Theory of Machines 1000+ MCQ with answer for CEED

1. Higher 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 : A

2. In a flat collar pivot bearing, the moment due to friction is proportional to
A. (r?² - r?²)/(r? - r?)
B. (r?² - r?²)/(r? + r?)
C. (r?³ - r?³)/(r?² - r?²)
D. (r?³ - r?³)/(r? - r?)
Answer : C

3. A Porter governor is a
A. Pendulum type governor
B. Dead weight governor
C. Spring loaded governor
D. Inertia governor
Answer : B

4. Oldhams coupling is an inversion of the kinematic chain used in
A. Whitworth quick return mechanism
B. Elliptical trammels
C. Rotary engine
D. Universal joint
Answer : B

5. In S.H.M., acceleration is proportional to
A. Velocity
B. Displacement
C. Rate of change of velocity
D. All of the above
Answer : B

6. A shaft has an attached disc at the centre of its length. The disc has its centre of gravity located at a distance of 2 mm from the axis of the shaft. When the shaft is allowed to vibrate in its natural bow-shaped mode, it has a frequency of vibration of 10 rad/s. When the shaft is rotated at 300 r.p.m., it will whirl with a radius of
A. 2 mm
B. 2.22 mm
C. 2.50 mm
D. 3.0 mm
Answer : B

7. In which of the following type of gear train the first gear and the last gear are co-axial.
A. Simple gear train
B. Compound gear train
C. Reverted gear train
D. None of the above
Answer : C

8. When the particles of a body moves perpendicular to its axis, then the body is said to have
A. Longitudinal vibration
B. Transverse vibration
C. Torsional vibration
D. None of these
Answer : B

9. The total number of instantaneous centres for a mechanism consisting of n links are
A. n/2
B. n
C. n - 1
D. n(n - 1)/2
Answer : D

10. 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

11. In a disc clutch, if there are n? number of discs on the driving shaft and n? number of discs on the driven shaft, then the number of pairs of contact surfaces will be
A. n? + n?
B. n? + n? + 1
C. n? + n? - 1
D. n? + n? - 2
Answer : C

12. 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

13. In a steam engine, the link constitutes a
A. Piston, piston rod and crosshead
B. Connecting rod with big and small end brasses, caps and bolts
C. Crank pin, crankshaft and flywheel
D. All of the above
Answer : D

14. 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

15. The unbalanced force due to revolving masses
A. Varies in magnitude but constant in direction
B. Varies in direction but constant in magnitude
C. Varies in magnitude and direction both
D. Constant in magnitude and direction both
Answer : B

16. The efficiency of a screw jack is maximum, when (where ? = Helix angle, and ? = Angle of friction)
A. ? = 45° + ?/2
B. ? = 45° - ?/2
C. ? = 90° + ?
D. ? = 90° - ?
Answer : B

17. 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

18. Governor is used in automobile to
A. Decrease the variation of speed
B. Maximize the fuel economy
C. Limit the vehicle speed
D. Maintain constant engine speed
Answer : C

19. In an open pair, the two elements of a pair
A. Have a surface contact when in motion
B. Have a line or point contact when in motion
C. Are kept in contact by the action of external forces, when in motion
D. Are not held together mechanically
Answer : D

20. In steady state forced vibrations, the amplitude of vibrations at resonance is __________ damping coefficient.
A. Equal to
B. Directly proportional to
C. Inversely proportional to
D. Independent of
Answer : C

21. Klein's construction can be used to determine acceleration of various parts when the crank is at
A. Inner dead centre
B. Outer dead centre
C. Right angles to the link of the stroke
D. All of the above
Answer : D

22. In its simplest form, a cam mechanism consists of following number of links
A. 1
B. 2
C. 3
D. 4
Answer : C

23. The ratio of height of Porter governor (when length of arms and links are equal) to the height of Watt's governor is (where m = Mass of the ball, and M = Mass on the sleeve)
A. m/(m + M)
B. M/(m + M)
C. (m + M)/m
D. (m + M)/M
Answer : C

24. The acceleration of a particle at any instant has two components i.e. radial component and tangential component. These two components will be
A. Parallel to each other
B. Perpendicular to each other
C. Inclined at 45°
D. Opposite to each other
Answer : B

25. Elements of pairs held together mechanically is known as
A. Closed pair
B. Open pair
C. Mechanical pair
D. Rolling pair
Answer : A

