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

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

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

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?
b) Directly proportional
c) Linear
d) Inversely proportional

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

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?
d) m/s2

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

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

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