Machine Design MCQ
SET-3
41. In a hydrodynamic lubricated bearing
- A. there is a thick film of lubricant between the journal and the bearing
- B. there is a thin film of lubricant between the journal and the bearing
- C. there is no lubricant between the journal and the bearing
- D. the lubricant is forced between the journal and the bearing, by external pressure
Answer: A
42. Which of the following statement is correct for gears?
- A. The addendum is less than dedendum
- B. The pitch circle diameter is equal to the product of module and number of teeth
- C. The pitch circle is always greater than the base circle
- D. all of the above
Answer: D
43. A flanged pipe joint will be a leak-proof joint, if the circumferential pitch of the bolts is (where d = Diameter of bolt hole)
- A. less than 20 d
- B. greater than 30 d
- C. between 20 d and 30 d
- D. equal to inside diameter of pipe
Answer: C
44. Stress concentration is caused due to
- A. variations in load acting on a member
- B. variations in properties of materials in a member
- C. abrupt change of cross-section
- D. all of these
Answer: C
45. The resistance to fatigue of a material is measured by
- A. elastic limit
- B. Young’s modulus
- C. ultimate tensile strength
- D. endurance limit
Answer: D
46. The load cup of a screw jack is made separate from the head of the spindle to
- A. enhance the load carrying capacity of the jack
- B. reduce the effort needed for lifting the working load
- C. prevent the rotation of load being lifted
- D. reduce the value of frictional torque
Answer: C
47. Two shafts A and B under pure torsion are of identical length and identical weight and are made of the same material. The shaft A is solid and the shaft B is hollow. We can say that
- A. shaft B is better than shaft A
- B. shaft A is better than shaft B
- C. both the shafts are equally good
Answer: A
48. The centre distance between two meshing involute gears is equal to
Answer: A
49. Which of the following statement is wrong ?
- A. The power transmitted by V-belts is less than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts
- B. The V-belt drive is used with large centre distance
- C. The V-belt may be operated in either direction with tight side of the belt at the top or bottom
- D. The ratio of driving tensions in V-belt drive is more than flat belt drives
Answer: B
50. In a flange coupling, the thickness of flanges is taken as one-half the diameter of shaft.
- A. Agree
- B. Disagree
Answer: A
51. The rolling contact bearings are known as
- A. thick lubricated bearings
- B. plastic bearings
- C. thin lubricated bearings
- D. antifriction bearings
Answer: D
52. The backlash for spur gears depends upon
- A. module
- B. pitch line velocity
- C. tooth profile
- D. both (a) and (b)
53. The size of a gear is usually specified by
- A. pressure angle
- B. pitch circle diameter
- C. circular pitch
- D. diametral pitch
Answer: B
54. The circumferential and longitudinal strains in a cylindrical boiler under internal steam pressure are εc and εl respectively. The change in volume of the boiler cylinder per unit volume will be
Answer: B
55. The bearings of heavy series have capacity __________ over the medium series.
- A. 10 to 20%
- B. 20 to 30%
- C. 30 to 40%
- D. 40 to 50%
Answer: B
56. A steel containing more than 0.8% carbon is known as eutectoid steel.
- A. Yes
- B. No
Answer: B
57. In leaf springs, the longest leaf is known as
- A. lower leaf
- B. master leaf
- C. upper leaf
- D. none of these
Answer: B
58. The taper on cotter varies from
- A. 1 in l5 to 1 in 10
- B. 1 in 24 to 1 in 20
- C. 1 in 32 to 1 in 24
- D. 1 in 48 to 1 in 24
Answer: D
59. Which of the following screw thread is used for power transmission in one direction only.
- A. Acme threads
- B. Square threads
- C. Buttress threads
- D. Multiple threads
Answer: C
60. When the bearing is subjected to large fluctuations of load and heavy impacts, the bearing characteristic number should be __________ the bearing modulus.
- A. 5 times
- B. 10 times
- C. 15 times
- D. 20 times
Answer: C