1) In design process, which step is followed after defining the problem?
a. Analysis
b. Synthesis
c. Optimization
d. Evaluation
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2) 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
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3) 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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4) 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
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5) What is the step ratio for R40 series?
a. 1.44
b. 1.05
c. 4.0
d. 0.4
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6) Punching operation is an example of
a. Static load
b. Impact load
c. Fluctuating load
d. None of the above
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7) 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
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8) 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
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Answer
Explanation
Related Ques
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ANSWER: Compressive stress acting on the contact area between two components having relative motion between them
Explanation:
No explanation is available for this question!
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9) Compressive stress acting on the contact area between two components having no relative motion between them is known as crushing stress
a. True
b. False
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10) 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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11) Which among the following is a type of transmission shaft?
a. Spindle shaft
b. Crankshaft
c. Counter shaft
d. All of the above
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12) 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
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13) 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
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14) 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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15) 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
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16) 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 )
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17) Which of the following conditions is true for repeated stress?
1. σm = 0
2. σm = σmax / 2
3. σm = σa
4. σmin = 0
5. σmin = – σmax
6. σa = σmax / 2
where σm = mean stress and σa = stress amplitude
a. condition 2 and 3
b. condition 1, 3 and 5
c. condition 2, 4, and 6
d. condition 3,4, 5 and 6
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18) 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
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19) Match the following Group 1 items with Group 2 items and select the correct option
1. Size factor ----------------------------------------- A. Kc
2. Load factor ---------------------------------------- B. Kg
3. Temperature factor ------------------------------- C. Kb
4. Reliability factor --------------------------------- D. Kd
a. 1 – B, 2 – A, 3 – D, 4 – C
b. 1 – C, 2 – A, 3 – D, 4 – B
c. 1 – D, 2 – B, 3 – A, 4 – C
d. 1 – D, 2 – C, 3 – A, 4 – B
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20) 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)
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21) Calculate lead angle of a thread which has mean diameter of 45 mm and lead of 10 mm
a. 8.5o
b. 4.04o
c. 3.02o
d. None of the above
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22) 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 %
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23) 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
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24) 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
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25) A single start square threaded power screw supports load of 30 kN which has outer diameter of 30 mm and a pitch of 8 mm. Maximum shear stress of 30 N/mm2 is induced in a screw body. Determine number of screw threads considering direct shear stress.
a. 3 threads
b. 2 threads
c. 4 threads
d. None of the above
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26) Which among the following statements is/are true?
1. Fracture of bolts occurs due to uneven distribution of impact energy
2. Castle nut is a locking device
3. Fine threads are stronger than coarse threads
4. Coarse threads apply more resistance when loosened
a. Statement 2 and Statement 3
b. Statement 1 and Statement 2
c. Statement 3 and Statement 4
d. All of the above
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27) Which of the following threads have greater pitch and lead angle for a given nominal diameter when compared with each other?
a. Coarse threads
b. Fine threads
c. Both a. and b.
d. None of the above
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28) Which type of screw fasteners are threaded at both the ends?
a. Through bolt
b. Tap bolt
c. Studs
d. All of the above
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29) What does the designation M 16 x 2 indicate?
a. I.S.O. Metric fine thread
b. I.S.O. Metric coarse thread
c. B.S.F. Metric coarse thread
d. B.S.F Metric fine thread
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30) Which type of screw fasteners are threaded through out its length?
a. Cap screws
b. Set screws
c. Studs
d. Tap bolt
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31) Which type of joint is used if plate thickness is less than 5 mm?
a. Single V butt weld
b. Single U butt weld
c. Square butt weld
d. Double U butt weld
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32) Which welding symbol is shown below?
a. Lap joint
b. Single V butt joint
c. Double fillet weld
d. Single fillet weld
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33) Calculate strength of the welded joint shown below, when 70 MPa is the allowable shear stress for the weld material.
a. 54.44 x 103 N
b. 77 x 103 N
c. 50 x 103 N
d. None of the above
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34) Calculate weld throat thickness for the parallel fillet weld shown below, if allowable shear stress is 80 MPa and tensile load of 300 kN is acting on it.
a. 2.6 mm
b. 9.56 mm
c. 9.86 mm
d. 8.36 mm
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35) Calculate weld size if weld throat thickness for the fillet weld is 8.2 mm
a. 10 mm
b. 14.20 mm
c. 16.4 mm
d. 12 mm
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36) Free length for helical compression springs having square ends is given as ________.
a. pn + 2d
b. pn + 3d
c. 2(p + d)
d. pn + 4d
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37) What is the Wahl's factor if spring index is 6?
a. 1.477
b. 0.995
c. 1.252
d. None of the above
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38) Why are mechanical springs used?
a. To apply force
b. To store energy
c. To measure force
d. All of the above
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39) Which of the following statements is/are true?
1. In volute springs, number of active coils gradually decreases as load increases
2. Stiffness of spring decreases as number of coils decreases in conical springs
3. Torsion springs are generally spiral
4. Helical torsion springs are used in automobile starters
a. Statements 1 and 3
b. Statements 2, 3 and 4
c. Statements 1, 3 and 4
d. All of the above
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40) In which condition the axial distance between two adjacent coils is called as pitch?
a. Compressed condition
b. Uncompressed condition
c. Both a. and b.
d. None of the above
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