SECTION-4

##### MACHINE DESIGN MCQ

**Q31. For equal number of rivets is more than one row for lap joint or butt joint, the pitch of the rivets should not be less than**

(a)2/d

(b) d

(c) 1.5 d

(d) 2 d.

where d = Diameter of rivet hole.

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**Q32. The pitch of the rivets is calculated by assuming the efficiency of the joint given by**

(a) η =p/p -d

(b) η =p/p +d

(c) η =p − d/p

(d) η =p+2/p +2d

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**Q33. According to I.B.R., the maximum value of the pitch of rivets for a longitudinal joint of a boiler is given by**

(a) 4.128 cm

(b) t + 4.128 cm

(c) C × t + 4.128 cm

(d)C×t/4.128

where t = Thickness of the shell plate in cm, and C = Constant.

#####
**Q34. In case of parallel fillet welded joint, the shear stress is given by**

(a)0.707F/h ×l

(b)1.414 F/h ×l

(c)0.5 F/h ×l

(d)0.75 F/h ×l

#####
**Q35. The size of the weld, in case of a transverse fillet welded joint, is equal to**

(a) one-third of the throat of weld

(b) half of the throat of weld

(c) 1.414 times the throat of weld

(d) the throat of the weld.

#####
**Q36. A key is a piece of mild steel inserted between the shaft and hub to connect them together.**

(a) prevents relative motion between the shaft and hub

(b) is always inserted parallel to the axis of the shaft

(c) is subjected to crashing and shearing stresses

(d) has all the above function.

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**Q37. A sunk key is a key**

(a) made from a cylindrical disc having segmental cross-section

(b) which fits half in the key way of the hub and half in the key way of shaft

(c) which is flat on the shaft and fits in a key way in the hub

(d) none of the above.

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**Q38. Choose the correct statement**

(a) Feather keys are generally tight in the shaft and loose in the hub.

(b) The distribution of the stresses along the length of the key fitted in a shaft is of exponential shape, being more at the torque input end.

(c) In designing a key, the distribution of the stresses along the length of key is assumed uniform throughout.

(d) All of the above.

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**Q39. If the permissible crushing stress for the key material is double the permissible shearing stress, then a sunk key will be equally strong in shearing and crushing if the key is a**

(a) rectangular key with width equal to twice the thickness

(b) rectangular key with width equal to half the thickness

(c) rectangular key with width equal to one-fourth the thickness

(d) square key.

#####
**Q40. The hub length of the flange coupling should not be less than**

(a) 3D

(b) 2D

(c) 1.5D

(d) D

where D = Diameter of solid shaft.

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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**