Theory of Machines 1000+ MCQ with answer for SSC GD

1. The periodic time is given by (where ? = Angular velocity of the particle in rad/s)
A. ?/2?
B. 2?/?
C. ? × 2?
D. ?/?
Answer : B

2. In vibration isolation system, if ?/?n > 1, then the phase difference between the transmitted force and the disturbing force is
A. 0°
B. 90°
C. 180°
D. 270°
Answer : C

3. In a reciprocating steam engine, which of the following forms a kinematic link?
A. Cylinder and piston
B. Piston rod and connecting rod
C. Crankshaft and flywheel
D. Flywheel and engine frame
Answer : C

4. A foot step bearing and rotor of a vertical turbine form examples of
A. Incompletely constrained motion
B. Partially constrained motion
C. Completely constrained motion
D. Successfully constrained motion
Answer : B

5. The absolute acceleration of any point P in a link about center of rotation O is
A. Along PO
B. Perpendicular to PO
C. At 45° to PO
D. None of the above
Answer : D

6. 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

7. In railway axle boxes, the bearing used is
A. Deep groove ball bearing
B. Double row self aligning ball bearing
C. Double row spherical roller bearing
D. Cylindrical roller bearing
Answer : C

8. When a ship travels in a sea, which of the effect is more dangerous
A. Steering
B. Pitching
C. Rolling
D. All of the above
Answer : B

9. Which of the following is a spring controlled governor?
A. Hartnell governor
B. Hartung governor
C. Wilson-Hartnell governor
D. All of these
Answer : D

10. Which of the following mechanism is obtained from lower pair?
A. Gyroscope
B. Pantograph
C. Valve and valve gears
D. All of the above
Answer : D

11. 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

12. Which of the following disciplines provides study of relative motion between the parts of a machine?
A. Theory of machines
B. Applied mechanics
C. Mechanisms
D. Kinematics
Answer : D

13. Power of a governor is the
A. Mean force exerted at the sleeve for a given percentage change of speed
B. Workdone at the sleeve for maximum equilibrium speed
C. Mean force exerted at the sleeve for maximum equilibrium speed
D. None of the above
Answer : D

14. When the body is suspended at the point of suspension, its periodic time and frequency will be ________ as compared to the body suspended at the point of percussion.
A. Same
B. Two times
C. Four times
D. None of these
Answer : A

15. The Ackermann steering mechanism is preferred to the Davis type in automobiles because
A. The former is mathematically accurate
B. The former is having turning pair
C. The former is most economical
D. The former is most rigid
Answer : B

16. The acceleration of the particle moving with simple harmonic motion is _________ at the mean position.
A. Zero
B. Minimum
C. Maximum
D. None of these
Answer : A

17. 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

18. The power of a Porter governor is equal to
A. [c²/(1 + 2c)] (m + M) g.h
B. [2c²/(1 + 2c)] (m + M) g.h
C. [3c²/(1 + 2c)] (m + M) g.h
D. [4c²/(1 + 2c)] (m + M) g.h
Answer : D

19. 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

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. The pressure angle of a cam is the angle between the direction of the follower motion and a normal to the
A. Pitch circle
B. Base circle
C. Pitch curve
D. Prime circle
Answer : C

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

23. For the same lift and same angle of ascent, a smaller base circle will give
A. A small value of pressure angle
B. A large value of pressure angle
C. There is no such relation with pressure angle
D. Something else
Answer : B

24. The rotating shafts tend to vibrate violently at whirling speeds because
A. The system is unbalanced
B. Bearing centre line coincides with the axis
C. The shafts are rotating at very high speeds
D. Resonance is caused due to the heavy mass of the rotor
Answer : D

25. 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

26. The partial balancing of reciprocating parts in locomotives produces
A. Hammer blow
B. Swaying couple
C. Variation in tractive force along the line of stroke
D. All of the above
Answer : D

27. A cam mechanism imparts following motion
A. Rotating
B. Oscillating
C. Reciprocating
D. All of the above
Answer : D

28. The distance by which the __________ of the D-slide valve overlaps the steam port is called exhaust lap.
A. Inner edge
B. Outer edge
C. Corners
D. None of these
Answer : A

29. Which of the following is used to control the speed variations of the engine caused by the fluctuations of the engine turning moment?
A. D-slide valve
B. Governor
C. Flywheel
D. Meyer's expansion valve
Answer : C

30. In a hydrodynamic journal bearing, there is
A. A very thin film of lubricant between the journal and the bearing such that there is contact between the journal and the bearing
B. A thick film of lubricant between the journal and the bearing
C. No lubricant between the journal and the bearing
D. A forced lubricant between the journal and the bearing
Answer : B

31. Which of the following statement is wrong?
A. A round bar in a round hole form a turning pair
B. A square bar in a square hole form a sliding pair
C. A vertical shaft in a foot step bearing forms a successful constraint
D. All of the above
Answer : C

32. The maximum value of the pressure angle in case of cam is kept as
A. 10°
B. 14°
C. 20°
D. 30°
Answer : D

33. A kinematic chain requires at least
A. 2 links and 3 turning pairs
B. 3 links and 4 turning pairs
C. 4 links and 4 turning pairs
D. 5 links and 4 turning pairs
Answer : C

34. The motion between a pair which takes place in __________ is known as incompletely constrained motion.
A. One direction only
B. Two directions only
C. More than one direction
D. None of these
Answer : C

35. Angle of ascent of cam is defined as the angle
A. During which the follower returns to its initial position
B. Of rotation of the cam for a definite displacement of the follower
C. Through which the cam rotates during the period in which the follower remains in highest position
D. Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
Answer : D

36. In a Hartnell governor, the compression of the spring is __________ the lift of the sleeve.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : A

37. If ?/?_n = 2, where co is the frequency of excitation and ?n is the natural frequency of vibrations, then the transmissibility of vibration will the
A. 0.5
B. 1
C. 1.5
D. 2
Answer : B

38. 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

39. Tangential acceleration direction is
A. Along the angular velocity
B. Opposite to angular velocity
C. May be any one of these
D. Perpendicular to angular velocity
Answer : C

40. 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

41. In involute gears, the pressure angle is
A. Dependent on the size of teeth
B. Dependent on the size of gears
C. Always constant
D. Always variable
Answer : C

42. When the sleeve of a Porter governor moves upwards, the governor speed
A. Increases
B. Decreases
C. Remain unaffected
D. First increases and then decreases
Answer : A

43. 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

44. The velocity of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by
A. ?R cos?
B. ?(R - r?) cos?
C. ?(R - r?) sin?
D. ?r? sin?
Answer : C

45. Length of arc of contact is given by
A. Arc of approach - Arc of recess
B. Arc of approach + Arc of recess
C. Arc of approach / Arc of recess
D. Arc of approach × Arc of recess
Answer : B

46. When the pitching of a ship is __________ the effect of gyroscopic couple acting on it will be to move the ship towards port side.
A. Upward
B. Downward
C. Forward
D. Backward
Answer : B

47. 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

48. If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be
A. Stable
B. Unstable
C. Isochronous
D. None of these
Answer : C

49. In a pantograph, all the pairs are
A. Turning pairs
B. Sliding pairs
C. Spherical pairs
D. Self-closed pairs
Answer : A

50. Which of the following statement is correct?
A. The primary unbalanced force is less than the secondary unbalanced force.
B. The primary unbalanced force is maximum twice in one revolution of the crank.
C. The unbalanced force due to reciprocating masses varies in magnitude and direction both.
D. The magnitude of swaying couple in locomotives is inversely proportional to the distance between the two cylinder centre lines
Answer : B