Fluid Mech ref indiabix

Question 1

Hydraulic mean depth (Dm) for a circular pipe of diameter ‘D’ flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum

Answer 1

mean velocity

Question 2

Most commonly used joint in the underground pipe lines is the

Answer 2

sleevejoint

Question 3

Which of the following denotes the effect of compressibility in fluid flow ?

Answer 3

Mach numbe

Question 4

Nominal size of the discharge pipe of a pump is usually __________ the nominal size of the inlet pipe.

Answer 4

Smaller than

Question 5

The terminal velocity of a small sphere settling in a viscous fluid varies as the

Answer 5

inverse of the fluid viscosity.

Question 6

The terminal velocity of a particle moving through a fluid varies as dp^n. What is the value of n’ for Newton’s law regime ?

Answer 6

0.5

Question 7

A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity

Answer 7

one fourth as that of A.

Question 8

The fluid in which the shearing stress within it is proportional to the velocity gradient across the sheared section, is called a __________ fluid.

Answer 8

Newtonion

Question 9

The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10-6m2/s).

Answer 9

0.44

Question 10

For Laminar flow through a packed bed, the pressure drop is proportional to (Vs is the superficial liquid velocity and Dp is the particle diameter)

Answer 10

Vs/Dp2

Question 11

The maximum delivery pressure of compressors can be upto __________ atmospheres.

Answer 11

1000