Fluid Mechanics MCQs

Question 1

Molten soap mass is transported by a __________ pump.

Accepted Answer

Gear

Answer

Diaphragm

Answer

Reciprocating

Answer

Centrifugal

Question 2

Equivalent length of a pipe fitting is

Accepted Answer

Dependent on Reynolds number

Answer

Independent of Reynolds number

Answer

Dependent on the length of the pipe

Answer

None of these

Question 3

Pick out the correct statement pertaining to venturimeter.

Accepted Answer

None of these

Answer

A venturimeter with a fixed pressure drop discharges more, when the flow is vertically downward, than when the flow is vertically upward

Answer

The co-efficient of contraction of a venturimeter is always unity

Answer

For a fixed pressure drop, the discharge of a gas through a venturimeter is greater, when compressibility is taken into account, than when it is neglected

Question 4

With increase in the ratio of orifice diameter to pipe diameter, the fraction of the orifice pressure differential that is permanently lost

Accepted Answer

Decreases

Answer

Increases

Answer

Remains unchanged

Answer

Increases exponentially

Question 5

Self-priming centrifugal pump can be used for

Accepted Answer

All of the above

Answer

Booster service

Answer

Pumping liquid fertilisers (e.g. liquid NH3)

Answer

Pumping industrial wastes

Question 6

For laminar flow of Newtonion fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, $$\mu $$ = fluid viscosity)

Accepted Answer

$$\frac{1}{\mu }$$

Answer

$$\mu $$

Answer

$$\sqrt \mu $$

Answer

$$\frac{1}{{\sqrt \mu }}$$

Question 7

Which of the following equations is valid for laminar flow of a fluid through packed bed?

Accepted Answer

Kozney - Karman equation

Answer

Fanning equation

Answer

Hagen - Poiseuille equation

Answer

Blake - Plummer equation

Question 8

Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about

Accepted Answer

0.62

Answer

0.42

Answer

0.82

Answer

0.98

Question 9

Fanning friction factor for laminar flow of fluid in a circular pipe is

Accepted Answer

Both A and B

Answer

Not a function of the roughness of pipe wall

Answer

Inversely proportional to Reynolds number

Answer

Neither A nor B