Fluid Mechanics MCQs

Question 1

For a given Reynold number as d/D for an orifice increases, Cd will (where, d & D are orifice & pipe diameters respectively).

Accepted Answer

Increase

Answer

Decrease

Answer

Remain constant

Answer

Either A or B; depends on other factors

Question 2

Vena-contracta pressure tapping is at a distance __________ from the position of an orificemeter fitted in a pipe of internal diameter 'd'

Accepted Answer

0.5d

Answer

d

Answer

2d

Answer

4d

Question 3

I.D. of 1/4" schedule 40 pipe is 0.364". I.D. of a 1/2" schedule 40 pipe would be __________ inch

Accepted Answer

0.622

Answer

4.728

Answer

0.5

Answer

0.474

Question 4

The valve commonly used in pipes larger than 2" dia is a

Accepted Answer

Gate valve

Answer

Globe valve

Answer

Plug-cock

Answer

Check valve

Question 5

If in a flow field, between any two points, then the flow must be

Accepted Answer

Steady, incompressible, irrotational

Answer

Steady, compressible, irrotational

Answer

Steady, compressible and along a streamline

Answer

Unsteady, incompressible, irrotational

Question 6

Which of the following factors does not contribute to the pressure drop in a pipeline ?

Accepted Answer

None of these

Answer

Velocity of fluid

Answer

Size of pipe

Answer

Length of pipe and number of bends

Question 7

A piezometer provided in the pipe measures

Accepted Answer

Static pressure

Answer

Friction factor

Answer

Dynamic pressure

Answer

None of these

Question 8

Air vessel of a reciprocating pump is initially filled with

Accepted Answer

Compressed air

Answer

Atmospheric air

Answer

Water

Answer

None of these

Question 9

The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is

Accepted Answer

2(Ro - Ri)

Answer

4(Ro - Ri)

Answer

$$\sqrt {{{	ext{R}}_{	ext{o}}} - {{	ext{R}}_{	ext{i}}}} $$

Answer

Ro + Ri