Theory of Machines MCQ Solved Paper for RRB ALP

1. The axis of precession is __________ to the plane in which the axis of spin is going to rotate.
A. Parallel
B. Perpendicular
C. Both A and B
D. None of these
Answer : B

2. Frequency of vibrations is usually expressed in
A. Number of cycles per hour
B. Number of cycles per minute
C. Number of cycles per second
D. None of these
Answer : C

3. The Kutzbach criterion for determining the number of degrees of freedom (n) is (where l = number of links, j = number of joints and h = number of higher pairs)
A. n = 3(l - 1) - 2j - h
B. n = 2(l - 1) -2j - h
C. n = 3(l - 1) - 3j - h
D. n = 2(l - 1) - 3j - h
Answer : A

4. An involute pinion and gear are in mesh. If both have the same size of addendum, then there will be an interference between the
A. Tip of the gear tooth and flank of pinion
B. Tip of the pinion and flank of gear
C. Flanks of both gear and pinion
D. Tip of both gear and pinion
Answer : A

5. The frictional torque transmitted in a truncated conical pivot bearing, considering uniform pressure, is
A. (1/2). ? W cosec? (r? + r?)
B. (2/3). ? W cosec? (r? + r?)
C. (1/2). ? W cosec? [(r?³ - r?³)/(r?² - r?²)]
D. (2/3). ? W cosec? [(r?³ - r?³)/(r?² - r?²)]
Answer : D

6. A point B on a rigid link AB moves with respect to A with angular velocity ? rad/s. The radial component of the acceleration of B with respect to A, is (where vBA = Linear velocity of B with respect to A)
A. v_BA × AB
B. v_BA /AB
C. v²_BA
D. v²_BA /AB
Answer : D

7. 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

8. 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

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

10. 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

11. In a four bar chain or quadric cycle 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 : A

12. Scotch yoke mechanism is used to generate
A. Sine functions
B. Square roots
C. Logarithms
D. Inversions
Answer : A

13. The lead screw of a lathe with nut forms a
A. Rolling pair
B. Sliding pair
C. Screw pair
D. Turning pair
Answer : C

14. 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

15. 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

16. The two elements of a pair are said to form a _________ when they permit relative motion between them.
A. Open pair
B. Kinematic pair
C. Sliding pair
D. None of these
Answer : B

17. 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

18. A reed type tachometer use the principle of
A. Longitudinal vibration
B. Torsional vibration
C. Transverse vibration
D. Damped free vibration
Answer : C

19. The Klein's method of construction for reciprocating engine mechanism
A. Is based on acceleration diagram
B. Is a simplified form of instantaneous center method
C. Utilises a quadrilateral similar to the diagram of mechanism for reciprocating engine
D. Enables determination of Carioles component
Answer : C

20. A flywheel is fitted to the crankshaft of an enginehaving 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

21. When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the ________ pulley must be taken into consideration.
A. Smaller
B. Larger
C. Either A or B
D. None of these
Answer : A

22. Two pulleys of radii r? and r? and at distance x apart are connected by means of a cross belt drive. The length of the belt is
A. ? (r? + r?) + [(r? + r?)²/x] + 2x
B. ? (r? + r?) + [(r? - r?)²/x] + 2x
C. ? (r? - r?) + [(r? - r?)²/x] + 2x
D. ? (r? - r?) + [(r? + r?)²/x] + 2x
Answer : A

23. 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

24. 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

25. In the two rotor system as shown in the below figure (I? < I?), a node of vibration is situated
A. Between I?, and I? but nearer I?
B. Between I?, and I? but nearer to I?
C. Exactly in the middle of the shaft
D. Nearer to I? but outside
Answer : B

26. The steering of a ship means
A. Movement of a complete ship up and down in vertical plane about transverse axis
B. Turning of a complete ship in a curve towards right or left, while it moves forward
C. Rolling of a complete ship sideways
D. None of the above
Answer : B

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

28. The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as
A. Structure
B. Machine
C. Inversion
D. Compound mechanism
Answer : C

29. When the speed of the engine fluctuates continuously above and below the mean speed, the governor is said to be
A. Stable
B. Unstable
C. Isochronous
D. Hunt
Answer : D

30. 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

31. The motion between a pair when limited to a definite direction, irrespective of the direction of force applied, is known as
A. Completely constrained motion
B. Incompletely constrained motion
C. Successfully constrained motion
D. None of these
Answer : A

32. 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

33. The factional torque for square thread at the mean radius r while raising load W is given by
A. T = W.r tan(? - ?)
B. T = W.r tan(? + ?)
C. T = W.r tan?
D. T = W.r tan?
Answer : B

34. 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

35. In a ball bearing, ball and bearing forms a
A. Turning pair
B. Rolling pair
C. Screw pair
D. Spherical pair
Answer : B

36. A mechanism __________ for transmitting or transforming motion.
A. Can be used
B. Cannot be used
C. Unpredictable
D. None of these
Answer : A

37. In a rigid link OA, velocity of A w.r.t. O will be
A. Parallel to OA
B. Perpendicular to OA
C. At 45° to OA
D. Along AO
Answer : B

38. 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

39. A point B on a rigid link AB moves with respect to A with angular velocity ? rad/s. The total acceleration of B with respect to A will be equal to
A. Vector sum of radial component and coriolis component
B. Vector sum of tangential component and coriolis component
C. Vector sum of radial component and tangential component
D. Vector difference of radial component and tangential component
C

40. 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 minimum length of the coupler will be
A. 45 mm
B. Slightly less than 45 mm
C. Slightly more than 45 mm
D. 95 mm
Answer : C

41. The example of successfully constrained motion is a
A. Motion of an I.C. engine valve
B. Motion of the shaft between a footstep bearing
C. Piston reciprocating inside an engine cylinder
D. All of the above
Answer : D

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. 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

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

45. Whitworth quick return mechanism is obtained by inversion of
A. Slider crank mechanism
B. Kinematic chain
C. Five link mechanism
D. Roller cam mechanism
Answer : A

46. A rotary internal combustion engine has __________ cylinders.
A. Four
B. Five
C. Six
D. Seven
Answer : D

47. The power from the engine to the rear axle of an automobile is transmitted by means of
A. Worm and worm wheel
B. Spur gears
C. Bevel gears
D. Hooke's joint
Answer : D

48. The factor which affects the critical speed of a shaft is
A. Diameter of disc
B. Span of shaft
C. Eccentricity
D. All of these
Answer : D

49. The relation between number of links (l) and number of joints (j) in a kinematic chain is
A. l = (1/2).(j + 2)
B. l = (2/3).(j + 2)
C. l = (3/4).(j + 3)
D. l = j + 4
Answer : B

50. The dynamic friction is the friction experienced by a body, when the body
A. Is in motion
B. Is at rest
C. Just begins to slide over the surface of the other body
D. None of the above
Answer : A