Design of Machine Elements - 1 Test Set - 2

1)   Match the following Group 1 items (Preferred series) and Group 2 items ( Step ratios) and select the correct option

1. R5 ------------------------------------------------ A. 1.12
2. R20 ----------------------------------------------- B. 1.26
3. R80 ----------------------------------------------- C. 1.58
4. R10 ----------------------------------------------- D. 1.03


a. 1 – D, 2 – C, 3 – A, 4 – B
b. 1 – B, 2 – D, 3 – C, 4 – A
c. 1 – A, 2 – C, 3 – D, 4 – B
d. 1 – C, 2 – A, 3 – D, 4 – B
Answer  Explanation  Related Ques

ANSWER: 1 – C, 2 – A, 3 – D, 4 – B

Explanation:
No explanation is available for this question!


2)   The application factor depends on ______

a. prime mover
b. hours of operation per day
c. machine driven
d. all of the above
Answer  Explanation  Related Ques

ANSWER: all of the above

Explanation:
No explanation is available for this question!


3)   What is meant by application factor?

a. Ratio of maximum torque and average torque
b. Ratio of maximum load and average load
c. Both a. and b.
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Both a. and b.

Explanation:
No explanation is available for this question!


4)   What is meant by Aesthetics?

a. Interaction between man machine working environment
b. Appearance of the product
c. Both a. and b.
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Interaction between man machine working environment

Explanation:
No explanation is available for this question!


5)   Series of numbers offered by arithmetic progression are called as preferred series

a. True
b. False


Answer  Explanation  Related Ques

ANSWER: False

Explanation:
No explanation is available for this question!


6)   Which among the following is a knuckle joint?

a. Tension link in bridge structure
b. Foundation bolt
c. Both a. and b.
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Tension link in bridge structure

Explanation:
No explanation is available for this question!


7)   What are assumptions made during stress analysis of curved beams?

a. The material is nonisotropic
b. The material is non homogeneous
c. The material obeys hooke's law
d. All of the above
Answer  Explanation  Related Ques

ANSWER: The material obeys hooke's law

Explanation:
No explanation is available for this question!


8)   Which of the following statements is/are true?

a. The bending stress distribution in bending of straight beams is nonlinear
b. The bending stress distribution in bending of curved beams is hyperbolic
c. The neutral axis coincides with geometrical axis during bending of curved beams
d. All of the above
Answer  Explanation  Related Ques

ANSWER: The bending stress distribution in bending of curved beams is hyperbolic

Explanation:
No explanation is available for this question!


9)   Which factors are responsible for the failure of a component due to buckling?

a. Yielding
b. Plastic deformation
c. Elastic instability
d. All of the above
Answer  Explanation  Related Ques

ANSWER: Elastic instability

Explanation:
No explanation is available for this question!


10)   The formula (π2 E A) / ( Le / K)2 is devised to determine buckling load by

where E = modulus of elasticity, Le = equivalent length, K = radius of gyration


a. Rankine
b. Euler
c. J. B. Johnson
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Euler

Explanation:
No explanation is available for this question!


11)   Which formula is used if slenderness ratio Le / K < X, where X = √ ( 2π 2 E / Syc )?

a. Euler's formula
b. J. B. Johnson formula
c. Rankine formula
d. None of the above
Answer  Explanation  Related Ques

ANSWER: J. B. Johnson formula

Explanation:
No explanation is available for this question!


12)   Calculate diameter of shaft using maximum principle stress theory, when equivalent bending moment of 900 x 103 N-mm acts on the shaft when maximum tensile stress does not exceed 50 N/mm2 and equivalent torque of 700 N-m acts on it.

a. 56.80 mm
b. 52.24 mm
c. 50 mm
d. None of the above
Answer  Explanation  Related Ques

ANSWER: 56.80 mm

Explanation:
No explanation is available for this question!


13)   A shaft transmits power of 30 kW. According to maximum principle stress theory and shear theory diameter of shaft is 70 mm and 73 mm respectively. Tensile stress acting on the shaft is 50 Mpa. What will be the shaft diameter to transmit power?

a. 65 mm
b. 70 mm
c. 73 mm
d. Insufficient data
Answer  Explanation  Related Ques

ANSWER: 73 mm

Explanation:
No explanation is available for this question!


14)   According to A.S.M.E code what is the allowable shear stress for a shaft without keyway effect, which has ultimate tensile strength and yield strength of 300 N/mm2 and 150 N/mm2 respectively.

a. 45 N/mm2
b. 54 N/mm2
c. 40.5 N/mm2
d. None of the above
Answer  Explanation  Related Ques

ANSWER: 45 N/mm2

Explanation:
No explanation is available for this question!


