Machine design objective questions with answers part1

Q1. Yield point in fatigue loading as compared to static loading is
(A) same
(B) higher
(C) lower
(D) depends on other factors

Q2. Residual stress in materials
(A) acts when external load is applied
(B) is independent of external loads
(C) is always harmful
(D) is always beneficial

Q3. building up of worn and uridersized parts, subjected to repeated loads by electroplating is
(A) best method
(B) extremely hazardous
(C) has no effect as regards fatigue strength
(D) cheapest method

Q4. In nitrated parts, the origins of the fatigue cracks will occur at
(A) surface
(B) just below the surface
(C) within the core
(D) none of these

Q5. Which process will increase the fatigue duration of parts ?
(A) finishing and polishing
(B) shot-peening
(C) decarburisation
(D) electroplating

Q6. Which is correct statement ?
(A) a member made of steel will generally be more rigid than a member of equal load-carrying ability made of cast iron
(B) a member made of cast iron will generally be. more rigid than a member of equal load carrying ability made of steel
(C) both will be equally rigid
(D) which one is rigid will depend on several other factors

Q7. Resistance to fatigue of a material is measured by
(A) Young’s modulus
(B) coefficient of elasticity
(C) ultimate tensile strength
(D) endurance limit

Q8. In most machine members, the damping capacity of the material should be
(A) low
(B) zero
(C) high
(D) All are correct

Q9. The ratio of endurance limit in shear to the endurance limit in flexure is
(A) 0.35
(B) 0.4
(C) 0.5
(D) 0.55

Q10. For steel, the ultimate strength in shear as compared to ultimate strength in tension is
(A) same
(B) 01/02/20
(C) 01/04/20
(D) 02/03/20

Q11. The endurance limit in shear of carbon steel can be obtained by multiplying the endurance limit in flexure by a factor of
(A) 0.25
(B) 0.55
(C) 0.65
(D) 0.75

Q12. At low temperatures (say 75°C) the notched-bar impact value of steel
(A) increases markedly
(B) decreases markedly
(C) remains same
(D) depends on heat treatment carried out

Q13. The crest diameter of a screw thread is same as
(A) major diameter
(B) minor diameter
(C) pitch diameter
(D) core diameter

Q14. Maximum principal stress theory is applicable for
(A) ductile materials
(B) brittle materials
(C) elastic materials
(D) all of the above

Q15. The following type of nut is used with alien bolt
(A) alien nut
(B) hexagonal nut
(C) slotted nut
(D) any one of these

Q16. A stud
(A) has a head on one end and a nut fitted to the other
(B) has head at one end and other end fits into a tapped hole in the other part to be joined
(C) has both the ends threaded
(D) has pointed threads

Q17. Shear stress theory is applicable for
(A) ductile fnaterials
(B) brittle materials
(C) elastic materials
(D) all of the above

Q18. For applications involving high stresses in one direction only the following type of thread would be best suited
(A) ISO metric thread
(B) acme thread
(C) square thread
(D) buttress thread

Q19. The included angle in unified of American National threads is
(A) 60°
(B) 55°
(C) 17°
(D) 39°

Q20. The function of a washer is to
(A) provide cushioning effect
(B) provide bearing area
(C) absorb shocks and vibrations
(D) provide smooth surface in place of rough surface