Engineering :: Fluid Mechanics and Hydraulic Machines

@ : Home > Mechanical Engineering > Fluid Mechanics and Hydraulic Machines

91.

In the theory of lubrication the assumption is made that

A.	The velocity distribution is the same at all cross-sections	B.	The velocity distribution at any section is the same as if the plates were parallel
C.	The pressure variation along the bearing is the same as if the plates were parallel	D.	The velocity varies linearly between the two surfaces
E.	The velocity varies linearly between the two surfaces

92.

The distance r from the centre of a tube of radius r0 where the average velocity occurs in laminar flow is

93.

The Reynolds number for flow of 0.3 m3/s of oil sp. Gr. 0.86,

94.

The result of pressure of a liquid on the wetted surface of a rigid body is

A.	The single force which, acting at a point on that surface would produce the same effect on the body as the liquid pressure on it	B.	The single resultant force acting on the body
C.	The point where vertical component of resulting force is zero	D.	The single point where resultant horizontal force is zero
E.	None of the above

95.

The Boundary layer on a flat plate is calld laminar boundary layer if

A.	Reynold No. is less than 2000	B.	Reynold No. is less that 4000
C.	Reynold No. is less than 5 x 105	D.	None of the above

96.

Which two forces are most important in laminar flow between closely spaced parallel plates

97.

Which two forces are most important in floating bodies

98.

A piece of metal of specific gravity 3.4 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury

99.

A piece of cork weighing 4 kg floats in water with 40% of its volume under the liquid. Determine specific gravity of cork.

100.

The line of action of the buoyant force acts through the

A.	Centre of gravity of any submerged body	B.	Centroid of gravity of any floating body
C.	Centroid of the displaced volume of fluid	D.	Centroid of the volume of fluid vertically above the body
E.	Centroid of the horizontal projection of the body