Theory of Machines – Mechanical Engineering Multiple Choice Questions
126. In a rigid link OA, velocity of A w.r.t. will be
(a) parallel to OA
(b) perpendicular to OA
(c) at 45° to OA
(d) along AO
(e) along OA.
Ans: b
127. Two systems shall be dynamically equivalent when
(a) the mass of two are same
(b) e.g. of two coincides
(c) M.I. of two about an axis through e.g. is equal
(d) all of the above
(e) none of the above.
Ans: d
128. The velocity of any point in mechanism relative to any other point on the mechanism on velocity polygon is represented by the line
(a) joining the corresponding points
(b) perpendicular to line as per (a)
(c) not possible to determine with these data
(d) at 45° to line as per (a)
(e) none of the above.
Ans: a
129. The absolute acceleration of any point P in a link about center of rotation 0 is
(a) along PO
(b) perpendicular to PO
(c) at 45° to PO
(d) along OP
(e) none of the above.
Ans: e
130. Angular acceleration of a link can be determined by dividing the
(a) centripetal component of acceleration with length of link
(b) tangential component of acceleration with length of link
(c) resultant acceleration with length of link
(d) all of the above
(e) none of the above.
Ans: b
131. Corioli’s component of acceleration exists whenever a point moves along a path that has
(a) linear displacement
(b) rotational motion
(c) tangential acceleration
(d) centripetal acceleration
(e) none of the above.
Ans: b
132. The direction of Corioli’s component of acceleration is the direction
(a) of relative velocity vector for the two coincident points rotated by 90° in the direction of the angular velocity of the rotation of the link
(b) along the centripetal acceleration
(c) along tangential acceleration
(d) along perpendicular to angular velocity
(e) none of the above.
Ans: a
133. In a shape mechanism, the Corioli’s component of acceleration will
(a) not exist
(b) exist
(c) depend on position of crank
(d) unpredictable
(e) none of the above.
Ans: b
134. The magnitude of tangential acceleration is equal to
(a) velocity2 x crank radius
(b) velocity vcrankradius
(c) (velocity/crankradius)
(d) velocity x crank radius2
(e) none of the above.
Ans: b
135. Tangential acceleration direction is
(a) along the angular velocity
(b) opposite to angular velocity
(c) may be any one of these
(d) perpendicular to angular velocity
(e) none of the above.
Ans: c
136. Coriolis component is encountered in
(a) quick return mechanism of sharper
(b) four bar chain mechanism
(c) slider crank mechanism
(d) (a) and (c) above
(e) all of the above.
Ans: a
137. Klein’s construction gives a graphics construction for
(a) slider-crank mechanism
(b) velocity polygon
(c) acceleration polygon
(d) four bar chain mechanism
(e) angular acceleration.
Ans: c
138. Klein’s construction can be used to determine acceleration of various parts when the crank is at
(a) inner dead center
(b) outer dead center
(c) right angles to the link of the stroke
(d) at 45° to the line of the stroke
(e) all of the above.
Ans: e
139. The number of load centers in a crank driven slider crank mechanism are
(a) 0
(b) 2
(c) 4
(d) 6
(e) may be any number depending upon position of mechanism.
Ans: b
140. Corioli’s component acts
(a) perpendicular to sliding surfaces
(b) along sliding surfaces
(c) somewhere in between above two
(d) unpredictable
(e) none of the above.
Ans: a
141. The sense of Corioli’s component is such that it
(a) leads the sliding velocity vector by 90°
(b) lags the sliding velocity vector by 90°
(c) is along the sliding velocity vector
(d) leads the sliding velocity vector by 180°
(e) none of the above.
Ans: a
142. Klein’s construction can be used when
(a) crank has a uniform angular velocity
(b) crank has non-uniform velocity
(c) crank has uniform angular acceleration
(d) crank has uniform angular velocity and angular acceleration
(e) there is no such criterion.
Ans: a
143. Klein’s construction is useful to determine
(a) velocity of various parts
(b) acceleration of various parts
(c) displacement of various parts
(d) angular acceleration of various parts
(e) all of the above.
Ans: b
144. A circle passing through the pitch point with its center at the center of cam axis is known as
(a) pitch circle
(b) base circle
(c) prime circle
(d) outer circle
(e) cam circle.
Ans: c
145. The pressure angle of a cam depends upon
(a) offset between center lines of cam and follower
(b) lift of follower
(c) angle of ascent
(d) sum of radii of base circle and roller follower
(e) all of the above.
Ans: e
146. Cam size depends upon
(a) base circle
(b) pitch circle
(c) prime circle
(d) outer circle
(e) none of the above.
Ans: a
147. Cylindrical cams can be classified as
(a) circular
(b) tangent
(c) reciprocating
(d) all of the above
(e) none of the above.
Ans: e
148. The maximum value of the pressure angle in case of cam is kept as
(a) 10°
(b) 14°
(c) 20°
(d) 30°
(e) 25°.
Ans: d
149. For the same lift and same angle of ascent, a smaller base circle will give
(a) a small value of pressure angle
(b) a large value of pressure angle
(c) there is no such relation with pressure angle
(d) something else
(e) none of the above is true.
Ans: b
150. Cam angle is defined as the angle
(a) during which the follower returns to its initial position
(b) of rotation of the cam for a definite displacement of the follower
(c) through which, the cam rotates during the period in which the follower remains in the highest position
(d) moved by the cam from the instant the follower begins to rise, till it reaches its highest position
(e) moved by the cam from beginning of i ascent to the termination of descent.
Ans: b
151. Angle of descent of cam is defined as the angle
(a) during which the follower returns to its initial position
(b) of rotation of the cam for a definite displacement of the follower
(c) through which the cam rotates during the period in which the follower remains in the highest position
(d) moved by the cam from the instant the follower begins to rise, till it reaches its highest position
(e) moved by the cam from beginning of ascent to the termination of descent.
Ans: a
152. Angle of action of cam is defined as the angle
(a) during which the follower returns to its initial position
(b) of rotation of the cam for a definite displacement of the follower
(c) through which the cam rotates during the period in which the follower remains in the highest position
(d) moved by the cam from the instant the follower begins to rise, till it reaches its highest position
(e) moved by the cam from beginning of ascent to the termination of descent.
Ans: e
153. Angle of dwell of cam is defined as the angle
(a) during which the follower returns to its initial position
(b) of rotation of the cam for definite displacement of the follower
(c) through which the cam rotates during the period in which the follower remains in the highest position
(d) moved by the cam from the instant the follower begins to rise, till it reaches its highest position
(e) moved by the cam from a beginning of ascent to the termination of descent.
Ans: c