Engineering Questions with Answers - Multiple Choice Questions

# Machine Kinematics Questions and Answers – Velocity in Mechanisms – 2

1 - Question

The coriolis component of acceleration exists whenever a point moves along a path that has
a) linear displacement
b) rotational motion
c) gravitational acceleration
d) tangential acceleration

Explanation: When a point on one link is sliding along another rotating link such as in quick return motion mechanism, then Coriolis component of acceleration must be taken into account. It means for Coriolis component, rotational motion is required.

2 - Question

In a pantograph, all the pairs are
a) turning pairs
b) sliding pairs
c) spherical pairs
d) self-closed pairs

Explanation: Pantograph is an instrument used to reproduce to an enlarged or a reduced scale and as exactly as possible the path described by a given point. It consists of bars connected by turning pairs.

3 - Question

Which of the following mechanism is made up of turning pairs?
a) Scott Russel’s mechanism
b) Peaucellier’s mechanism
c) Hart’s mechanism
d) All of the mentioned

Explanation: Exact straight line motion mechanisms are made up of turning pairs. These mechanisms are as follows:
a) Peaucellier’s mechanism
b) Hart’s mechanism.

4 - Question

Scott Russel’s mechanism is made up of sliding pair.
a) True
b) False

Explanation: Exact straight line motion mechanisms consists of one sliding pair. The Scott Russell’s mechanism is of this type.

5 - Question

An exact straight line motion mechanism is a
a) Scott-Russell’s mechanism
b) Hart’s mechanism
c) Peaucellier’s mechanism
d) All of the mentioned

Explanation: All the mechanisms mentioned above consists of exact straight line motion. Scott-Russell’s mechanism consists of sliding pair whereas Peaucellier’s mechanism and Hart’s mechanism consists of turning pair.

6 - Question

Which of the following mechanism is an approximate straight line motion mechanism?
a) Watt’s mechanism
b) Grasshopper mechanism
c) Robert’s mechanism
d) All of the mentioned

Explanation: The mechanism that are approximate straight line motion are as follows:
a) Watt’s mechanism
b) Scott-Russell’s mechanism
c) Grasshopper mechanism
d) Robert’s mechanism
e) Tehebicheff’s mechanism.

7 - Question

The fundamental equation for correct steering is
a) sinɸ + sinα = b/c
b) cosɸ – sinα = c/b
c) cotɸ – cotα = c/b
d) tanɸ + cotα = b/c

Explanation: The condition for correct steering is that all the four wheels must turn about the same instantaneous centre.
The fundamental equation for correct steering is
cotɸ – cotα = c/b
where ɸ and α = Angle through which the axix of the outer wheel and inner wheel turns respectively
c = Distance between the pivots of the front axles
b = Wheel base.

8 - Question

The condition for correct steering of a Davis steering is
a) sinα = b/c
b) cosα = c/b
c) tanα = c/2b
d) cotα = c/2b

Explanation: In case of Davis steering gear, the condition for correct steering is
tanα = c/2b
where α = Angle of inclination of the links to the vertical.

9 - Question

The driving and driven shafts connected by a Hooke’s joint will have equal speeds, if
a) cosϴ = sinα
b) sinϴ = √tanα
c) tanϴ = √cosα
d) cotϴ = cosα

Explanation: A Hooke’s joint is used to connect two shafts, which are intersecting at a small angle. The speed of the driving and driven shafts will be equal, when
tanϴ = √cosα.

10 - Question

The Ackerman steering gear mechanism is preferred to the Davis steering gear mechanism because
a) whole of the mechanism in the Ackerman steering gear is on the back of the front wheels
b) the Ackerman steering gear consists of turning pairs
c) the Ackerman steering gear is most economical
d) both a and b