1000+ Theory of Machines Multiple Choice Question Answer [Solved]

1. In order to double the period of a simple pendulum, the length of the string should be
A. Halved
B. Doubled
C. Quadrupled
D. None of these
Answer : C

2. Which gear train is used for higher velocity ratios in a small space?
A. Simple gear train
B. Compound gear train
C. Reverted gear train
D. Epicyclic gear train
Answer : D

3. In gramophones for adjusting the speed of the turntable, the following type of governor is commonly employed
A. Hartung governor
B. Wilson Hartnell governor
C. Pickering governor
D. Inertia governor
Answer : C

4. The sense of coriolis component 2 ?v is same as that of the relative velocity vector v rotated at
A. 45° in the direction of rotation of the link containing the path
B. 45° in the direction opposite to the rotation of the link containing the path
C. 90° in the direction of rotation of the link containing the path
D. 180° in the direction opposite to the rotation of the link containing the path
Answer : C

5. In order to give the primary balance of the reciprocating parts of a multi-cylinder inline engines,
A. The algebraic sum of the primary forces must be equal to zero
B. The algebraic sum of the couples about any point in the plane of the primary forces must be equal to zero
C. Both (A) and (B)
D. None of these
Answer : C

6. An automobile steering gear is an example of
A. Sliding pair
B. Rolling pair
C. Lower pair
D. Higher pair
Answer : C

7. The included angle for the V-belt is usually
A. 10° to 20°
B. 20° to 30°
C. 30° to 40°
D. 60° to 80°
Answer : C

8. Hammer blow
A. Is the maximum horizontal unbalanced force caused by the mass provided to balance the reciprocating masses.
B. Is the maximum vertical unbalanced force caused by the mass added to balance the reciprocating masses
C. Varies as the square root of the speed
D. Varies inversely with the square of the speed
Answer : B

9. Longitudinal vibrations are said to occur when the particles of a body moves
A. Perpendicular to its axis
B. Parallel to its axis
C. In a circle about its axis
D. None of these
Answer : B

10. The frictional torque transmitted by a cone clutch is same as that of
A. Flat pivot bearing
B. Flat collar bearing
C. Conical pivot bearing
D. Truncated conical pivot bearing
Answer : D

11. If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
A. Four times the first one
B. Same as the first one
C. One fourth of the first one
D. One and a half times the first one
Answer : C

12. When the belt is stationary, it is subjected to some tension known as initial tension. The value of this tension is equal to the
A. Tension in the tight side of the belt
B. Tension in the slack side of the belt
C. Sum of the tensions on the tight side and slack side of the belt
D. Average tension of the tight side and slack side of the belt
Answer : D

13. The frequency of oscillation at compared to earth will be
A. 6 times more
B. 6 times less
C. 2.44 times more
D. 2.44 times less
Answer : D

14. The secondary unbalanced force is maximum __________ in one revolution of the crank.
A. Two times
B. Four times
C. Eight times
D. Sixteen times
Answer : B

15. When the relation between the controlling force (Fc) and radius of rotation (r) for a spring controlled governor is Fc = ar + b, then the governor will be
A. Stable
B. Unstable
C. Isochronous
D. None of these
Answer : B

16. Klein's construction is useful to determine
A. Velocity of various parts
B. Acceleration of various parts
C. Displacement of various parts
D. Angular acceleration of various parts
Answer : B

17. In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called
A. Fluctuation of energy
B. Maximum fluctuation of energy
C. Coefficient of fluctuation of energy
D. None of these
Answer : A

18. Throw of a cam is the maximum distance of the follower from
A. Base circle
B. Pitch circle
C. Root circle
D. Prime circle
Answer : A

19. Pitch point of a cam is
A. A point on the pitch curve having minimum pressure angle
B. A point on the pitch curve having maximum pressure angle
C. Any point on the pitch curve
D. Any point on the pitch circle
Answer : B

20. A motor car moving at a certain speed takes a left turn in a curved path. If the engine rotates in the same direction as that of wheels, men due to centrifugal forc
A. The reaction on me inne wheels increases and on the outer wheels decreases
B. The reaction on the outer wheels increases and on the inner wheels decreases
C. The reaction on the front wheels increases and on the rear wheels decreases
D. The reaction on the rear wheels increases and on the front wheels decreases
Answer : B

21. Cam size depends upon
A. Base circle
B. Pitch circle
C. Prime circle
D. Outer circle
Answer : A

22. In full depth involute system, the smallest number of teeth in a pinion which meshes with rack without interference is
A. 12
B. 16
C. 25
D. 32
Answer : D

23. When one of the links of a kinematic chain is fixed, the chain is known as a
A. Structure
B. Mechanism
C. Inversion
D. Machine
Answer : B

24. A cam with a roller follower would constitute following type of pair
A. Lower pair
B. Higher pair
C. Open pair
D. Close pair
Answer : B

25. A mass of 1 kg is attached to the end of a spring with a stiffness of 0.7 N/mm. The critical damping coefficient of this system is
A. 1.4 N-s/m
B. 18.52 N-s/m
C. 52.92 N-s/m
D. 529.2 N-s/m
Answer : C

