41. The unbalanced primary forces in a reciprocating engine are
balanced completely
balanced partially
balanced by secondary forces
not balanced
✅ The correct answer is option B.
Theory of machines MCQs
42. The secondary unbalanced force is __________ the primary unbalanced force.
one-half
two-third
n times
1/n times
✅ The correct answer is option D.
43. The example of completely constrained motion is a
motion of a piston in the cylinder of a steam engine
motion of a square bar in a square hole
motion of a shaft with collars at each end in a circular hole
all of the above
✅ The correct answer is option D.
44. Due to slip of belt, the velocity ratio of the belt drive increases.
Yes
No
✅ The correct answer is option B.
46. The throw of the eccentric is equal to the valve travel.
Correct
Incorrect
✅ The correct answer is option B.
47. The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction)
α = 45° +
α = 45° –
α = 90° + φ
α = 90° – φ
✅ The correct answer is option B.
48. In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the trans-missibility will be (where ω = Angular speed of the system, ωn = Natural frequency of vibration of the system)
less than unity
equal to unity
greater than unity
zero
✅ The correct answer is option C.
49. The relative velocity of B with respect to A in a rigid link AB is
parallel to AB
perpendicular to AB
along AB
at 45° to AB
✅ The correct answer is option B.
50. The two elements of a pair are said to form a higher pair, when they
have a surface contact when in motion
have a line or point contact when in motion
are kept in contact by the action of external forces, when in motion
permit relative motion
✅ The correct answer is option B.