Different types of pressure

Fluid pressure -:  Pressure is transmitted with equal intensity in all directions and act normal to any plane is known as fluid pressure .

Difference in pressure between any two points at different level in a liquid is equal to = unit weight of liquid × difference in elevation. 

Gauge pressure -: It is equal to unit weight of the liquid multiplied by the height of the desired point above free surface . Gauge pressure represents pressure above atmospheric pressure. 

Bar pressure -: Gauge pressure in bar is generally obtained by dividing the gauge pressure in Pascal Z by 10^5 .

Pressure head-: Pressure head 'h' represent the height of a volumn of homogeneous fluid that will produce a given intensity of the pressure   ( h = p / ρg ) .

Property of a system

Property represents any observable chara-cteristics of the system.  Property of a system depends only on its state , irrespective of how that state was attained. 

Intensive property -: If a property of  a system does not depend upon it's mass , it is intensive property. For example,  pressure, temperature, density,  etc .

Extensive property -: when the property of any system is depend upon the mass it is called extensive property. For example enthalpy , volume, etc .

 

If a given quantity depend on two para-meters is connected such that these para-meters are connected by a line path , then the quantity is not a property . if an given quantity is an exact differential,  it is pro-perty ,otherwise no .

Free energy and free Enthalpy

Free energy -: Free energy ( or Helmholtz function) is defined as  f = u - Ts .

It is equal to the work during a constant- volume isothermal reversible nonflow process .

Free Enthalpy -: Free enthalpy ( or Gibbs function ) is defined as  g = h - Ts

Where , u = internal energy  h = enthalpy ,      T = temperature, s = entropy 

Gibbs function is of particular importance in processes where chemical changes occur. For reversible isothermal steady flow pro-cesses or for reversible constant- pressure isothermal nonflow processes , change in free energy is equal to net work .

Fluid mechanics MCQ-07

Q.1 Gas is a ______ fluid. 

A. Compressible 

B. Non - compressible 

C. Viscous 

D. Non- viscous 

Ans-: A

Q.2 The ratio of the mass of a body to the mass of an equal volume of a substance taken as a standard known as ___.

A. Kinematic viscosity 

B. Relative density 

C. Density

D. Viscosity 

Ans-:B

Q.3 The rise or fall of a liquid in a capillary tube caused by the surface tension called ?

A. Rise of liquid 

B. Fall of liquid 

C. Capillarity 

D. A+B

Ans-: C

Q.4 The fluid such as air for which the density is not a single-valued function of the pressure is known as ?

A. Barotropic fluid 

B. Nonbarotropic fluid 

C. Real fluid 

D. Perfect fluid 

Ans-:B

Q.5 Buoyant force is equal to _____.

A. Force exerted by body

B. Volume of liquid displaced 

C. Force exerted in body

D. Weight of the body 

Ans-: B

Q.6 Stanton tube is used to measure which of the following?

A. Shear strain

B. Shear stress in fluid 

C. Shear strain in fluid 

D. Pressure of fluid 

Ans-: B

Q.7 What is the density of air ?

A. 11.2 kg/m^-3

B. 1.24 kg/m^3

C. 1.24 kg/m^-3

D.  12.4 kg/m^3

Ans-: C

Q.8 Whether stream function exists for which type of flow?

A. Uniform flow 

B. One dimensional flow 

C. Turbulent flow 

D. Two dimensional flow 

Ans-: D

Q.9 What is the value of density of mercury?

A. 1360 kg/m^-3

B. 13600 kg/m ^-3

C. 14000 kg/m^3

D. 13560 kg/m^-3

Ans-: B

Q.10 The square root of ratio inertia force to gravity force is called ?

A. Real number

B. Froude number

C. Reynolds number 

D. None of these 

Ans-: B

Q.11 When specific mass flow is not able to take place in a pipe line us called ?

A. More pressure in pipe line 

B. Choking in pipe line 

C. Disturbance in flow

D  None of these 

Ans-: B

Q.12 Maning's formula is used to measure?

A. Viscosity of fluid

B. Velocity if fluid in pipe 

C. Pressure of fluid in a pipe 

D. Surface tension 

Ans-: B

Q.13 Velocity potential is which type of quantity.

A. Dimensional

B. Scalar

C. Non - scalar

D. None of the above 

Ans-: B

Q.14 In open channel maximum velocity occurs at ______.

A. Center of the channel 

B. Top of the channel

C. Near Bottom of the channel 

D. First point of the channel 

Ans-: C

Q.15 Velocity is zero at which point ?

A. Stagnation point 

B. Triple point 

C. Critical point

D. None of the above 

Ans-: A

Fluid mechanics MCQ-06

Q.1 Center of pressure on a inclined plane is ________ .

A. Above the centroid

B. Below the centroid 

C. At the centroid 

D. None of these 

Ans-: B

Q.2 The unit of dynamic viscosity is ___.

