Fluid Mechanics MCQs

Question 1

The actual velocity at vena-contracta for flow through an orifice from a reservoir is given by

Accepted Answer

$${{	ext{C}}_{	ext{v}}} \cdot \sqrt {2{	ext{gH}}} $$

Answer

$${{	ext{C}}_{	ext{c}}} \cdot \sqrt {2{	ext{gH}}} $$

Answer

$${{	ext{C}}_{	ext{d}}} \cdot \sqrt {2{	ext{gH}}} $$

Answer

$${{	ext{C}}_{	ext{v}}} \cdot {{	ext{V}}_{	ext{a}}}$$

Question 2

If 'x' is the depth of flow in an open channel of large width, then the hydraulic radius is equal to

Accepted Answer

x

Answer

$$\frac{{	ext{x}}}{2}$$

Answer

$$\frac{{	ext{x}}}{3}$$

Answer

$$\frac{{2{	ext{x}}}}{3}$$

Question 3

In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes

Accepted Answer

Less than liquid vapor pressure

Answer

Less than atmospheric pressure

Answer

More than liquid vapor pressure

Answer

More than atmospheric pressure

Question 4

A compressor that takes suction at a pressure below atmospheric and discharge against atmospheric pressure is called a __________ pump.

Accepted Answer

Vacuum

Answer

Sump

Answer

Volute

Answer

Submerged

Question 5

Check valve is used for __________ flow.

Accepted Answer

Unidirectional

Answer

Very precise control of

Answer

Multidirectional

Answer

None of these

Question 6

A rotameter works on the principle of __________ pressure drop.

Accepted Answer

Constant

Answer

Variable

Answer

Both A & B

Answer

Neither A nor B

Question 7

The continuity equation of fluid mechanics utilises the principle of conservation of

Accepted Answer

Mass

Answer

Momentum

Answer

Energy

Answer

Both B & C

Question 8

Which of the fluid forces are not considered in the Reynold's equation of flow?

Accepted Answer

Compressibility forces

Answer

Viscous forces

Answer

Turbulent forces

Answer

Pressure forces

Question 9

A Bingham fluid of viscosity μ = 10 Pa.s and yield stress, τ0 = 10 KPa, is shared between flat parallel plates separated by a distance of 10-3 m. The top plate is moving with a velocity of 1 m/s. The shear stress on the plate is

Accepted Answer

20 KPa

Answer

10 KPa

Answer

30 KPa

Answer

40 KPa