1000+ Theory of Machines MCQ for SSC JE [Solved]

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

2. A pantograph is a mechanism with
A. Lower pairs
B. Higher pairs
C. Rolling pairs
D. Turning pairs
Answer : A

3. 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

4. With single Hooke's joint it is possible to connect two shafts, the axes of which have an angular misalignment up to
A. 10°
B. 20°
C. 30°
D. 40°
Answer : D

5. Which of the following is an open pair?
A. Ball and socket joint
B. Journal bearing
C. Lead screw and nut
D. Cam and follower
Answer : A

6. A thin circular disc is rolling with a uniform linear speed, along a straight path on a plane surface. Which of the following statement is correct in this regard?
A. All points of the disc have the same velocity
B. The centre of the disc has zero acceleration
C. The centre of the disc has centrifugal acceleration
D. The point on the disc making contact with the plane surface has zero acceleration
Answer : B

7. The magnitude of velocities of the points on a rigid link is
A. Directly proportional to the distance from the points to the instantaneous centre and is parallel to the line joining the point to the instantaneous centre
B. Directly proportional to the distance from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre
C. Inversely proportional to the distance from the points to the instantaneous centre and is parallel to the line joining the point to the instantaneous centre
D. Inversely proportional to the distance from the points to the instantaneous centre and is perpendicular to the line joining the point to the instantaneous centre
Answer : D

8. Two systems shall be dynamically equivalent when
A. The mass of two are same
B. C.G. of two coincides
C. M.I. of two about an axis through e.g. is equal
D. All of the above
Answer : D

9. In order to facilitate starting of locomotive in any position, the cranks of a locomotive with two cylinders, are placed at
A. 45° to each other
B. 90° to each other
C. 120° to each other
D. 180° to each other
Answer : B

10. 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

11. The primary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is
A. 0° and 90°
B. 0° and 180°
C. 90° and 180°
D. 180° and 360°
Answer : B

12. 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

13. A slider crank chain consists of following numbers of turning and sliding pairs
A. 1, 3
B. 2, 2
C. 3, 1
D. 4, 0
Answer : C

14. 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

15. An exact straight line motion mechanism is a
A. Scott-Russell's mechanism
B. Hart's mechanism
C. Peaucellier's mechanism
D. All of these
Answer : D

16. 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

17. Whirling speed of the shaft is the speed at which
A. Shaft tends to vibrate in longitudinal direction
B. Torsional vibrations occur
C. Shaft tends to vibrate vigorously in transverse direction
D. Combination of transverse and longitudinal vibration occurs
Answer : C

18. 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

19. The advantage of the piston valve over the slide valve is that in the former case
A. Wear is less
B. Power absorbed is less
C. Both wear and power absorbed are low
D. The pressure developed being high provides tight sealing
Answer : C

20. A torsional system with discs of moment of inertia I? and I? as shown in the below figure, is gear driven such that the ratio of speed of shaft B to shaft A is 'G'. Neglecting the inertia of gears, the equivalent inertia of disc on shaft B at the speed of shaft A is equal to
A. G.I?
B. G².I?
C. I?/G
D. I?/G²
Answer : B

21. The sense of Coriolis component is such that it
A. Leads the sliding velocity vector by 90°
B. Lags the sliding velocity vector by 90°
C. Is along the sliding velocity vector
D. Leads the sliding velocity vector by 180°
Answer : A

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

23. A governor is said to be stable, if the
A. Radius of rotation of balls increases as the equilibrium speed decreases
B. Radius of rotation of balls decreases as the equilibrium speed decreases
C. Radius of rotation of balls increases as the equilibrium speed increases
D. Radius of rotation of balls decreases as the equilibrium speed increases
Answer : C

24. The relation between number of pairs (p) forming a kinematic chain and the number of links (l) is
A. l = 2p - 2
B. l = 2p - 3
C. l = 2p - 4
D. l = 2p - 5
Answer : C