A. M^2 per second 

B. Newton sec per m^2

C. Newton sec per m^3

D. Kg sec / meter

Q.3 Spherical shape of the rain drop are due to ___.

A. Surface tension 

B. Viscosity 

C. Density 

D. None of the above 

Ans-: A

Q.4 The inside and outside pressure diffe-rence between inside and outside of water drop is ______.

A. P = T/r

B. P = 2T/r

C. P = T×r

D. 0

Ans-: B

Q.5 Which devise is used to measure very low pressure?

A. Thermometer 

B. Manometer

C. Piezometer

D. None of these 

Ans-: C

Q.6 Surface tension of water at 20°C is ___.

A. 60.71

B. 60.61

C. 52.23

D. 79.61

Ans-: A

Q.7 Due to balance of the body weight and the buoyancy force a floating body ______.

A. Submerged in water 

B. Partially submerged 

C. Floating 

D. None of these 

Ans-: B

Q.8 General energy equation holds for which type of flow?

A. Laminar flow 

B. Uniform flow 

C. Non- uniform flow 

D. Steady flow 

Ans-: C

Q.9 Hydraulic grade line may be above or below the centre line of conduit.

A. Yes 

B. No 

C. At specific pressure 

D. None of these 

Ans-: A

Q.10 During the opening of a valve in a pipe line ,the flow is ______.

A. Steady 

B. Unsteady 

C. Uniform 

D. Turbulent 

Ans-: B

Fluid mechanics MCQ -05

Q.1 For which type of flow Bernoulli's theo-rem is applicable?

A. Turbulent flow 

B. Laminar flow 

C. Perfect incompressible fluid flowing in a continuous stream

D. Normal flow

Ans-: C

Q.2 Velocity of flow in open channel is determined by which equation?

A. Chezy's equation 

B. Bernoulli equation 

C. Motion equation 

D. None of these 

Ans-: A

Q.3 The magnitude of the water hammer is depend on the _______ .

A. Rate of stoppage of flow

B. Length of the pipe

C. Elastic properties of pipe material 

D. All of the above 

Ans -: D

Q.4 At the center of the pipe velocity of fluid particles is _____.

A. Zero

B. Maximum 

C. Minimum 

D. One

Ans-: B

Q.5 100 kN/m^2 is equal to _____ .

A. 100 mm of water column

B. 10 mm of water column

C. 20 mm of water column 

D. 200 mm of water column

Ans-: B

Q.6 The flow in venturiflume take place at ___.

A. Vacuum 

B. Atmospheric pressure 

C. High temperature 

D. High pressure 

Ans-: B

Q.7 Bernoulli theorem deals with the conser-vation of hydraulic pressure .

A. Yes 

B. No 

C. At high pressure 

C. At 0° C 

Ans-: A

Q.8 The volume of water which flows thro-ugh a section of a channel per second is known as __.

A. Flow rate

B. Discharge 

C. Stream flow 

D. None of these 

Ans-: B

Q.9 The pattern obtained by the intersection of stream lines and potential lines is called _.

A. Flow pattern

B. Flow design

C. Flow net

D. Flow rate 

Ans-: C

Q.10 The force exerted on a body by a static fluid in which it is submerged or floating called ______ force .

A. Buoyant force

B. Drag force

C. Impact load 

D. Submerged force

Ans-: A

Fluid mechanics MCQ-04

Q.1 which instrument is used to measure flow ?

A. Thermometer 

B. Rotameter

C. Raynold's meter

D. Barometer

Ans-: B

Q.2 Hydraulic jump is the example of which type of flow ?

A. Uniform flow 

B. Steady flow 

C. Non- uniform flow 

D. Turbulent flow 

Ans-: C

Q.3 Any obstruction of a stream flow over which water flows can be called ___.

A. Weir

B. Spillway

C. Water hammer

D. None of these 

Ans-: A

Q.4 water hammer is caused due to sudden stoppage of ____ .

A. Water contain in a tank

B. Water flow in a pipe 

C. Water flow through open channel 

D. All of the above 

Ans-: B

Q.5 _____ are used to relieve the pipe line of excessive pressure. 

A. Dam

B. Surge tank 

C. Hydraulic dam

D. None of these 

Ans-: B

Q.6 which device is used for measuring the rate of flow of a liquid through a small channel?

A. Notch

B. Rotameter 

C. Manometer

D. NOT

Ans-: A

Q.7 which of the following is measured by the pitot tube?

A. Pressure 

B. Flow

C. Discharge 

D. Velocity 

Ans-: D

Q.8 the upper surface of the weir over which water flows ______.

A. Vein

B. Sill

C. Nappe

D. Weir top surface 

Ans-: B

Q.9 specific gravity of fluid is determined by 

A. Hydrometer

B. Rotameter 

C. Manometer

D. None of these 

Ans-: A

Q.10 An idel fluid is __.

A. Frictionless 

B. Incompressible 

C. Very viscous 

D. A+B

Ans-: D