Engineering Questions with Answers - Multiple Choice Questions
Machine Kinematics Questions and Answers – Single Slider Crank Chain and its Inversions – 2
1 - Question
A single slider crank chain is a _______
a) 4-link mechanism
b) 3-link mechanism
c) 2-link mechanism
d) 6-link mechanism
View Answer
Answer: a
Explanation: A single slider crank chain is a four link mechanism, any four link mechanisms has 4 links inclusive of higher and lower pairs.
2 - Question
Bull engine is an inversion of single slider crank chain.
a) True
b) False
View Answer
Answer: a
Explanation: In a bull engine the inversion is obtained by fixing the cylinder, thus it is an inversion of a single slider crank chain.
3 - Question
Find the ratio of the time of cutting to the time of return stroke from the following information: A crank and slotted lever mechanism used in a shaper has a centre distance of 0.300 m between the centre of oscillation of the slotted lever and the centre of rotation of the crank. The radius of the crank is 0.120 m.
a) 1.72
b) 1.65
c) 1.81
d) 1.79
View Answer
Answer: a
Explanation: We know that time of cutting stroke to the time of return stroke is given by
360-α/ α
Using trigonometric ratios we find that α =132.8°
therefore, Ratio = 1.72.
4 - Question
Find the inclination of the slotted bar with the vertical in degrees in the extreme position from the following information: In a crank and slotted lever quick return motion mechanism, the distance between the fixed centres is 0.240 m and the length of the driving crank is 0.120 m.
a) 30
b) 45
c) 60
d) 75
View Answer
Answer: a
Explanation: In a crank and slotted lever mechanism, symmetry can be observed. Using this symmetry and trigonometric ratios we find that
angle = 30 degrees.
5 - Question
Find the ratio of the time of cutting to the time of return stroke from the following information: In a crank and slotted lever quick return motion mechanism, the distance between the fixed centres is 0.240 m and the length of the driving crank is 0.120 m.
a) 3
b) 4.5
c) 3.2
d) 2
View Answer
Answer: d
Explanation: In a crank and slotted lever mechanism, symmetry can be observed. Using this symmetry and trigonometric ratios we find that vertical inclination of slotted bar is
angle = 30 degrees.
now 90- α/2 = 30
α=120 degrees
therefore ratio = 2.
6 - Question
Find the length of stroke if the length of the slotted bar is 0.45m and LOS passes through the free end of the lever. Length of driving crank = 0.12m, distance between fixe centres = 0.24m. Crank and slotted lever quick return motion mechanism.
a) 450mm
b) 400mm
c) 500mm
d) 475mm
View Answer
Answer: a
Explanation: We know that length of stroke is:
2x450xsin(90-α/2)
α=120 degrees,
therefore
length = 450mm.
7 - Question
Which of the following mechanism is mostly used in shaping and slotting machines?
a) Whitworth quick return motion mechanism
b) Bull engine
c) Crank and slotted lever quick return motion mechanism
d) Gnome engine
View Answer
Answer: a
Explanation: Whitworth quick return motion mechanism is mostly used in shaping and slotting machines, as in this mechanism a turning pair is fixed and the driving crank rotates at a uniform speed.
8 - Question
In Whitworth quick return motion mechanism, the driving crank is under an accelerated motion
a) True
b) False
View Answer
Answer: b
Explanation: In Whitworth quick return motion mechanism, the driving crank rotates at a uniform speed and is widely used in shaping and slotting machines.
9 - Question
Which of the following mechanism is used to convert reciprocating motion into rotary motion?
a) Whitworth quick return motion mechanism
b) Oscillating cylinder engine
c) Crank and slotted lever quick return motion mechanism
d) Gnome engine
View Answer
Answer: a
Explanation: Oscillating cylinder engine is used to convert reciprocating motion into rotary motion, the piston reciprocates and the cylinder oscillates about the pin.
10 - Question
How many cylinders are there in Gnome engine?
a) 4
b) 5
c) 6
d) 7
View Answer
Answer: d
Explanation: Rotary internal combustion engines were used in aviation. Now-a-days gas turbines are used in its place. It consists of seven cylinders in one plane and all revolves about fixed centre.