Fluid Mechanics

81. In a free vortex motion, the radial component of velocity everywhere is

  1. maximum
  2. minimum
  3. zero
  4. non-zero and finite
  5. unpredictable.

Correct answer: (C)
zero

82. In a static fluid

  1. resistance to shear stress is small
  2. fluid pressure is zero
  3. linear deformation is small
  4. only normal stresses can exist
  5. viscosity is nil.

Correct answer: (D)
only normal stresses can exist

83. In an immersed body, centre of pressure is

  1. at the centre of gravity
  2. above the centre of gravity
  3. below be centre of gravity
  4. could be above or below e.g. depend¬ing on density of body and liquid
  5. unpredictable.

Correct answer: (C)
below be centre of gravity

84. In an isothermal atmosphere, the pressure

  1. decreases linearly with elevation
  2. remains constant
  3. varies in the same way as the density
  4. increases exponentially with elevation
  5. unpredictable.

Correct answer: (C)
varies in the same way as the density

85. In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than

  1. frictional force
  2. viscosity
  3. surface friction
  4. all of the above
  5. none of the above.

Correct answer: (D)
all of the above

86. In order to increase sensitivity of U-tube manometer, one leg is usually inclined by angle 9. Sensitivity of inclined tube to sensitivity of U-tube is equal to

  1. sin 9
  2. sin 9
  3. cas 9
  4. cos 9
  5. tan 9.

Correct answer: (B)
sin 9

87. In the case of steady flow of a fluid, the acceleration of any fluid particle is

  1. constant
  2. variable
  3. zero
  4. zero under limiting conditions
  5. never zero.

Correct answer: (C)
zero

88. Increase in pressure at the outer edge of a drum of radius R due to rotation at corad/sec, full of liquid of density p will be

  1. pco2/?2
  2. pco2/?2/2
  3. 2pa2R2
  4. pa2R/2
  5. none of the above.

Correct answer: (B)
pco2/?2/2

89. Kinematic viscosity is dependent upon

  1. pressure
  2. distance
  3. level
  4. flow
  5. density.

Correct answer: (E)
density.

90. Kinematic viscosity is equal to

  1. dynamic viscosity/density
  2. dynamicviscosity x density
  3. density/dynamic viscosity
  4. 1/dynamicviscosity x density
  5. same as dynamic viscosity.

Correct answer: (A)
dynamic viscosity/density

Page 9 of 21