SSC MTS - Theory of Machines 1000+ MCQ [Solved] PDF Download

1. V-belts are usually used for
A. Long drives
B. Short drives
C. Long and short drives
D. None of these
Answer : B

2. 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

3. The example of spherical pair is
A. Bolt and nut
B. Lead screw of a lathe
C. Ball and socket joint
D. Ball bearing and roller bearing
Answer : C

4. 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

5. Lower 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 : B

6. The dedendum circle diameter is equal to (where, ? = Pressure angle)
A. Pitch circle dia. × cos?
B. Addendum circle dia. × cos?
C. Clearance circle dia. × cos?
D. Pitch circle dia. × sin?
Answer : A

7. For high speed engines, the cam follower should move with
A. Uniform velocity
B. Simple harmonic motion
C. Uniform acceleration and retardation
D. Cycloidal motion
Answer : D

8. Sensitiveness of the governor is defined as the ratio of the
A. Mean speed to the maximum equilibrium speed
B. Mean speed to the minimum equilibrium speed
C. Difference of the maximum and minimum equilibrium speeds to the mean speed
D. Sum of the maximum and minimum equilibrium speeds to the mean speed
Answer : C

9. The velocity of a body moving with simple harmonic motion is __________ at the mean position.
A. Zero
B. Minimum
C. Maximum
D. None of these
Answer : C

10. 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

11. The periodic time of one oscillation for a simple pendulum is
A. 2?. ?(g/l)
B. (1/2?). ?(g/l)
C. 2?. ?(l/g)
D. (1/2?). ?(l/g)
Answer : C

12. The maximum velocity of a particle moving with simple harmonic motion is
A. ?
B. ?r
C. ?²r
D. ?/r
Answer : B

13. Creep in belt drive is due to
A. Weak material of the belt
B. Weak material of the pulley
C. Uneven extensions and contractions of the belt when it passes from tight side to slack side
D. Expansion of the belt
Answer : C

14. 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

15. The natural frequency of free torsional vibrations of a shaft is equal to (where q = Torsional stiffness of the shaft, and I = Mass moment of inertia of the disc attached at the end of a shaft)
A. 2?. ?(q/I)
B. 2? qI
C. (1/2?). ?(q/I)
D. 1/2?
Answer : C

16. Which is the false statement about the properties of instantaneous centre?
A. At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered
B. The two rigid links have no linear velocities relative to each other at the instantaneous centre
C. The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link
D. The double centre can be denoted either by O2 or O12, but proper selection should be made
Answer : D

17. A typewriter mechanism has 7 numbers of binary joints, six links and none of higher pairs. The mechanism is
A. Kinematically sound
B. Not sound
C. Soundness would depend upon which link is kept fixed
D. Data is not sufficient to determine same
Answer : A

18. In a simple train of wheels, the velocity ratio __________ the intermediate wheels.
A. Depends upon
B. Is independent of
C. Either A or B
D. None of these
Answer : B

19. The effort of a Porter governor is equal to (where c = Percentage increase in speed, m = Mass of ball, and M = Mass on the sleeve)
A. c (m - M) g
B. c (m + M) g
C. c/(m + M) g
D. c/(m - M) g
Answer : B

20. Consider the following mechanisms:
1. Oscillating cylinder engine mechanism
2. Toggle mechanism
3. Radial cylinder engine mechanism
4. Quick return mechanism Which of the above are inversions of slider crank mechanism?
A. 1, 2 and 4
B. 2, 3 and 4
C. 1, 2 and 3
D. 1, 3 and 4
Answer : D

21. Which of the following statement is correct as regard to the difference between a machine and a structure?
A. The parts of a machine move relative to one another, whereas the members of a structure do not move relative to one another
B. The links of a machine may transmit both power and motion, whereas the members of a structure transmit forces only
C. A machine transforms the available energy into some useful work, whereas in a structure no energy is transformed into useful work
D. All of the above
Answer : D

22. Which of the following disciplines provides study of inertia forces arising from the combined effect of the mass and the motion of the parts?
A. Theory of machines
B. Applied mechanics
C. Mechanisms
D. Kinetics
Answer : D

23. A rigid body, under the action of external forces, can be replaced by two masses placed at a fixed distance apart. The two masses form an equivalent dynamical system, if
A. The sum of the two masses is equal to the total mass of body
B. The centre of gravity of the two masses coincides with that of the body
C. The sum of mass moment of inertia of the masses about their centre of gravity is equal to the mass moment of inertia of the body
D. All of the above
Answer : D

