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Free download in PDF Design of Machine Elements Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for competitive exams. These short solved questions or quizzes are provided by Gkseries.
21
In design process, which step is followed after defining the problem?
A
Analysis
B
Synthesis
C
Optimization
D
Evaluation
View Answer
22
For brittle materials having static load, factor of safety is given as the ratio of ______
A
endurance strength and design stress
B
design stress and allowable stress
C
working stress and allowable stress
D
ultimate strength and design stress
View Answer
Answer: ultimate strength and design stress
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23
The ratio of endurance strength and allowable stress is used to determine FOS for _____
A
fatigue loading
B
static loading of brittle materials
C
static loading of ductile materials
D
all of the above
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24
Which of the following factors are not considered while selecting values for factor of safety?
A
Cost
B
Failure consequences
C
Degree of uncertainty about loading and material
D
None of the above
View Answer
Answer: None of the above
25
What is the step ratio for R40 series?
A
1.44
B
1.05
C
4.0
D
0.4
View Answer
26
Punching operation is an example of
A
Static load
B
Impact load
C
Fluctuating load
D
None of the above
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27
Torsional Shear Stress is the stress induced when a component is subjected to equal and opposite _______.
A
forces acting in perpendicular direction
B
couples acting in perpendicular direction
C
couples acting in parallel planes
D
forces acting in parallel direction
View Answer
Answer: couples acting in parallel planes
28
What is bearing pressure?
A
Compressive force acting on the contact area between two components having relative motion between them
B
Tensile stress acting on the contact area between two components having relative motion between them
C
Compressive force acting on the contact area between two components having no relative motion between them
D
Compressive stress acting on the contact area between two components having relative motion between them
View Answer
Answer: Compressive stress acting on the contact area between two components having relative motion between them
29
Stress induced on contact area between cotter and socket collar is ______
A
Tensile stress
B
Direct shear stress
C
Crushing stress
D
None of the above
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30
Which among the following is a type of transmission shaft?
A
Spindle shaft
B
Crankshaft
C
Counter shaft
D
All of the above
View Answer
31
Which of the following statements is/are false for an axle?
A
It is used to support rotating machine elements
B
It can transmit torque
C
It is subjected to axial force
D
All of the above
View Answer
Answer: It can transmit torque
32
Which material cannot be used to manufacture shafts?
A
Plain carbon steels
B
Cast iron
C
Both a. and b.
D
None of the above
View Answer
33
Which type of key consists of two square tapered keys placed 90o apart?
A
Tangent key
B
Kennedy key
C
Saddle key
D
Woodruff key
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34
Calculate diameter of shaft using maximum shear stress theory,when equivalent torque of 1000 x 103 N-mm acts on the shaft. 50 Mpa is the allowable shear stress for the shaft
A
100.9 mm
B
319.15 mm
C
46.70 mm
D
Insufficient data
View Answer
35
Notch sensitivity (q) is given by the equation _______
where Kf = fatigue stress concentration factor and Kt = theoretical stress concentration factor
A
( Kf + 1 ) / ( Kt – 1 )
B
( Kf – 1 ) / ( Kt – 1 )
C
( Kf + 1 ) / ( Kt + 1 )
D
( Kf - 1 ) / ( Kt + 1 )
View Answer
Answer: ( Kf – 1 ) / ( Kt – 1 )
36
In S-N diagram, the graph plotted between fatigue strength and number of stress cycles becomes horizontal for which type of materials?
A
Ferrous materials
B
Non-ferrous materials
C
Both a. and b.
D
None of the above
View Answer
Answer: Ferrous materials
37
Which of the following equations is correct for Soderberg Criteria?
A
(σm / Sut) + (σa / Se) = (1 / Nf)
B
(σm / Sut) - (σa / Se) = (1 / Nf)
C
(σm / Syt) + (σa / Se) = (1 / Nf)
D
(σm / Sut) - (σa / Se) = (1 / Nf)
View Answer
Answer: (σm / Syt) + (σa / Se) = (1 / Nf)
38
Calculate overall efficiency of power screw, if the torque applied by the operator is 150 x 103 to move a load of 30 kN through a distance of 10 mm
A
22.36 %
B
37.69 %
C
31.83 %
D
30.23 %
View Answer
39
Determine torque required to overcome collar friction in square threaded screw, if coefficient of friction is 0.12 and axial force of 20 kN is exerted by the screw. Mean radius of friction collar is 20 mm
A
48000 N-mm
B
120 N-mm
C
4800 N-mm
D
12000 N-mm
View Answer
40
Which type of stress is induced in a screw thread ?
A
Torsional shear stress
B
Buckling load
C
Bearing pressure
D
All of the above
View Answer
