Theory of Machines – Mechanical Engineering Multiple Choice Questions
76. TJie horse power transmitted by a belt is dependent upon
(a) tension on tight side of belt
(b) tension on slack side of belt
(c) radius of pulley
(d) speed of pulley
(e) all of the above.
Ans: e
77. The locus of a point on a thread unwound from a cylinder will be
(a) a straight line
(b) a circle
(c) involute
(d) cycloid
(e) helix.
Ans: c
78. To transmit power from one rotating shaft to another whose axes are neither parallel nor intersecting, use
(a) spur gear
(b) spiral gear
(c) bevel gear
(d) worm gear
(e) crown gear.
Ans: d
79. For S.H.M. cam, the acceleration of the follower at the ends of the stroke and aimidstroke respectively, is
(a) maximum and zero
(b) zero and maximum
(c) minimum and maximum
(d) zero and minimum
(e) maximum and minimum.
Ans: a
80. Throw of a cam is the maximum distance of the follower from
(a) base circle
(b) pitch circle
(c) root circle
(d) prime circle
(e) inner circle.
Ans: a
81. To obviate axial thrust, following gear drive is used
(a) double helical gears having opposite teeth
(b) double helical gears having identical teeth
(c) single helical gear in which one of the teeth of helix angle a is more
(d) mutter gears
(e) none of the above.
Ans: a
82. Which of the following is false statement in respect of differences between machine and structure
(a) Machines transmit mechanical work, whereas structures transmit forces
(b) In machines, relative motion exists be-tween its members, whereas same does hot exist in case of structures
(c) Machines modify movement and work, whereas structures modify forces
(d) Efficiency of machines as well as structures is below 100%
(e) Machines are run by electric motors, but structures are not.
Ans: d
83. If D1 and D2 be the diameters of driver and driven pulleys, then belt speed is proportional to
(a) D1/D2
(b) D2/D1
(C) D1-D2.
(d) D1
(e) D1+D2.
Ans: d
84. Typewriter constitutes
(a) machine
(b) structure
(c) mechanism
(d) inversion
(e) none of the above.
Ans: c
85. Lower pairs are those which have
(a) point or line contact between the two elements when in motion
(b) surface contact between the two elements when in motion
(c) elements of pairs not -held together mechanically
(d) two elements that permit relative motion
(e) none of the above.
Ans: b
86. A point on a link connecting double slider crank chain traces a
(a) straight line
(b) circle
(c) parabola
(d) hyperbola
(e) ellipse.
Ans: e
87. A pantograph is a mechanism with
(a) lower pairs
(b) higher pairs
(c) rolling pairs
(d) turning pairs
(e) spherical pairs.
Ans: a
88. Kinematic pairs are those which have
(a) point or line contact between the two elements when in motion
(b) surface contact between the two elements when in motion
(c) elements of pairs not held together mechanically
(d) two elements that permit relative motion
(e) none of the above.
Ans: d
89. If the opposite links of a four bar linkage are equal, the links will always form a
(a) triangle
(b) rectangle
(c) parallelogram
(d) pentagon
(e) trapezoid.
Ans: c
90. Higher pairs are those which have
(a) point or line contact between the two elements when in motion
(b) surface contact between the two elements when in motion
(c) elements of pairs not held together mechanically
(d) two elements that permit relative motion
(e) none of the above.
Ans: a
91. A cam mechanism imparts following motion
(a) rotating
(b) oscillating
(c) reciprocating
(d) all of the above
(e) none of the above.
Ans: d
92. A cam with a roller follower would con statute following type of pair
(a) lower pair
(b) higher pair
(c) open pair
(d) close pair
(e) cam pair.
Ans: b
93. The approximate straight line mechanism is a
(a) four bar linkage
(b) 6 bar linkage
(c) 8 bar linkage
(d) 3 bar linkage
(e) 5 bar linkage.
Ans: a
94. Open pairs are those which have
(a) point or line contact between the two elements when in motion
(b) surface contact between the two elements when in motion
(c) elements of pairs not held together mechanically
(d) two elements that permit relative motion
(e) none of the above.
Ans: c
95. Peaucellier mechanism has
(a) eight links
(b) six links
(c) four links
(d) twelve links
(e) five links.
Ans: a
96. Hart mechanism has
(a) eight links
(b) six links
(c) four links
(d) twelve links
(e) five links.
Ans: b
97. A chain comprises of 5 links having 5 joints. Is it kinematic chain ?
(a) yes
(b) no
(c) it is a marginal case
(d) data are insufficient to determine it
(e) unpredictable.
Ans: b
99. The main disadvantage of the sliding pair is that it is
(a) bulky
(b) wears rapidly
(c) difficult to manufacture
(d) (a) and (b) above
(e) (a) and (c) above.
Ans: d
100. For a kinematic chain to be considered as mechanism
(a) two links should be fixed
(b) one link should be fixed
(c) none of the links should be fixed
(d) there is no such criterion
(e) none of the above.
Ans: b