26. The static balancing is satisfactory for low speed rotors but with increasing speeds, dynamic balancing becomes necessary. This is because, the
A. Unbalanced couples are caused only at higher speeds
B. Unbalanced forces are not dangerous at higher speeds
C. Effects of unbalances are proportional to the square of the speed
D. Effects of unbalances are directly proportional to the speed
Answer : C

27. The secondary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is
A. 0° and 90°
B. 180° and 360°
C. Both (A) and (B)
D. None of these
Answer : C

28. The natural frequency of free longitudinal vibrations is equal to (where m = Mass of the body, s = Stiffness of the body, and ? = Static deflection of the body)
A. 1/2? × ?(s/m)
B. 1/2? × ?(g/?)
C. 0.4985/??
D. Any one of these
Answer : D

29. The coriolis component of acceleration depends upon
A. Velocity of slider
B. Angular velocity of the link
C. Both (A) and (B)
D. None of these
Answer : C

30. Which of the following is a turning pair?
A. Piston and cylinder of a reciprocating steam engine
B. Shaft with collars at both ends fitted into a circular hole
C. Lead screw of a lathe with nut
D. Ball and a socket joint
Answer : B

31. Ackermann steering gear consists of
A. Sliding pairs
B. Turning pairs
C. Rolling pairs
D. Higher pairs
Answer : B

32. TJIE horse power transmitted by a belt is dependent upon
A. Tension on tight side of belt
B. Tension on slack side of belt
C. Radius of pulley
D. All of the above
Answer : D

33. If the number of links in a mechanism is equal to l, then the numbers of possible inversions are equal to
A. l - 2
B. l - 1
C. l
D. l + 1
Answer : C

34. The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the left. The effect of gyroscopic couple on the aeroplane will be
A. To dip the nose and tail
B. To raise the nose and tail
C. To raise the nose and dip the tail
D. To dip the nose and raise the tail
Answer : C

35. The frictional torque transmitted in a flat pivot bearing with assumption of uniform pressure is _________ as compared to uniform wear.
A. Less
B. More
C. Same
D. None of these
Answer : B

36. The relation between the controlling force (Fc) and radius of rotation (r) for a stable spring controlled governor is
A. F_c = ar + b
B. F_c = ar - b
C. F_c = ar
D. F_c = a/r + b
Answer : B

37. A body in motion will be subjected to coriolis acceleration when that body is
A. In plane rotation with variable velocity
B. In plane translation with variable velocity
C. In plane motion which is a resultant of plane translation and rotation
D. Restrained to rotate while sliding over another body
Answer : D

38. To obviate axial thrust, following gear drive is used
A. Double helical gears having opposite teeth
B. Double helical gears having identical teeth
C. Single helical gear in which one of the teeth of helix angle a is more
D. Mutter gears
Answer : A

39. A rigid body possesses ________degrees of freedom
A. One
B. Two
C. Four
D. Six
Answer : D

40. If the pressure angle is __________, a reciprocating follower will jam in its bearings.
A. Small
B. Too small
C. Large
D. Too large
Answer : D

41. In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The distance between fixed pivots of crank and followers is
A. 95 mm
B. Slightly less than 95 mm
C. Slightly more than 95 mm
D. 45 mm
Answer : B

42. The velocity of sliding __________ the distance of the point of contact from the pitch point.
A. Is directly proportional to
B. Is inversely proportional to
C. Is equal to cos ? multiplied by
D. Does not depend upon
Answer : A

43. Balancing of rotating and reciprocating parts of an engine is necessary when it runs at
A. Slow speed
B. Moderate speed
C. Highs peed
D. Any one of these
Answer : C

44. Kinematic pairs are those which have
A. Point or line contact between the two elements when in motion
B. Surface contact between the two elements when in motion
C. Elements of pairs not held together mechanically
D. Two elements that permit relative motion
Answer : D

45. When two pulleys are connected by means of a cross belt drive, then both the pulleys will rotate in __________ directions.
A. Same
B. Opposite
C. Perpendicular
D. None of these
Answer : B

46. The moment on the pulley which produces rotation is called
A. Inertia
B. Momentum
C. Moment of momentum
D. Torque
Answer : D

47. The critical speed of a shaft in revolution per second is __________ as that of natural frequency of transverse vibration.
A. Same
B. Different
C. Unpredictable
D. None of these
Answer : A

48. It is required to connect two parallel shafts, the distance between whose axes is small and variable. The shafts are coupled by
A. Universal joint
B. Knuckle joint
C. Oldham's coupling
D. Flexible coupling
Answer : C

49. The coefficient of fluctuation of speed is __________ of maximum fluctuation of speed and the mean speed.
A. Sum
B. Difference
C. Product
D. Ratio
Answer : D

50. In a steam engine, the distance by which the outer edge of the Dslide valve overlaps the steam port is called
A. Lead
B. Steam lap
C. Exhaust lap
D. None of these
Answer : B