Engineering Questions with Answers - Multiple Choice Questions

# Machine Kinematics Questions and Answers – Double Slider Crank Chain & its Inversions

1 - Question

Which of the following instruments is used to draw ellipses?
a) Elliptical trammels
b) Slotted lever and crank
c) Gnome engine
d) Oldham’s coupling

Explanation: Elliptical trammel is an instrument which is an inversion of a double slider crank chain. It is mainly used to draw ellipses.

2 - Question

Elliptical trammels are used to convert reciprocating motion into rotary motion.
a) True
b) False

Explanation: Elliptical trammels are used to draw ellipses; scotch yoke mechanisms are used to convert rotary motion into reciprocating motion.

3 - Question

How inversion is obtained in an elliptical trammel?
a) Fixing the slotted plate
b) Fixing the sliders
c) Fixing the turning pairs
d) Fixing the pin

Explanation: An elliptical trammel is an instrument which is an inversion of a double slider crank chain, here the inversion is obtained by fixing the slotted plate. It is used to draw ellipses.

4 - Question

In the given figure, 1 and 2 are sliders, 3 is a bar and 4 is a fixed slotted plate, identify the mechanism. a) Elliptical trammel
b) Scotch yoke mechanism
c) Oldham’s coupling
d) Gnome engine

Explanation: In the given figure, the slotted lever is fixed and there are two sliders, hence it is a double slider crank chain, since the slotted plate is fixed, it is an inversion. This inversion is known as elliptical trammels.

5 - Question

In the given figure if P is not the midpoint of the line connecting 1 and 2, what is the locus of P? a) Ellipse
b) Straight line
c) Parabola
d) Rectangular hyperbola

Explanation: The given figure represents an elliptical trammel, in an elliptical trammel any point on the bar traces a path which is an ellipse, hence the locus of P is ellipse.

6 - Question

In the given figure if P is the midpoint of the line connecting 1 and 2, what is the locus of P? a) Ellipse
b) Circle
c) Parabola
d) Rectangular hyperbola

Explanation: The given figure represents an elliptical trammel, in an elliptical trammel any point on the bar traces a path which is an ellipse, hence the locus of P is ellipse, but in this case P is the midpoint hence, the locus of P will be a circle.

7 - Question

Which of the mechanism is used to convert rotary motion into a reciprocating motion?
a) Elliptical trammel
b) Scotch yoke mechanism
c) Oldham’s coupling
d) Gnome engine

Explanation: Scotch yoke mechanism is an example of an inversion of a double slider crank chain, this mechanism is used to convert rotary motion into reciprocating motion.

8 - Question

In Scotch yoke mechanism, the crank is fixed in order to obtain the inversion.
a) True
b) False

Explanation: In scotch yoke mechanism there are in total 4 links, one is Crank and one is frame. Inversion can be obtained by fixing either of the remaining two links.

9 - Question

Which of the following mechanism is used for connecting two parallel shafts whose axes are at a small distance apart?
a) Elliptical trammel
b) Scotch yoke mechanism
c) Oldham’s coupling
d) Gnome engine

Explanation: Oldham’s coupling is an instrument which is an inversion of double slider crank chain, this is used to connect two parallel shafts whose axes are at a small distance apart.

10 - Question

Which of the following link is fixed to obtain inversion in Oldham’s coupling?
a) Driving shaft
b) Flange
c) Supporting frame
d) Driven shaft

Explanation: The shafts are coupled in such a way that if one shaft rotates, the other shaft also rotates at the same speed. This inversion is obtained by fixing the link which corresponds to Supporting frame.

11 - Question

How many turning pairs are there in a double slider crank chain?
a) 1
b) 2
c) 3
d) 4

Explanation: Double slider crank chain is a kinematic chain which consists of two turning pairs, as a result it is called double slider crank chain.

12 - Question

A double slider crank chain has one pair of each sliding and turning pairs.
a) True
b) False

Explanation: In a double slider crank chain, there are two turning pairs and two sliding pairs. In a single slider crank chain there is one sliding pair and three turning pairs.

13 - Question

How many sliding pairs are there in a double slider crank chain?
a) 1
b) 2
c) 3
d) 4

Explanation: Double slider crank chain is a kinematic chain which consists of two sliding pairs, as a result it is called double slider crank chain.

14 - Question

In which of the following mechanisms inversion is obtained by fixing the cylinder?
a) Pendulum pump
b) Gnome engine
c) Double slider crank chain
d) Oscillating cylinder

Explanation: Pendulum pump also known as the bull engine is an inversion of single slider crank chain, here inversion is obtained by fixing the cylinder.

15 - Question

Which of the following is not an inversion of double slider crank chain?
a) Elliptical trammels
b) Scotch yoke mechanism
c) Oldham’s coupling
d) Gnome engine