Theory of Machines 1000+ MCQ with answer for CLAT PG

1. Cam angle 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 the highest position
D. Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
Answer : B

2. 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

3. Kinematic pairs are those which have two elements that
A. Have line contact
B. Have surface contact
C. Permit relative motion
D. Are held together
Answer : C

4. In a spring controlled governor, when the controlling force ________ as the radius of rotation increases, it is said to be a stable governor.
A. Remains constant
B. Decreases
C. Increases
D. None of these
Answer : C

5. 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

6. In order to give the primary balance of the reciprocating parts of a multi-cylinder inline engines,
A. The algebraic sum of the primary forces must be equal to zero
B. The algebraic sum of the couples about any point in the plane of the primary forces must be equal to zero
C. Both (A) and (B)
D. None of these
Answer : C

7. 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

8. A disc is a spinning with an angular velocity ? rad/s about the axis of spin. The couple applied to the disc causing precession will be (where I = Mass moment of inertia of the disc, and ?P = Angular velocity of precession of the axis of spin)
A. (1/2).I?²
B. I?²
C. (1/2). I ? ?_P
D. I ? ?_P
Answer : D

9. The coriolis component of acceleration is taken into account for
A. Slider crank mechanism
B. Four bar chain mechanism
C. Quick return motion mechanism
D. All of these
Answer : C

10. In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called
A. Fluctuation of energy
B. Maximum fluctuation of energy
C. Coefficient of fluctuation of energy
D. None of these
Answer : A

11. The instantaneous centre of a rigid thin disc rolling on a plane rigid surface is located at
A. The centre of the disc
B. The point of contact
C. An infinite distance on the plane surface
D. The point on the circumference situated vertically opposite to the contact point
Answer : B

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

13. 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

14. 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

15. 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

16. 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

17. The driving and driven shafts connected by a Hooke's joint will have equal speeds, if
A. cos? = sin?
B. sin? = ± tan?
C. tan? = ± cos?
D. cot? = cos?
Answer : C

18. 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

19. 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

20. The direction of linear velocity of any point on a link with respect to another point on the same link is
A. Parallel to the link joining the points
B. Perpendicular to the link joining the points
C. At 45° to the link joining the points
D. None of the above
Answer : B

21. When the crank is at the inner dead centre, in a reciprocating steam engine, then the acceleration of the piston will be
A. ?²r. (n + 1)/n
B. ?²r. (n - 1)/n
C. ?²r. n/(n + 1)
D. ?²r. n/(n - 1)
Answer : A

22. 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

23. 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

24. 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

25. The fundamental equation for correct steering is (where ? and ? = Angle through which the axis of the outer wheel and inner wheel turns respectively, c = Distance between the pivots of the front axles, and d = Wheel base)
A. sin? + sin? = b/c
B. cos? - sin? = c/b
C. cot? - cot? = c/b
D. tan? + cot? = b/c
Answer : C

26. The danger of breakage and vibration is maximum
A. Below the critical speed
B. Near the critical speed
C. Above the critical speed
D. None of these
Answer : B

27. Which of the following is a pendulum type governor?
A. Watt governor
B. Porter governor
C. Hartnell governor
D. None of these
Answer : A

28. Two pulleys of radii r? and r? and at distance x apart are connected by means of an open 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 : B

29. To connect two parallel and coplanar shafts the following type of gearing is used
A. Spur gear
B. Bevel gear
C. Spiral gear
D. None of the above
Answer : A

30. In full depth involute system, the smallest number of teeth in a pinion which meshes with rack without interference is
A. 12
B. 16
C. 25
D. 32
Answer : D

31. The pair is known as a higher pair, when the relative motion between the elements of a pair is
A. Turning only
B. Sliding only
C. Rolling only
D. Partly turning and partly sliding
Answer : D

32. 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

33. The load cup of a screw jack is made separate from the head of the spindle to
A. Enhance the load carrying capacity of the jack
B. Reduce the effort needed for lifting the working load
C. Reduce the value of frictional torque required to be countered for lifting the load
D. Prevent the rotation of load being lifted
Answer : D

34. 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

35. The two elements of a pair are said to form a higher pair, when they
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. Permit relative motion
Answer : B

36. A body is said to be under forced vibrations, when
A. There is a reduction in amplitude after every cycle of vibration
B. No external force acts on a body, after giving it an initial displacement
C. A body vibrates under the influence of external force
D. None of the above
Answer : A

37. The moment on the pulley which produces rotation is called
A. Inertia
B. Momentum
C. Moment of momentum
D. Torque
Answer : D

38. If some links are connected such that motion between them can take place in more than one direction, it is called
A. Incompletely constrained motion
B. Partially constrained motion
C. Completely constrained motion
D. Successfully constrained motion
Answer : A

39. A Hartnell governor has its controlling force (Fc) given by Fc = ar + b, where r is the radius of rotation and a and b are constants. The governor becomes isochronous when
A. a is +ve and b = 0
B. a = 0 and b is +ve
C. a is +ve and b is -ve
D. a is +ve and b is also +ve
Answer : A

40. 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

41. 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

42. 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

43. To obviate axial thrust, following gear drive is used
A. Double helical gears having opposite teeth
B. Double helical gears having identical teeth
C. Single helical gear in which one of the teeth of helix angle a is more
D. Mutter gears
Answer : A

44. In a locomotive, the resultant unbalanced force due to the two cylinders along the line of stroke, is known as
A. Tractive force
B. Swaying couple
C. Hammer blow
D. None of these
Answer : A

45. In order to double the period of a simple pendulum, the length of the string should be
A. Halved
B. Doubled
C. Quadrupled
D. None of these
Answer : C

46. Creep in belt drive is due to
A. Material of the pulley
B. Material of the belt
C. Larger size of the driver pulley
D. Uneven extensions and contractions due to varying tension
Answer : D

47. 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

48. The maximum efficiency of spiral gears is (where ? = Shaft angle, and ? = Friction angle)
A. sin (? + ?) + 1/ cos (? - ?) + 1
B. cos (? - ?) + 1/ sin (? + ?) + 1
C. cos (? + ?) + 1/ cos (? - ?) + 1
D. cos (? - ?) + 1/ cos (? + ?) + 1
Answer : C

49. Which of the following has sliding motion?
A. Crank
B. Connecting rod
C. Crank pin
D. Crosshead
Answer : D

50. The unbalanced primary forces in a reciprocating engine are
A. Balanced completely
B. Balanced partially
C. Balanced by secondary forces
D. Not balanced
Answer : B