Fluid Mechanics MCQs

Question 1

In deriving Bernoulli's equation, fluid is assumed to be

Accepted Answer

Incompressible, frictionless, steady, along a streamline

Answer

Uniform, steady, incompressible, along a streamline

Answer

Steady, density being pressure dependent, frictionless

Answer

None of these

Question 2

$$\frac{{{{	ext{C}}_{	ext{p}}}}}{{{{	ext{C}}_{	ext{v}}}}}$$ is termed as

Accepted Answer

Adiabatic constant

Answer

Mach number

Answer

Weber number

Answer

Prandtl number

Question 3

The equivalent diameter for flow through a rectangular duct of width B and height H is

Accepted Answer

$$\frac{{2{	ext{HB}}}}{{{	ext{H}} + {	ext{B}}}}$$

Answer

$$\frac{{{	ext{HB}}}}{{2\left( {{	ext{H}} + {	ext{B}}} ight)}}$$

Answer

$$\frac{{{	ext{HB}}}}{{{	ext{H}} + {	ext{B}}}}$$

Answer

$$\frac{{4{	ext{HB}}}}{{{	ext{H}} + {	ext{B}}}}$$

Question 4

As the velocity V and thus the Reynolds number of a flow past a sphere increases from very low value, the drag force for Re << 1

Accepted Answer

Increases linearly with V

Answer

Decreases linearly with V

Answer

Decreases as V2

Answer

None of these

Question 5

Delivery of insufficient quantity of liquid by a pump may be caused by

Accepted Answer

All of the above

Answer

Air leak in the inlet

Answer

Low rpm

Answer

Too high a lift

Question 6

Design of the casing of centrifugal pump should be such as to minimise the

Accepted Answer

Loss of kinetic head

Answer

Back flow through impeller

Answer

Loss of static head

Answer

None of these

Question 7

A lubricant 100 times more viscous than water would have a viscosity (in Pa.s)

Accepted Answer

0.1

Answer

0.01

Answer

1

Answer

10

Question 8

The bulk modulus of elasticity of a liquid

Accepted Answer

Increases with pressure

Answer

Is zero for incompressible liquid

Answer

Decreases with pressure

Answer

Is independent of temperature & pressure

Question 9

For the transfer of solution of thick slurry, the pump used is a __________ pump.

Accepted Answer

Diaphragm

Answer

Reciprocating

Answer

Gear

Answer

Centrifugal