Machine Design MCQ Solved Paper for NEET

1. In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
A. The effect of curvature of the cylinder wall is neglected
B. The tensile stresses are uniformly distributed over the section of the walls
C. The effect of the restraining action of the heads at the end of the pressure vessel is neglected
D. All of the above
Answer : D

2. The edges of a boiler plate are bevelled to an angle of
A. 30°
B. 45°
C. 60°
D. 80°
Answer : D

3. Resistance to fatigue of a material is measured by
A. Young's modulus
B. Coefficient of elasticity
C. Elastic limit
D. Endurance limit
Answer : D

4. A key way lowers
A. The strength of the shaft
B. The rigidity of the shaft
C. Both the strength and rigidity of the shaft
D. The ductility of the shaft
Answer : C

5. The width of the pulley should be __________ width of the belt.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : C

6. In block brakes, the ratio of shoe width to wheel diameter is taken between
A. 0.1 and 0.25
B. 0.25 and 0.50
C. 0.50 and 0.75
D. 0.75 and 1
Answer : B

7. The included angle between the sides of V-belt is
A. 40°
B. 45°
C. 38°
D. 60°
Answer : A

8. The application of third type levers is found in
A. Handle of a hand pump
B. Hand wheel of a punching press
C. Lever of a loaded safety valve
D. A pair of tongs
Answer : D

9. Ball bearing type screws are found in following application
A. Screw jack
B. Aeroplane engines
C. Crane
D. Steering mechanism
Answer : D

10. Auto frettage is the method of
A. Joining thick cylinders
B. Calculating stresses in thick cylinders
C. Pre-stressing thick cylinders
D. Increasing the life of thick cylinders
Answer : C

11. In skew bevel gearing, the axes of shafts are
A. Intersecting and the teeth are curved
B. Non-intersecting and nonparallel and the teeth are curved
C. Non-intersecting and non-parallel and the teeth are straight
D. None of the above
Answer : C

12. The expansion joint is mostly used for pipes which carry steam at __________ pressures.
A. Low
B. High
C. Medium
D. None of these
Answer : B

13. Factor of safety for fatigue loading is the ratio of
A. Elastic limit to the working stress
B. Elastic limit to the yield point
C. Endurance limit to the working stress
D. Young's modulus to the ultimate tensile strength
Answer : C

14. The minimum number of teeth on the pinion which will mesh with any gear without interference for 20° full depth involute teeth will be
A. 12
B. 14
C. 18
D. 24
Answer : C

15. Which of the following formula is used in designing a connecting rod?
A. Euler's formula
B. Rankine's formula
C. Johnson's straight line formula
D. Johnson's parabolic formula
Answer : B

16. For a shoe brake, the equivalent coefficient of friction is equal to (where ? = Actual coefficient of friction, and ? = Semi-block angle)
A. 2? sin?/(? + sin?)
B. ? sin?/(2? + sin 2?)
C. 4? sin?/(? + sin?)
D. 4? sin?/(2? + sin 2?)
Answer : D

17. In second type of levers,
A. Load is in between the fulcrum and effort
B. Effort is in between the fulcrum and load
C. Fulcrum is in between the load and effort
D. None of these
Answer : A

18. In replacing the V-belts, a complete set of new belts is used instead of replacing a single damaged belt because
A. Belts are available in sets
B. Only one belt cannot be fitted with other used belts
C. The new belt will carry more than its share and result in short life
D. New and old belts will cause vibrations
Answer : C

19. The piston rod of a steam engine is usually connected to the crosshead by means of
A. Bolted joint
B. Knuckle joint
C. Cotter joint
D. Universal joint
Answer : C

20. The plasticity is the property of a material which enables it to
A. Regain its original shape after deformation when the external forces are removed
B. Draw into wires by the application of a tensile force
C. Resist fracture due to high impact loads
D. Retain deformation produced under load permanently
Answer : D

21. Spring stiffness is
A. Ratio of coil diameter to wire diameter
B. Load required to produce unit deflection
C. Its capability of storing energy
D. Its ability to absorb shocks
Answer : B

22. When bevel gears connect two shafts whose axes intersect at an angle greater than a right angle and one of the bevel gears has a pitch angle of 90°, then they are known as
A. Angular bevel gears
B. Mitre gears
C. Internal bevel gears
D. Crown bevel gears
Answer : D

23. The resultant axial load on a bolt depends upon
A. External load applied
B. Initial tension due to tightening of the bolt
C. Relative elastic yielding of the bolt and the connected members
D. All of the above
Answer : D

24. Wire ropes as compared to cotton ropes
A. Are lighter in weight
B. Offer silent operation
C. Can withstand shock loads
D. All of these
Answer : D

