Engineering Questions with Answers - Multiple Choice Questions
Machine Dynamics MCQ – Analytical Synthesis for Slider Crank Mechanism
1 - Question
If the crank rotation angle varies from 45 degrees to 135 degrees, Using three precision points with chebyshev’s spacing, synthesize a slider crank mechanism where where displacement of slider is square of the crank rotation. From the above information calculate ‘a’ in mm.
a) 48.2
b) 58.2
c) 45.6
d) 42.2
View Answer
Answer: a
Explanation: From the above data θs=45° and θf=135°, assuming starting displacement and final displacement of slider as 100mm and 30mm respectively,
We calculate k1 = 96.4mm
k1 = 2a
Therefore a = 48.2mm.
2 - Question
If the crank rotation angle varies from 45 degrees to 135 degrees, Using three precision points with chebyshev’s spacing, synthesize a slider crank mechanism where where displacement of slider is square of the crank rotation. From the above information calculate ‘c’ in mm.
a) 148.2
b) 158.2
c) 135.7
d) 120.2
View Answer
Answer: c
Explanation: From the above data θs=45° and θf=135°, assuming starting displacement and final displacement of slider as 100mm and 30mm respectively,
We calculate k1 = 96.4mm
k1 = 2a
Therefore a = 48.2mm
Now k2 = 2.a.c = 13084
Therefore c = 135.7mm.
3 - Question
If the crank rotation angle varies from 45 degrees to 135 degrees, Using three precision points with chebyshev’s spacing, synthesize a slider crank mechanism where where displacement of slider is square of the crank rotation. From the above information calculate ‘b’ in mm.
a) 148.2
b) 158.2
c) 135.7
d) 120.2
View Answer
Answer: d
Explanation: From the above data θs=45° and θf=135°, assuming starting displacement and final displacement of slider as 100mm and 30mm respectively,
We calculate k1 = 96.4mm
k1 = 2a
Therefore a = 48.2mm
Now k2 = 2.a.c = 13084
Therefore c = 135.7mm
Now b2 = a2 + c2 – k3
Therefore b = 120.2mm.
4 - Question
What is the relation between displacement of slider and crank angle over an interval?
a) Quadratic
b) Directly proportional
c) Linear
d) Inversely proportional
View Answer
Answer: c
Explanation: The displacement of the slider depends on the crank angle in a linear mathematical relation. It also depends on the starting crank angle and starting point.
5 - Question
Which of the following is true regarding synthesis of mechanisms?
a) It determines the dimensions of the link
b) It determines the input and output angles of the links
c) It determines velocity of link
d) It determines acceleration of link
View Answer
Answer: a
Explanation: For computer aided synthesis of mechanism, determination of the dimensions of the given link is the main objective.
6 - Question
What is the unit of constant of proportionality C used in the relation between displacement of slider and crank angle?
a) m/rad
b) m/s-rad
c) m-s/rad
d) m/s2
View Answer
Answer: a
Explanation: The displacement of the slider is proportional to the crank angle hence a proportionality constant C is introduced; this has the units metre/radians. m/rad.
7 - Question
Synthesis of mechanism is used to determine the acceleration of the link.
a) True
b) False
View Answer
Answer: b
Explanation: Synthesis of mechanism is used to determine the dimensions of the link, acceleration of the link can be calculated by using methods of klein’s constructions.
8 - Question
Constant of proportionality is always positive.
a) True
b) False
View Answer
Answer: b
Explanation: The constant of proportionality used in the relation between slider displacement and the crank angle can take both positive and negative values.
9 - Question
From the given data calculate the constant of proportionality.
s = 10mm, Ss = 5mm θ=50 degrees and θs = 45 degrees.
a) 1
b) -1
c) 1/2
d) -1/2
View Answer
Answer: a
Explanation: We know that constant of proportionality is related by:
s – Ss = C(θ – θs)
substituting the values we get
C = 1.