15)   Universal coupling is a type of ____

a. Flexible coupling
b. Rigid coupling
c. Both a. and b.
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Flexible coupling

Explanation:
No explanation is available for this question!


16)   Why are rigid couplings used?

a. To connect diesel engine and generator
b. To connect eccentric shafts
c. To connect electric motor to pump
d. None of the above
Answer  Explanation  Related Ques

ANSWER: To connect electric motor to pump

Explanation:
No explanation is available for this question!


17)   Calculate fatigue stress concentration factor, when theoretical stress concentration factor is 1.62 and notch sensitivity is equal to 0.9

a. 1.558
b. 3.358
c. 1.162
d. None of the above
Answer  Explanation  Related Ques

ANSWER: 1.558

Explanation:
No explanation is available for this question!


18)   Line joining Syt (yield strength of the material) on mean stress axis and Se (endurance limit of the component) on stress amplitude axis is called as _____

a. Goodman line
b. Soderberg line
c. Gerber line
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Soderberg line

Explanation:
No explanation is available for this question!


19)   According to Modified Goodman Diagram for fluctuating torsional shear stress, which line defines fatigue failure?

Modified-Goodman-Diagram-1.png
a. Line joining point Sys on mean stress and stress amplitude
b. Horizontal line QR at point Ses on stress amplitude
c. Polyline STRQ defines fatigue failure
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Horizontal line QR at point Ses on stress amplitude

Explanation:
No explanation is available for this question!


20)   In diagram shown below, what does angle θ correspond to?

Modified-Goodman-Diagram-2.png
a. It corresponds to actual stress point
b. It corresponds to point of intersection of fatigue failure line and static failure line
c. It corresponds to actual strain point
d. None of the above
Answer  Explanation  Related Ques

ANSWER: It corresponds to actual stress point

Explanation:
No explanation is available for this question!


21)   To predict failure in design components which failure criteria is not assumed, when mean stress and stress amplitude are nonzero?

a. Goodman criterion
b. Soderberg criteria
c. Gerber criteria
d. None of the above
Answer  Explanation  Related Ques

ANSWER: None of the above

Explanation:
No explanation is available for this question!


22)   A triple start square threaded power screw has torsional shear stress and direct compressive stress of 5 N/mm2 and 7 N/mm2. Calculate maximum shear stress induced in a screw body.

a. 7.4 N/mm2
b. 3.5 N/mm2
c. 6.10 N/mm2
d. 5 N/mm2
Answer  Explanation  Related Ques

ANSWER: 6.10 N/mm2

Explanation:
No explanation is available for this question!


23)   In power screws, if friction angle Φ is less than lead angle λ, then the screw undergoes _______

a. over hauling
b. self locking
c. both a. and b.
d. none of the above
Answer  Explanation  Related Ques

ANSWER: over hauling

Explanation:
No explanation is available for this question!


24)   The efficiency of power screw can be improved if ______

a. the rolling friction is replaced by sliding friction in the screw threads
b. the sliding friction is replaced by rolling friction in the screw threads
c. both a. and b.
d. none of the above
Answer  Explanation  Related Ques

ANSWER: the sliding friction is replaced by rolling friction in the screw threads

Explanation:
No explanation is available for this question!


25)   Calculate torque required to overcome thread friction if axial load of 8 kN acts on a power screw having double start square threads of 30 mm mean diameter. Friction angle and lead angle are 7o and 9o respectively

a. 68.81 N-m
b. 41.90 N-m
c. 34.40 N-m
d. Insufficient data
Answer  Explanation  Related Ques

ANSWER: 34.40 N-m

Explanation:
No explanation is available for this question!


26)   Which type of stress is induced in a screw body?

a. Bearing pressure
b. Direct shear stress
c. Torsional shear stress
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Torsional shear stress

Explanation:
No explanation is available for this question!


27)   What is the approximate nominal diameter for coarse threads?

a. d = 1.136 dc
b. d = 1.59 dc
c. d = 1.19 dc
d. d = 0.5 dc
Answer  Explanation  Related Ques

ANSWER: d = 1.19 dc

Explanation:
No explanation is available for this question!


28)   Drilling axial hole is a method used to achieve ______

a. uniform strength
b. uniform stress
c. uniform toughness
d. all of the above
Answer  Explanation  Related Ques

ANSWER: uniform strength

Explanation:
No explanation is available for this question!


