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) hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed 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 pin splitted and bent in reverse direction at other end
(e) none of the above,
Ans: c

81. If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation
(a) 102 d
(b) 124 d
(c) 138 d
(d) 151 d
(e) 168 d.
Ans: e

82. If threads on a bolt are left hand, threads on nut will be
(a) right hand with same pitch
(b) left hand with same pitch
(c) could be left or right hand
(d) right hand with fine pitch
(e) left hand with fine pitch.
Ans: b

83. Taper usually provided on cotter is
(a) 1 in 5
(b) 1 in 10
(c) 1 in 24
(d) 1 in 40
(e) 1 in 50.
Ans: c

84. Applications in which stresses are encountered in one direction only uses following type of threads
(a) metric
(b) buttress
(c) acme
(d) square
(e) BSW.
Ans: b

85. The draw of cotter need not exceed
(a) 3 mm
(b) 5 mm
(c) 10 mm
(d) 20 mm
(e) 25 mm.
Ans: a

86. A bench vice has following type of threads
(a) metric
(b) square
(c) buttress
(d) acme
(e) BSW.
Ans: d

87. The valve rod in a steam engine is connected to an eccentric rod by
(a) cotter joint
(b) bolted joint
(c) kunckle joint
(d) universal coupling
(e) gib and cotter joint.
Ans: c

88. Split 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 screw
(c) a hard fiber 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 pin splitted and bent in reverse direction at the other end
(e) none of the above.
Ans: b

89. Taper on the cotter and slot is provided
(a) on both the sides
(b) on one side only
(c) on none of the sides
(d) may be provided anywhere
(e) none of the above.
Ans: b

90. The function of cutting oil when threading a pipe is to
(a) provide cooling action
(b) lubricate the dies
(c) help remove chips
(d) all of the above
(e) none of the above.
Ans: d

91. Silver-based solder is used for
(a) flaring
(b) brazing
(c) soft soldering
(d) fusion welding
(e) none of the above.
Ans: b

92. For tight leakage joints, following type of thread is best suited
(a) metric
(b) buttress
(c) square
(d) acme
(e) NPT (national pipe threads).
Ans: e

93. In order to permit the thermal expansion/contraction of tubing, it should be
(a) crimped
(b) honed
(c) flared
(d) bent
(e) none of the above.
Ans: d

94. A tube has the following advantage over pipe
(a) lighter and easier to handle
(b) greater shock absorption
(c) smoother inside walls
(d) all of the above
(e) none of the above.
Ans: d

95. The strap end of a connecting rod of steam engine is joined by
(a) gib of cotter joint
(b) sleeve and cotter joint
(c) spigot socket cotter joint
(d) knuckle joint
(e) universal coupling.
Ans: a

96. A backing ring is used inside the pipe joint when making a
(a) butt weld
(b) fillet weld
(c) sleeve weld
(d) socket weld
(e) tube weld.
Ans: a

97. The shear plane in case of bolts should
(a) be across threaded portion of shank
(b) be parallel to axis of bolt
(c) be normal to threaded portion of shank
(d) never be across the threaded portion
(e) none of the above.
Ans: d

97. Castle 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 is middle of nut and then slot reduced by tightening a screw
(c) a hard fiber 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 pin spitted and bent in reverse direction at other end
(e) none of the above.
Ans: d

98. When a nut is tightened by plaping a washer below it, the bolt will be subjected to following type of loads
(a) compression
(b) tension
(c) shear
(d) combined loads
(e) all of the above.
Ans: b

99. Gear box is used
(a) to produce torque
(b) for speed reduction
(c) to obtain variable speeds
(d) to increase efficiency of system
(e) to damp out vibrations.
Ans: c

100. The edges of the plates for cylindrical vessels are usually bevelled to an angle of 80° for
(a) reducing stress concentration
(b) ease of manufacture
(c) safety
(d) fullering and caulking
(e) all of the above.
Ans: d

Machine Design MCQ : Part 1 | Part 2 | Part 3 | Part 4