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Mechanical Engineering :: Machine Design

  1. According to Lame's equation, the thickness of a cylinder is equal to (where d = Inner diameter of cylinder, p = Internal pressure, and μ = Poisson's ratio. )

  2. A.

    \(\frac { d } { 2 } [\sqrt{\frac{\sigma_t + (1- 2\mu)\rho}{\sigma_t -(1+ \mu)\rho}} -1 ]\)

    B.

    \(\frac { d } { 2 } [\sqrt{\frac{\sigma_t + (1- \mu)\rho}{\sigma_t -(1+ \mu)\rho}} -1 ]\)

    C.

    \(\frac { d } { 2 } [\sqrt{\frac{\sigma_t + \rho}{\sigma_t - \rho}} -1 ]\)

    D.

    none of these


  3. If T is the actual number of teeth on a helical gear and φ is the helix angle for the teeth, then formative number of teeth is written as

  4. A.

    T sec3 φ

    B.

    T sec2 φ

    C.

    T/sec3 φT cosec φ

    D.

    T cosec φ


  5. The material generally used for air-craft components is

  6. A.

    mild steel

    B.

    high speed steel

    C.

    stainless steel

    D.

    aluminium


  7. The speed of the sprocket reduces as the chain pitch __________ for a given number of teeth.

  8. A.

    increases

    B.

    decreases


  9. In an oil lubricated journal bearing, the coefficient of friction between the journal and the bearing

  10. A.

    remains constant at all speeds

    B.

    is minimum at zero speed and increases monotonically with increase in speed

    C.

    is maximum at zero speed and decreases monotonically with increase in speed

    D.

    becomes minimum at an optimum speed and then increases with further increase in speed