25. In a cam drive with uniform velocity follower, the sharp corners of the displacement diagram are rounded off at the beginning and at the end of each stroke. This is done
A. Because of difficulty in manufacturing cam profile
B. Because of loose contact of follower with cam surface
C. In order to have acceleration in beginning and retardation at the end of stroke within the finite limits
D. Because the uniform velocity motion is a partial parabolic motion
Answer : C

26. The coriolis component of acceleration exists whenever a point moves along a path that has
A. Linear displacement
B. Rotational motion
C. Gravitational acceleration
D. Tangential acceleration
Answer : B

27. 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

28. A shaft carrying two rotors at its ends will have
A. No node
B. One node
C. Two nodes
D. Three nodes
Answer : B

29. A flywheel is fitted to the crankshaft of an engine having W as the amount of indicated work per revolution and permissible limits of coefficient of fluctuation of energy and speed as CE and CS respectively. The kinetic energy of the flywheel is given by
A. 2 W C_E / C_S
B. W C_E / 2C_S
C. W C_E / C_S
D. W C_S / 2C_E
Answer : B

30. When a shaking force is transmitted through the springs, damping becomes detrimental when the ratio of its frequency to the natural frequency is greater than
A. 0.25
B. 0.5
C. 1
D. 2
Answer : D

31. A universal joint is an example of
A. Higher pair
B. Lower pair
C. Rolling pair
D. Sliding pair
Answer : B

32. A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the centre of bigger gear is
A. 2
B. 3
C. 4
D. 5
Answer : C

33. The balancing weights are introduced in planes parallel to the plane of rotation of the disturbing mass. To obtain complete dynamic balance, the minimum number of balancing weights to be introduced in different planes is
A. 1
B. 2
C. 3
D. 4
Answer : B

34. For dynamic balancing of a shaft
A. The net dynamic force acting on the shaft is equal to zero
B. The net couple due to the dynamic forces acting on the shaft is equal to zero
C. Both (A) and (B)
D. None of the above
Answer : C

35. Oldham's coupling is the
A. Second inversion of double slider crank chain
B. Third inversion of double slider crank chain
C. Second inversion of single slider crank chain
D. Third inversion of slider crank chain
Answer : B

36. The arrangement is called bevel gearing, when two __________ are connected by gears.
A. Intersecting and coplanar shafts
B. Nonintersecting and non-coplanar shafts
C. Parallel and coplanar shafts
D. Parallel and non-coplanar shafts
Answer : A

37. The inversion of a mechanism is
A. Changing of a higher pair to a lower pair
B. Turning its upside down
C. Obtained by fixing different links in a kinematic chain
D. Obtained by reversing the input and output motion
Answer : C

38. 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

39. The frictional torque transmitted in a conical 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

40. In automobiles the power is transmitted from gear box to differential through
A. Bevel gear
B. Universal joint
C. Hooke's joint
D. Knuckle joint
Answer : C

41. Which of the following is an example of a higher pair?
A. Toothed gearing
B. Belt and rope drive
C. Ball and roller bearing
D. All of these
Answer : D

42. The height of a Watt's governor (in metres) is equal to (where N = Speed of the arm and ball about the spindle axis)
A. 8.95/N²
B. 89.5/N²
C. 895/N²
D. 8950/N²
Answer : C

43. 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

44. 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

45. 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

46. The cam and follower is an example of
A. Sliding pair
B. Rolling pair
C. Lower pair
D. Higher pair
Answer : D

47. The acceleration of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by
A. ?². (r? r?). (1 - cos² ?)
B. ?². (r? + r?). (1 + cos² ?)
C. ?². (r? + r?). [(2 - cos² ?)/cos³ ?]
D. ?². (r? - r?). (1 - sin² ?)
Answer : C

48. A pulley and belt in a belt drive form a
A. Cylindrical pair
B. Turning pair
C. Rolling pair
D. Sliding pair
Answer : B

49. The natural frequency of free transverse vibrations due to a point load acting over a simply supported shaft is equal to (where ? = Static deflection of a simply supported shaft due to the point load)
A. 0.4985/??
B. 0.5615/??
C. 0.571/??
D. 0.6253/??
Answer : A

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