Mechanical System Design 4

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Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Mechanical System Design 4

Part 4: List for questions and answers of Mechanical System Design

Q1. What is the weld joint efficiency if pressure vessel is fabricated with single full fillet lap joint?
a) 1.0
b) 0.55
c) 0.65
d) 0.85

Q2. A cylindrical pressure vessel is subjected to operating pressure of 0.55 mpa and corrosion allowance of 2. What is the thickness of pressure vessel shell if its internal diameter is 2000 mm? (σall = 120 N/mm^2 & ηl = 0.75)
a) 6.5 mm
b) 7 mm
c) 9 mm
d) 9.5 mm

Q3. Which equation is used to determine wall thickness for brittle materials?
a) Brinie’s equation
b) Clavier’s equation
c) Lame’s equation
d) All of the above

Q4.Claviro’s equation is applicable to cylinders with _______
a) Close ends
b) Open ends
c) Both a. And b.
d) None of the above

Q5. Due to which effect, compressive residual stress of strain-hardening model is smaller than elastic-perfectly plastic model?
a) Seeback effect
b) Peltier effect
c) Bauschinger effect
d) None of the above

Q6. Why is autofrettage process used in pressure vessels?
a) Increase fatigue lifetime
b) To enhance carrying capacity
c) To introduce compressive residual stress in them
d) All of the above

Q7. Which equation is used to calculate thickness of an alloy steel cylinder with open ends?
a) Clavarino’s equation
b) Birnie’s equation
c) Lame’s equation
d) None of the above

Q8. A vessel is said to be thin if
a) Its wall has less thickness
b) Stresses are uniform over the entire thickness
c) Stresses vary at inner and at outer radius
d) None of the above

Q9. Vessel is said to be thin if
a) D/t =20
b) D/t=10
c) D/t >20
d) D/t >10

Q10. Hoop stress in a thin vessel is
a) Pd/2t
b) Pd/4t
c) Pd/3t
d) None

Q11. Strength of a rivet is
a) Strength in shear
b) Strength in crushing
c) Strength in tension
d) None

Q12. Which stress is the least in a thin shell?
a) Longitudinal stress
b) Hoop stress
c) Radial stress
d) None

Q13. Among the cylindrical and spherical thin vessels of same material, diameter and pressure which has the lesser thickness
a) Cylindrical shell
b) Spherical shell
c) Cylindrical shell with semi spherical heads
d) None

Q14. Radial stress in a thin shell is given by
a) Pd/2t
b) Pd/4t
c) Pd/3t
d) None

Q15. When are the longitudinal and hoop stresses equal in a thin shell?
a) Longitudinal joint η =2 circumferential joint η
b) Longitudinal joint η = circumferential joint η
c) 2 longitudinal joint η = circumferential joint η
d) None

Q16. A thin cylindrical shell under internal pressure can fail by
a) Shear
b) Compression
c) Tension
d) None

Q17. A thin spherical shell under internal pressure will fail under
a) Maximum shear stress
b) Principal compressive stress
c) Principal tensile stress
d) None

Q18. A thin cylindrical under internal pressure can fail along the
a) Longitudinal joint
b) Circumferential joint
c) Longitudinal as well as circumferential joint
d) None

Q19. What is the ratio of hoop stresses in a spherical vs cylindrical shell of same diameter, thickness and under same pressure?
a) 4:1
b) 2:1
c) 1:2
d) 1:4

Q20. Stresses in a thin cylindrical shell under internal pressure is independent of
a) Diameter
b) Thickness
c) Length
d) Diameter and thickness

Part 4: List for questions and answers of Mechanical System Design

Q1. Answer: b

Q2. Answer: c

Q3. Answer: c

Q4. Answer: a

Q5. Answer: c

Q6. Answer: d

Q7. Answer: b

Q8. Answer: b

Q9. Answer: c

Q10. Answer: a

Q11. Answer: d

Q12. Answer: c

Q13. Answer: b

Q14. Answer: d

Q15. Answer: c

Q16. Answer: c

Q17. Answer: c

Q18. Answer: c

Q19. Answer: c

Q20. Answer: c