25. In composite or reverse laid ropes
A. Direction of twist of wires in strands is opposite to the direction of twist of strands
B. Direction of twist of wires and strands are same
C. Wires in two adjacent strands are twisted in opposite direction
D. Wires are not twisted
Answer : C

26. Shear stress theory is applicable for
A. Ductile materials
B. Brittle materials
C. Elastic materials
D. All of the above
Answer : A

27. The draw of cotter need not exceed
A. 3 mm
B. 5 mm
C. 10 mm
D. 20 mm
Answer : A

28. Eye bolts are used for
A. Foundation purposes
B. Absorbing shock and vibrations
C. Transmission of power
D. Lifting and transportation of machines and cubicles
Answer : D

29. The resilience of a bolt may be increased by
A. Increasing its shank diameter
B. Increasing its length
C. Decreasing its shank diameter
D. Decreasing its length
Answer : B

30. A crankshaft is a __________ shaft.
A. Transmission
B. Machine
C. Machine frame
D. None of these
Answer : B

31. The ultimate strength of steel in tension in comparison to shear is in the ratio of
A. 1 : 1
B. 2 : 1
C. 3 : 2
D. 2 : 3
Answer : C

32. Turn buckle has
A. Right hand threads on bout ends
B. Left hand threads on both ends
C. Left hand threads on one end and right hand threads on other end
D. No threads
Answer : C

33. Oil in journal bearing should be applied at the point where load is
A. Nil or lightest
B. Maximum
C. Average
D. Any one of the above
Answer : A

34. A bench vice has following type of threads
A. Metric
B. Square
C. Buttress
D. Acme
Answer : D

35. Residual stress in materials
A. Acts when external load is applied
B. Becomes zero when external load is removed
C. Is independent of external loads
D. Is always harmful
Answer : C

36. The velocity factor for very accurately cut and ground metallic gears operating at velocities upto __________ are equal to 6/(6 + v).
A. 10 m/s
B. 12.5 m/s
C. 15 m/s
D. 20 m/s
Answer : D

37. In hydrodynamic bearings
A. The oil film pressure is generated only by the rotation of the journal
B. The oil film is maintained by supplying oil under pressure
C. Do not require external supply of lubricant
D. Grease is used for lubrication
Answer : A

38. During hot working of metals,
A. Porosity of the metal is largely eliminated
B. Grain structure of the metal is refined
C. Mechanical properties are improved due of refinement of grains
D. All of the above
Answer : D

39. Slenderness ratio is the ratio of
A. Effective length of column to least radius of gyration of the column
B. Width of column to depth of column
C. Maximum size of column to minimum size of column
D. Effective length of column to width of column
Answer : A

40. The shock absorbing capacity of a bolt can be increased by
A. Tightening it properly
B. Increasing shank diameter
C. Grinding the shank
D. Making shank diameter equal to core diameter of thread.
Answer : D

41. Which process will increase the fatigue duration of parts?
A. Finishing and polishing
B. Shotpeening
C. De-carburisation
D. Electroplating
Answer : B

42. The shear plane in case of bolts should
A. Be across threaded portion of shank
B. Be parallel to axis of bolt
C. Be normal to threaded portion of shank
D. Never be across the threaded portion
Answer : D

43. A flange coupling is used to connect two shafts
A. Which are perfectly aligned
B. Which are not in exact alignment
C. Have lateral misalignment
D. Whose axes intersect at a small angle
Answer : A

44. 18/8 steel contains
A. 18% nickel and 8% chromium
B. 18% chromium and 8% nickel
C. 18% nickel and 8% vanadium
D. 18% vanadium and 8% nickel
Answer : B

45. A key capable of tilting in a recess milled out in a shaft is known as
A. Woodruff key
B. Feather key
C. Flat saddle key
D. Hollow saddle key
Answer : A

46. In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set in order to
A. Reduce vibration
B. Reduce slip
C. Ensure uniform loading
D. Ensure proper alignment
Answer : C

47. An imaginary circle which by pure rolling action gives the same motion as the actual gear, is called
A. Addendum circle
B. Dedendum circle
C. Pitch circle
D. Clearance circle
Answer : C

48. The shearing stresses in the inner face as compared to outer face of the wire in a heavy close coiled spring is
A. Larger
B. Smaller
C. Equal
D. Larger/smaller depending on diameter of spring coil
Answer : A

49. The suitable material for belt used in flour mill is
A. Leather
B. Rubber
C. Canvas or cotton duck
D. Balata gum
Answer : C

50. When a beam of rectangular cross-section of width b and depth d, is subjected to a shear force F, the maximum shear stress induced will be
A. F/bh
B. 3F/2bh
C. 2F/bh
D. 4F/bh
Answer : B