29)   Threads used in screw fasteners are ______

a. having high strength
b. having low efficiency
c. single start type
d. all of the above
Answer  Explanation  Related Ques

ANSWER: all of the above

Explanation:
No explanation is available for this question!


30)   Which among the following is the condition to avoid separation of connected members?

a. Force acting on the connected members should be negative
b. Force acting on the connected members should be positive
c. Force acting on the connected members should be neither positive nor negative
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Force acting on the connected members should be negative

Explanation:
No explanation is available for this question!


31)   When a coupler nut is subjected to crushing stress, crushing failure can be avoided if _____

a. crushing stress induced is more than permissible crushing stress in the nut
b. permissible crushing stress is more than crushing stress induced in the threads
c. crushing stress induced is equal to permissible crushing stress
d. all of the above
Answer  Explanation  Related Ques

ANSWER: permissible crushing stress is more than crushing stress induced in the threads

Explanation:
No explanation is available for this question!


32)   Axially loaded unsymmetrical welded joint is shown below, if total length of the weld is (la + lb) then length of weld la is given as

Unsymmetrical-Welded-body.png
a. (b / (a+b)) x l
b. (a / (a+b)) x l
c. (a / (a -b)) x l
d. (b / (a-b)) x l
Answer  Explanation  Related Ques

ANSWER: (b / (a+b)) x l

Explanation:
No explanation is available for this question!


33)   In the diagram shown below la = lb = 100 mm, what is the load carrying capacity if weld size is 15 mm and shear stress for the weld is 100 MPa

Numerical-Load-Carrying-Capacity.png
a. 200 kN
b. 310 kN
c. 212.13 kN
d. 121.13 kN
Answer  Explanation  Related Ques

ANSWER: 212.13 kN

Explanation:
No explanation is available for this question!


34)   If welds are designed with in-plane eccentric load, then eccentric load can be replaced by _______.

a. parallel force
b. twisting moment
c. both a. and b.
d. none of the above
Answer  Explanation  Related Ques

ANSWER: both a. and b.

Explanation:
No explanation is available for this question!


35)   Which of the following statements is/are false?

1. Under fatigue load, casted structures are stronger than welded structures
2. Welding cannot produce complicated structures
3. Welding can join dissimilar materials
4. Rivetted joints produce light weight constructions as compared to welded joints


a. Statement 1 and Statement 3
b. Statement 1, 2 and Statement 4
c. Statement 1, 2 and Statement 3
d. All the above statements are false
Answer  Explanation  Related Ques

ANSWER: Statement 1, 2 and Statement 4

Explanation:
No explanation is available for this question!


36)   Which formula is used to calculate shear strength of butt weld?

a. P = τ h l
b. P = τ h l2
c. P = τ h2 l
d. None of the above
Answer  Explanation  Related Ques

ANSWER: P = τ h l

Explanation:
No explanation is available for this question!


37)   Solid length for helical compression springs having square and ground ends is given as _________.

a. (n + 2)d
b. (n + 3)d
c. (n + 1)d
d. None of the above
Answer  Explanation  Related Ques

ANSWER: (n + 2)d

Explanation:
No explanation is available for this question!


38)   Which type of springs have only active coils?

a. Helical compression springs
b. Helical tension springs
c. Both a. and b.
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Helical tension springs

Explanation:
No explanation is available for this question!


39)   The shear stress concentration factor (Ks) in mechanical springs is given as _____

a. (1 + 0.5 / C)
b. 0.615 / C
c. (1 + 0.615 / C)
d. [(4C – 1) / (4C + 1)] + [0.615 / C]
Answer  Explanation  Related Ques

ANSWER: (1 + 0.5 / C)

Explanation:
No explanation is available for this question!


40)   Which factor is used to consider the effects of direct shear stress and torsional shear stress when curvature effect stress is not considered?

a. Shear stress concentration factor
b. Wahl shear stress concentration factor
c. Both a. and b.
d. None of the above
Answer  Explanation  Related Ques

ANSWER: Shear stress concentration factor

Explanation:
No explanation is available for this question!


41)   Determine number of coils in a helical compression spring, if modulus of rigidity is 80 Gpa and spring stiffness is 50 N/ mm. Assume wire diameter and spring index as 8 mm and 5 respectively

a. 11.8 turns
b. 12.8 turns
c. 13.3 turns
d. None of the above
Answer  Explanation  Related Ques

ANSWER: 12.8 turns

Explanation:
No explanation is available for this question!