Theory of Machines 1000+ MCQ with answer for IBPS Clerk

1. According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centers lie on
A. A triangle
B. A point
C. Two lines
D. A straight line
Answer : D

2. The coefficient of fluctuation of speed is __________ of maximum fluctuation of speed and the mean speed.
A. Sum
B. Difference
C. Product
D. Ratio
Answer : D

3. 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

4. The radial distance from the top of a tooth to the bottom of a tooth in a meshing gear, is called
A. Dedendum
B. Addendum
C. Clearance
D. Working depth
Answer : C

5. 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

6. If the damping factor for a vibrating system is unity, then the system will be
A. Over damped
B. Under damped
C. Critically damped
D. Without vibrations
Answer : C

7. For S.H.M. cam, the acceleration of the follower at the ends of the stroke and aimed stroke respectively, is
A. Maximum and zero
B. Zero and maximum
C. Minimum and maximum
D. Zero and minimum
Answer : A

8. Two heavy rotating masses are connected by shafts of lengths l?, l? and l? and the corresponding diameters are d?, d? and d?. This system is reduced to a torsionally equivalent system having uniform diameter d = d? of the shaft. The equivalent length of the shaft is
A. (l? + l? + l?)/3
B. l = l? + l?.(d?/d?)³ + l?.(d?/d?)³
C. l = l? + l?.(d?/d?)? + l?.(d?/d?)?
D. l? + l? + l?
Answer : C

9. The power transmitted by a belt is maximum when the maximum tension in the belt is _________ of centrifugal tension.
A. One-third
B. Two-third
C. Double
D. Three times
Answer : D

10. The displacement of a flat faced follower when it has contact with the flank of a circular arc cam, is given by (where R = Radius of flank, r? = Minimum radius of the cam, and ? = Angle turned through by the cam)
A. R (1 - cos?)
B. (R - r?) (1 - cos?)
C. R (1 - sin?)
D. (R - r?) (1 - sin?)
Answer : B

11. The D-slide valve is also known as
A. Inside admission valve
B. Outside admission valve
C. Piston slide valve
D. None of these
Answer : B

12. A kinematic chain is known as a mechanism when
A. None of the links is fixed
B. One of the links is fixed
C. Two of the links are fixed
D. None of these
Answer : B

13. 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

14. The unbalanced force due to reciprocating masses
A. Varies in magnitude but constant in direction
B. Varies in direction but constant in magnitude
C. Varies in magnitude and direction both
D. Constant in magnitude and direction both
Answer : A

15. An imaginary circle which by pure rolling action, gives the same motion as the actual gear, is called
A. Addendum circle
B. Dedendum circle
C. Pitch circle
D. Clearance circle
Answer : C

16. The Ackerman steering gear mechanism is preferred to the Davis steering gear mechanism, because
A. Whole of the mechanism in the Ackerman steering gear is on the back of the front wheels
B. The Ackerman steering gear consists of turning pairs
C. The Ackerman steering gear is most economical
D. Both (A) and (B)
Answer : D

17. In a kinematic chain, a quaternary joint is equivalent to
A. One binary joint
B. Two binary joints
C. Three binary joints
D. Four binary joints
Answer : C

18. In its simplest form, a cam mechanism consists of following number of links
A. 1
B. 2
C. 3
D. 4
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. When the belt is stationary, it is subjected to some tension known as initial tension. The value of this tension is equal to the
A. Tension in the tight side of the belt
B. Tension in the slack sid of the belt
C. Sum of the tensions on the tight side and slack side of the belt
D. Average tension of the tight side and slack side of the belt
Answer : D

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

22. There are six gears A, B, C, D, E and F in a compound train. The numbers of teeth in the gears are 20, 60, 30, 80, 25 and 75 respectively. The ratio of angular speeds of the driven (F) to the driver (A) of the drive is
A. 1/24
B. 1/8
C. 4/15
D. 12
Answer : A

23. A shaft has two heavy rotors mounted on it. The transverse natural frequencies, considering each of the rotor separately, are 100 Hz and 200 Hz respectively. The lowest critical speed is
A. 5,367 r.p.m.
B. 6,000 r.p.m.
C. 9,360 r.p.m.
D. 12,000 r.p.m.
Answer : A

24. 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

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

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

27. Critical damping is a function of
A. Mass and stiffness
B. Mass and damping coefficient
C. Mass and natural frequency
D. Damping coefficient and natural frequency
Answer : A

28. 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

29. 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

30. The unbalanced force due to revolving masses
A. Varies in magnitude but constant in direction
B. Varies in direction but constant in magnitude
C. Varies in magnitude and direction both
D. Constant in magnitude and direction both
Answer : B

31. 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

32. In the below figure, PC is the connecting rod and OC is the crank making an angle ? with the line of stroke PO and rotates with uniform angular velocity at ? rad/s. The Klien's acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral CQNO, the acceleration of the piston is _________ when the crank OC and connecting rod PC are at right angles to each other.
A. Infinity
B. Zero
C. Any +ve value
D. Any -ve value
Answer : B

33. 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

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

35. The pitching of a ship produces forces on the bearings which act __________ to the motion of the ship.
A. Vertically and parallel
B. Vertically and perpendicular
C. Horizontally and parallel
D. Horizontally and perpendicular
Answer : D

36. The periodic time of a compound pendulum is __________ when the distance between the point of suspension and the centre of gravity is equal to the radius of gyration of the body about its centre of gravity.
A. Zero
B. Minimum
C. Maximum
D. None of these
Answer : B

37. 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

38. 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

39. In gears, interference takes place when
A. The tip of a tooth of a mating gear digs into the portion between base and root circles
B. Gears do not move smoothly in the absence of lubrication
C. Pitch of the gears is not same
D. Gear teeth are undercut
Answer : A

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

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

42. Longitudinal vibrations are said to occur when the particles of a body moves
A. Perpendicular to its axis
B. Parallel to its axis
C. In a circle about its axis
D. None of these
Answer : B

43. The Hooke's joint consists of:
A. Two forks
B. One fork
C. Three forks
D. Four forks
Answer : A

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

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

46. The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity ?? rad/s in the clockwise direction and the link OB turns with angular velocity ?? rad/s in the anticlockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)
A. ??.??.r
B. (?? - ??) r
C. (?? + ??) r
D. (?? - ??) 2r
Answer : C

47. 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

48. In a mechanism, usually one link is fixed. If the fixed link is changed in a kinematic chain, then relative motion of other links
A. Will remain same
B. Will change
C. Could change or remain unaltered depending on which link is fixed
D. Will not occur
Answer : A

49. Which of the following is a lower pair?
A. Ball and socket i
B. Piston and cylinder
C. Cam and follower
D. Both (A) and (B) above
Answer : D

50. 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