## Thursday, 5 March 2015

### Fluid Mechanics & Machineries Very Important Questions

Fluid Mechanics & Machineries Very Important Questions

Fluid Mechanics & Machineries :
Module –I (Introduction) :
1. Define fluid? :
A fluid is a substance having a property to flow easily.

Example : liquid, vapour, gas.

2. Define fluid mechanics? :
Fluid mechanics is a branch of science which deals with property and behaviour of fluids at rest and in motion.

3.Define fluid statics? :
The study of fluids at rest is called fluid statics .

4.Define fluid kinematics? :
The study of fluids in motion where pressure forces are not considered is called fluid kinematics.

5.What is the SI unit of density ? :
The SI unit of density is kg/m3.

Example : Density of water is 1000 kg/m3.

6.Define specific volume? :
It is the ratio of volume to the mass of a fluid. It is denoted by .Its unit is m3/kg.
= volume of fluid/Mass of fluid
=V/m m3/kg

7. Define specific gravity with respect to density? :
It is the ratio of density of a fluid to density of a standard fluid. It is denoted by s.

i.e, s = density of liquid/density of water
s = density of gas/density of air

8.Define viscosity? :
It is defined as the resisting property of liquid to its flow corresponding to its adjacent layers.

9. Which one of the following has high viscosity, (i) water or (ii) lubricating oil? :
Lubricating oil has high viscosity.

10. Define poise ? :
Poise is the other name of unit of viscosity in CGS system which equals dyne-sec/cm2.

11.Give the classification of fluids? :
Classification of fluids are,
(i) Ideal fluid
(ii) Real fluid
(iii) Newtonian fluid
(iv) Non Newtonian fluid
(v) Ideal plastic fluid.

12. What is real fluid? :
A fluid which has viscosity is a real fluid. All fluid in practice are real fluids.

13.What is non Newtonian fluid? :
A real fluid in which shear stress is not proportional to rate of shear strain.

14.What is compressibility? :
Compressibility is the property of fluid which undergoes change in volume under various pressure conditions.

15. Define compressible fluid? :
A liquid is considered to a compressible fluid only when there is a change in volume of liquid that occurs under large pressure variation .

16. Define compressibility? :
It is also defined of reciprocal of bulk modulus of elasticity (k).

i.e,
compressibility = 1/k .
k= compressive stress / volumetric strain

17.Define capillarity? :
It is the phenomenon of rise or fall of liquid surface relative to out side liquid surface

18.Give the types of gas laws? :
The types of gas laws are,
(i) Boyles law
(ii) Charles law

19. Give some properties of fluid? :
Some properties of fluids are density, specific weight, viscosity, surface tension and capillarity

20. Define fluid dynamics? :
The study of fluid in motion where pressure forces are considered is called as fluid dynamics.