SECTION-5

**MACHINE DESIGN MCQ**

**Q41. The efficiency of a square threaded screw will be maximum, if the helix angle is equal to**

(a)π/4 + φ/ 2

(b)π/4– φ

(c) π /4− φ/ 2

(d) π/4+ φ

where φ = Angle of friction.

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**Q42. Two plates of thickness 5 mm are joined by a double riveted double cover butt joints. The diameter of rivets is 7 mm and pitch = 28 mm. The permissible tensile, shear and crushing stresses are 120 N/mm2, 100 N/mm**^{2} and 150 N/mm^{2} respectively. The pull required to tear off the plate across the row of rivets per pitch length is equal to

^{2}and 150 N/mm

^{2}respectively. The pull required to tear off the plate across the row of rivets per pitch length is equal to

(a) 15400 N

(b) 16800 N

(c) 12600 N

(d) 9800 N.

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**Q43. Two plates of thickness 5 mm are joined by a double riveted double cover butt joints. The diameter of rivets is 7 mm and pitch = 28 mm. The permissible tensile, shear and crushing stresses are 120 N/mm2, 100 N/mm**^{2} and 150 N/mm^{2} respectively, the theoretical pull required to shear off the rivets per pitch length is equal to

^{2}and 150 N/mm

^{2}respectively, the theoretical pull required to shear off the rivets per pitch length is equal to

(a) 15400 N

(b) 16800 N

(c) 12600 N

(d) 9800 N.

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**Q44. Two plates of thickness 5 mm are joined by a double riveted double cover butt joints. The diameter of rivets is 7 mm and pitch = 28 mm. The permissible tensile, shear and crushing stresses are 120 N/mm2, 100 N/mm**^{2} and 150 N/mm^{2} respectively, the pull required to crush the rivet per pitch length is equal to

^{2}and 150 N/mm

^{2}respectively, the pull required to crush the rivet per pitch length is equal to

(a) 15400 N

(b) 16800 N

(c) 12600 N

(d) 9800 N.

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**Q45. Two plates of thickness 5 mm are joined by a double riveted double cover butt joints. The diameter of rivets is 7 mm and pitch = 28 mm. The permissible tensile, shear and crushing stresses are 120 N/mm2, 100 N/mm**^{2} and 150 N/mm^{2} respectively, the strength of the joint is equal to

^{2}and 150 N/mm

^{2}respectively, the strength of the joint is equal to

(a) 15400 N

(b) 16800 N

(c) 12600 N

(d) 9800 N.

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**Q46. Two plates of thickness 5 mm are joined by a double riveted double cover butt joints. The diameter of rivets is 7 mm and pitch = 28 mm. The permissible tensile, shear and crushing stresses are 120 N/mm2, 100 N/mm**^{2} and 150 N/mm^{2} respectively, the efficiency of the joint is equal to

^{2}and 150 N/mm

^{2}respectively, the efficiency of the joint is equal to

(a) 80%

(b) 70%

(c) 58.33%

(d) 50%.

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**Q47. The rotation of a bolt, while screwing a nut on or off the bolt, is prevented by providing on the bolt**

(a) a square neck

(b) a pip

(c) a snug

(d) any one of the above

(e) none of the above.

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**Q48. The locking arrangement for the nut is done by**

(a) a split pin

(b) a slotted nut

(c) a castle nut

(d) a sawn nut

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**Q49. If the nut is made of a weaker material than the bolt, then the height of the nut should be**

(a) equal to nominal diameter of the bolt

(b) less than the nominal diameter of the bolt

(c) more than the nominal diameter of the bolt

(d) none of the above.

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**Q50. Choose the wrong statement**

(a) For leak-proof joint, the circumferential pitch of the studs should be between 20 \[ \sqrt{d}_{1}\] and 30 \[ \sqrt{d}_{1}\]where d1 is thediameter of stud hole in mm.

(b) The effective height of the nut is made equal to the nominal diameter of the bolt, when a nut and bolt are made of mild steel.

(c) If an axial hole is drilled through the head of a bolt upto threaded portion such that the area of the shank becomes equal to the root area of the thread, the bolt of uniform strength is obtained.

(d) Turn buckle has left hand threads on both ends.

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**Read More Sections of Machine Design**

Each section contains maximum 80 Questions. To practice more questions visit other sections.

**Machine Design MCQ – Section-1**

**Machine Design MCQ – Section-2**

**Machine Design MCQ – Section-3**

**Machine Design MCQ – Section-4**

**Machine Design MCQ – Section-5**

**Machine Design MCQ – Section-6**

**Machine Design MCQ – Section-7**