24. Cross head and guides form a
A. Lower pair
B. Higher pair
C. Turning pair
D. Sliding pair
Answer : D

25. In a shaper mechanism, the Coriolis component of acceleration will
A. Not exist
B. Exist
C. Depend on position of crank
D. None of the above
Answer : B

26. 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

27. The frequency of oscillation of a compound pendulum is
A. 2?. ?[gh/(k_G² + h²)]
B. 2?. ?[(k_G² + h²)/gh]
C. (1/2?). ?[gh/(k_G² + h²)]
D. (1/2?). ?[(k_G² + h²)/gh]
Answer : C

28. 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

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. When two links are connected by a pin joint, their instantaneous centre lies
A. On their point of contact
B. At the centre of curvature
C. At the centre of circle
D. At the pin joint
Answer : D

31. For simple harmonic motion of the of follower, a cosine curve represents
A. Displacement diagram
B. Velocity diagram
C. Acceleration diagram
D. All of the above
Answer : C

32. When the two elements of a pair have __________ when in motion, it is said to a lower pair.
A. Line or point contact
B. Surface contact
C. Body contact
D. None of these
Answer : B

33. Relationship between the number of links (L) and number of pairs (P) is
A. P = 2L - 4
B. P = 2L + 4
C. P = 2L + 2
D. P = 2L - 2
Answer : C

34. In a single slider crank chain
A. Each of the four pairs is a turning pair
B. One is a turning pair and three are sliding pairs
C. Two are turning pairs and two are sliding pairs
D. Three are turning pairs and one is a sliding pair
Answer : D

35. In vibration isolation system, if ?/?n < 2, then for all values of damping factor, the transmissibility will be (where ? = Angular speed of the system, ?n = Natural frequency of vibration of the system)
A. Less than unity
B. Equal to unity
C. Greater than unity
D. Zero
Answer : C

36. The Scott-Russell mechanism consists of
A. Sliding and turning pairs
B. Sliding and rotary pairs
C. Turning and rotary pairs
D. Sliding pairs only
Answer : A

37. The tractive force is maximum or minimum when the angle of inclination of crank with the line of stroke (?) is equal to
A. 0° and 90°
B. 90° and 180°
C. 135° and 315°
D. 270° and 360°
Answer : B

38. A point on a link connecting double slider crank chain traces a
A. Ellipse
B. Circle
C. Parabola
D. Hyperbola
Answer : A

39. In multi V-belt transmission, if one of the belt is broken, we have to change the
A. Broken belt
B. Broken belt and its adjacent belts
C. All the belts
D. There is no need of changing any one as remaining belts can take care of transmission of load
Answer : C

40. 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

41. The purpose of a link is to
A. Transmit motion
B. Guide other links
C. Act as a support
D. All of the above
Answer : D

42. A single degree of freedom system is given by, m × (d²x/dt²) + c × (dx/dt) + sx = F.cos?.t with usual notations. It represents
A. Free vibration with damping
B. Free vibration without damping
C. Forced vibration with damping
D. Forced vibration without damping
Answer : C

43. The equation of motion for a vibrating system with viscous damping is (d²x/dt²) + (c/m).(dx/dt) + (s/m).x = 0, if the roots of the equation are __________ then the system will be under damped.
A. Equal
B. Real
C. Complex conjugate
D. None of these
Answer : C

44. 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

45. The stress induced in a body will be shear stress, when it is subjected to
A. Longitudinal vibrations
B. Transverse vibrations
C. Torsional vibrations
D. None of these
Answer : C

46. The frequency of oscillation of a torsional pendulum is
A. 2?k/r. ?(g/l)
B. r/2?k. ?(l/g)
C. 2?r/k. ?(g/l)
D. r/2?k. ?(g/l)
Answer : D

47. The size of cam depends upon
A. Base circle
B. Pitch circle
C. Prime circle
D. Pitch curve
Answer : A

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

49. The velocity of any point in mechanism relative to any other point on the mechanism on velocity polygon is represented by the line
A. Joining the corresponding points
B. Perpendicular to line as per (A)
C. Not possible to determine with these data
D. At 45° to line as per (A)
Answer : A

50. The swaying couple is maximum or minimum when the angle of inclination of the crank to the line of stroke (?) is equal to
A. 90° and 180°
B. 45° and 225°
C. 180° and 270°
D. 270° and 360°
Answer : B