26. The contact ratio for gears is
A. Zero
B. Less than one
C. Greater than one
D. Infinity
Answer : C

27. Which of the following statement is correct for gears?
A. The addendum is less than the dedendum
B. The pitch circle diameter is the product of module and number of teeth
C. The contact ratio means the number of pairs of teeth in contact
D. All of the above
Answer : D

28. A mechanism is an assemblage of
A. Two links
B. Three links
C. Four or more than four links
D. All of these
Answer : C

29. The maximum or minimum value of the swaying couple is
A. ± c.m.?².r
B. ± a (1 - c) m.?².r
C. ± (a/?2) (1 - c) m.?².r
D. ± 2a (1 - c) m.?².r
Answer : C

30. The Hooke's joint consists of:
A. Two forks
B. One fork
C. Three forks
D. Four forks
Answer : A

31. The coriolis component of acceleration leads the sliding velocity by
A. 45°
B. 90°
C. 135°
D. 180°
Answer : B

32. The number of links in pantograph mechanism is equal to
A. 2
B. 3
C. 4
D. 5
Answer : C

33. At the nodal point in a shaft, the amplitude for torsional vibration will be
A. Minimum
B. Maximum
C. Zero
D. Infinity
Answer : C

34. The type of gears used to connect two non parallel and non intersecting shafts is
A. Spur gear
B. Helical gear
C. Bevel gear
D. Spiral gear
Answer : D

35. In a Hartnell governor, the stiffness of the spring is given by (where S1 and S2 = Spring forces exerted on the sleeve at max. and min. radii of rotation, and h = Compression of the spring)
A. (S? + S?)/h
B. (S? - S?)/h
C. (S? + S?)/2h
D. (S? - S?)/2h
Answer : B

36. The maximum fluctuation of energy is the
A. Difference between the maximum and minimum energies
B. Sum of the maximum and minimum energies
C. Variations of energy above and below the mean resisting torque line
D. Ratio of the mean resisting torque to the workdone per cycle
Answer : A

37. What is the number of instantaneous centres for an eight link mechanism?
A. 15
B. 28
C. 30
D. 8
Answer : B

38. The maximum efficiency of a screw jack is
A. (1 - sin?)/(1 + sin?)
B. (1 + sin?)/(1 - sin?)
C. (1 - tan?)/(1 + tan?)
D. (1 + tan?)/(1 - tan?)
Answer : A

39. The centre of gravity of a coupler link in a four bar mechanism will experience
A. No acceleration
B. Only linear acceleration
C. Only angular acceleration
D. Both linear and angular acceleration
Answer : D

40. The unbalanced force due to reciprocating masses
A. Varies in magnitude but constant in direction
B. Varies in direction but constant in magnitude
C. Varies in magnitude and direction both
D. Constant in magnitude and direction both
Answer : A

41. In under damped vibrating system, if x? and x? are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to
A. x?/x?
B. log(x?/x?)
C. log_e(x?/x?)
D. log(x?.x?)
Answer : B

42. Which of the following is an open pair?
A. Journal bearing
B. Ball and Socket joint
C. Leave screw and nut
D. None of the above
Answer : C

43. When the radius of rotation of balls __________ as the equilibrium speed increases, the governor is said to be unstable.
A. Remains constant
B. Decreases
C. Increases
D. None of these
Answer : B

44. When the nature of contact between the elements of a pair is such that it can only slide relative to the other, the pair is known as a
A. Screw pair
B. Spherical pair
C. Turning pair
D. Sliding pair
Answer : D

45. The minimum force required to slide a body of weight W on a rough horizontal plane is
A. W sin?
B. W cos?
C. W tan?
D. W cosec?
Answer : A

46. In a vibrating system, if the actual damping coefficient is 40 N/m/s and critical damping coefficient is 420 N/m/s, then logarithmic decrement is equal to
A. 0.2
B. 0.4
C. 0.6
D. 0.8
Answer : C

47. A spring controlled governor is said to be isochronous when the controlling force
A. Increases as the radius of rotation decreases
B. Increases as the radius of rotation increases
C. Decreases as the radius of rotation increases
D. Remain constant for all radii of rotation
Answer : D

48. The amplitude of vibration is always __________ the radius of the circle.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : A

49. Which of the following is an inversion of a single slider crank chain?
A. Pendulum pump
B. Oscillating cylinder engine
C. Rotary internal combustion engine
D. All of these
Answer : D

50. 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 inner 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