Engineering Questions with Answers - Multiple Choice Questions
Machine Dynamics MCQ – Swaying Couple
1 - Question
The unbalanced forces along the line of stroke for the two cylinders constitute a ______ about the centre line between the cylinders.
a) Tension
b) Compression
c) Torsion
d) Couple
View Answer
Answer: d
Explanation: The unbalanced forces along the line of stroke for the two cylinders constitute a couple about the centre line between the cylinders. This couple is known as swaying couple as it has a swaying effect.
2 - Question
This couple has swaying effect about a horizontal axis.
a) True
b) False
View Answer
Answer: b
Explanation: This couple has swaying effect about a vertical axis, and tends to sway the engine alternately in clockwise and anticlockwise directions. About horizontal axis no swaying effect is observed.
3 - Question
Which of the following has a tendency to sway engine in alternately in clockwise and anticlockwise directions?
a) Swaying couple
b) Tractive force
c) Hammer blow
d) Hammer couple
View Answer
Answer: a
Explanation: A couple having a swaying effect about a vertical axis, and a tendency to sway the engine alternately in clockwise and anticlockwise directions is known as swaying couple.
4 - Question
At which of the following angles in degrees does the swaying couple attains a maximum value?
a) 135
b) 45
c) 90
d) 60
View Answer
Answer: b
Explanation: The swaying couple is maximum or minimum when (cosθ + sin θ) is maximum or minimum. This results in a relation tanθ=1
hence theta = 45 degrees or 225 degrees.
5 - Question
If the maximum value occurs at 45 degrees then at which of the following angles in degrees will the swaying couple attains its maximum value again?
a) 135
b) 45
c) 225
d) 60
View Answer
Answer: c
Explanation: The swaying couple is maximum or minimum when the relation (cos θ + sin θ) is maximum or minimum. This results in a relation tan θ=1
hence theta = 45 degrees or 225 degrees.
6 - Question
Find the maximum value of swaying couple in newtons from the following data:
m = 100Kg
ω = 300 rpm
radius = 0.6m
c = 2/3
a = 22–√m
a) 6978
b) 7574
c) 6568
d) 7374
View Answer
Answer: a
Explanation: The maximum value of Swaying couple is given by
+a/2–√ (1-c)mω2r
substituting the values we get
F = 6978 N.
7 - Question
Find the minimum value of swaying couple in newtons from the following data:
m = 100Kg
ω = 300 rpm
radius = 0.6m
c = 2/3
a = 22–√m
a) -6978
b) -7574
c) -6568
d)- 7374
View Answer
Answer: a
Explanation: The minimum value of Swaying couple is given by
-(a/2–√)(1-c)mω2r
substituting the values we get
F = -6978 N.
8 - Question
Swaying couple attains a maxima or minima when the crank angle is 45 degrees.
a) True
b) False
View Answer
Answer: a
Explanation: The swaying couple is maximum or minimum when the expression (cos θ +sin θ ) is maximum or minimum, differentiating it with respect to theta gives tan θ = 1
hence maximum/minimum value occurs at 45 or 225 degrees.
9 - Question
Find the variation in swaying couple in newtons from the following data:
m = 100Kg
ω = 300 rpm
radius = 0.6m
c = 2/3
a = 22–√m
a) 13956
b) 17574
c) 16568
d) 17374
View Answer
Answer: a
Explanation: The variation in tractive force is given by
±a/2–√ (1-c)mω2r
substituting the values we get
F = 13956 N.
10 - Question
Find the maximum value of swaying couple in newtons from the following data:
m = 200Kg
ω = 300 rpm
radius = 0.6m
c = 2/3
a = 22–√m
a) 13956
b) 17574
c) 16568
d) 17374
View Answer
Answer: a
Explanation: The maximum value of Swaying couple is given by
+a/2–√(1-c)mω2r
substituting the values we get
F = 13956 N.