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Civil Engineering :: Applied Mechanics

  1.  

    When a body of mass M1 is hanging freely and an other of mass M2 lying on a smooth inclined plane(α) are connected by a light indextensible string passing over a smooth pulley, the acceleration of the body of mass M1, will be given by

  2. A.

    \(\frac { g(M1+M2 sina) } { M1+M2 } \) m/sec

    B.

    \(\frac { g(M1-M2 sina) } { M1+M2 } m/sec^2\) 

    C.

    \(\frac { g(M2+M1 sina) } { M1+M2 } m/sec^2\)

    D.

    \(\frac { g(M2*M1 sina) } { M2-M1 } m/sec^2\)


  3. According to Law of Triangle of Forces

  4. A.

    three forces acting at a point, can be rep-resented by the sides of a triangle, each side being in proportion to the force

    B.

    three forces acting along the sides of a triangle are always in equilibrium

    C.

    if three forces acting on a, point can be represented.in magnitude and direction, by the sides of a triangle taken in order, these will be in equilibrium

    D.

    if three forces acting at a point are in equilibrium each force is proportional to the sine of the angle between the other two

    E.

    if the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle taken in order, their resultant will be represented in magnitude and direction by the third side of the triangle, taken in opposite order.


  5. A Second's pendulum gains 2 minutes a day. To make it to keep correct time its length

  6. A.

    must be decreased

    B.

    must be increased

    C.

    is not changed but weight of the bob is increased

    D.

    is not changed but weight of the bob is decreased

    E.

    none of these.


  7.  

    The following is not a law of static friction :

  8. A.

    The force of friction always acts in a direction opposite to that in which the body tends to move

    B.

    The force of friction is dependent upon the area of contact

    C.

    The force of friction depends upon the roughness of the surface

    D.

    The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces.


  9.  

    The velocity of a moving body, is

  10. A.

    a vector quantity

    B.

    a scalar quantity

    C.

    a scalar as well as a vector quantity

    D.

    none of these.


  11.  

    A spring scale in a stationary lift shows a reading of 60 kg for a man standing on it. If the lift starts descending at an acceleration of g/5, the scale reading would be

  12. A.

    48 kg

    B.
    60 kg
    C.

    72 kg

    D.

    none of these.


  13.  

    The resolved part of the resultant of two forces inclined at an angle θ in a given direction is

  14. A.

    algebraic sum of the resolved parts of the forces in the direction

    B.

    arithmetical sum of the resolved parts of the forces in the direction

    C.

    difference of the forces multiplied by cosine θ°

    D.

    sum of the forces multiplied by the sine θ

    E.

    sum of the forces multiplied by the tangent θ°.


  15. The velocity ratio of the differential wheel and axle is

  16. A.

    \(\frac { R } { r1-r2 } \)

    B.

    \(\frac { 2R } { r1 } \)

    C.

    \(\frac {3 R } { r1-r2 } \)

    D.

    \(\frac {2 R } { r1+r2 } \)


  17. The following statement is one of the laws of Dynamic friction

  18. A.

    The force of friction always acts in a direction opposite to that in which a body is moving

    B.

    The magnitude of the kinetic friction bears a constant ratio to the normal reaction between two surfaces. The ratio being slightly less than that in the case of limiting friction

    C.

    For moderate speeds the force of friction remains constant but decreases slightly with the increase of speed

    D.

    all the above.


  19. A 50 kg boy climbs up a 8 m rope in gymnasiam in 10 sec. The average power developed by the boy is approximately

  20. A.

    400 watts

    B.

    500 watts

    C.

    4000 watts

    D.
    none of these.