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Mechanical Engineering :: Theory of Machine

  1. The inversion of a mechanism is

  2. A.
    changing of a higher pair to a lower pair
    B.
    turning its upside down
    C.
    obtained by fixing different links in a kinematic chain
    D.
    obtained by reversing the input and output motion

  3. The coefficient of fluctuation of energy is the ratio of maximum energy to the minimum energy.

  4. A.
    True
    B.
    False

  5. When the nature of contact between the elements of a pair is such that it can only slide relative to the other, the pair is known as a

  6. A.
    screw pair
    B.
    spherical pair
    C.
    turning pair
    D.
    sliding pair

  7. The velocity of a particle moving with simple harmonic motion, at any instant is given by (where ω = Displacement of the particle from mean position)


  8. The velocity of piston in a reciprocating steam engine is given by (where ω = Angular velocity of crank, r = Radius of crank pin circle, θ = Angle turned by crank from inner dead centre, and n = Ratio of length of connecting rod to the radius of crank)


  9. The primary unbalanced force is maximum __________ in one revolution of the crank.

  10. A.
    twice
    B.
    four times
    C.
    eight times
    D.
    sixteen times

  11. The instantaneous centres which vary with the configuration of mechanism, are called

  12. A.
    permanent instantaneous centres
    B.
    fixed instantaneous centres
    C.
    neither fixed nor permanent instantaneous centres
    D.
    none of the above

  13. The displacement of the reciprocating roller follower, when it has contact with the straight flanks of the tangent cam, is given by (where r1 = Minimum radius of the cam, r2 = Radius of the roller follower, and θ = Angle turned by the cam from the beginning of the follower displacement)

  14. A.
    (r1 - r2)(1 - cosθ)
    B.
    (r1 + r2)(1 + cos θ)
    C.
    (r1 - r2)
    D.
    (r1 + r2)

  15. In considering friction of a V-thread, the virtual coefficient of friction (μ1) is given by

  16. A.
    μ1 = μ sin β
    B.
    μ1 = μ cos β
    C.
    D.

  17. The wear of bearing is proportional to velocity and pressure.

  18. A.
    Yes
    B.
    No