55B.docx

Sub: Water Resources Engineering

Topic : Fluid Mechanics & Hydraulics

MODULE- 55B Properties of fluids, 1.

Water has the surface tension of 0.4 N/ m. in a 3mm diameter vertical tube, if the liquid rises 6mm above the liquid outside the tube, calculate the wetting angle. a) 73. b) 83. c) 93. d)

2.

6.

The velocity distribution for flow over a plate is given by μ= 0.9 y where μ is the velocity in m/s. at a distance 4 m above the plate. If the dynamic viscosity of the flied is 0.9 ⁄

at 0.2 m from the boundary? a) 0.9

c) 2.25 ⁄ d) 0.09 ⁄ 7.

Given m= 80kg and a= 10m/ . Find the force.

4.

The surface tension of water at C is 75× N/m. The difference in the water surfaces within and outside an open ended capillary tube of 1 mm internal bore inserted at the water surface would be 5 mm 10 mm 15 mm 20 mm

⁄

b) 1.8 ⁄

A reservoir of oil has a mass of 825kg. The reservoir has a volume of 0.917 . What are the density, specific weight and specific gravity of oil?

3.

, then what is the shear stress

Which one the following expression the height of rise or fall of a liquid in a capillary tube? a)

a) b) c) d) 5.

Oil (μ= 044

- 3, P= 888

c) d) Where w = .wt.of liquid =Angle of contact = Surface tension 8. Kinematic viscosity [V] is measured is a) μ * μ b) c)

) is filled

a.

in the space between two parallel plates which are 18 mm apart. The upper plate is moving at a velocity of 4 m/s. what is the shear stress on the plate 97.8

b.

48. 8

c.

79.8

d.

87.9

JH ACADEMY

b)

μ

d) None. 9.

Surface tension in fluids is measured in a) MPa ⁄ b) c)

μ

d) N – mm 10.

Pascal in SI units is a unit of

Page 1

Sub: Water Resources Engineering a) b) c) d) 11.

12.

13.

Topic : Fluid Mechanics & Hydraulics

Force Stress Mass Length.

As the temperature is increased, the viscosity of water a) Increases b) Decreases c) Remains constant d) Varies with pressure. Cavitation is caused by a) Low pressure b) High pressure c) Low velocity d) High velocity The dynamic viscosity of a fluid is 0.139 kgf-sec/ . If the specific gravity of fluid is 0.95 its kinematic viscosity is a) 0.1463 ec b) 0.001435 ec c) 0.000146 ec d) 0.5 ec

droplet of water 6× is a) 0.01 kg/c b) 0.04 kg/c c) 0.005 kg/c d) 0.05 kg/c 18.

An ideal fluid is a) One which obeys newton’s law of viscosity b) Frictionless and in compressible. c) Very viscous d) Frictionless and compressible.

19.

Bulk modulus is ratio of a) Stress and strain b) Shear stress and strain c) Stress and volumetric strain d) Lateral strain and longitudinal strain.

20.

The viscosity of gases a) Decreases with temperature b) Increases with temperature c) Is independent of temperature d) None of the above.

21. 14.

Coefficient of dimensions of

viscosity

has

the

a) b) c) d) 15.

16.

17.

a) b) c) d)

Stoke is the unit of Surface tension Dynamic viscosity Kinematic viscosity Density

a) b) c) d)

Study of fluid at rest, is known as Kinematics Dynamics Statics None

22.

An iron needle placed on water surface in a tank floats on the water although its weight is more. This is due to a) Specific gravity b) Cohesion c) Compressibility d) Surface tension The height of water in capillary tube a) Increases with increase in diameters b) Increases with decrease in diameter c) Decreases with an increase in surface tension d) Increases with an increase in specific weight. The intensity of pressure developed by surface tension of 0.0075 kg/m in a

JH ACADEMY

mm diameter

23.

For a fluid jet, the surface tension ( ) and difference of pressure (∆ ) are related as a) ∆ = b) ∆ = c)

∆ =

d) ∆ = The angle of contact θ between mercury and glass tube in case of capillary depression is

24.

a) b)

Page 2

Sub: Water Resources Engineering

Topic : Fluid Mechanics & Hydraulics

c) d) 25.

27.

At a certain point in castor oil the shear stress is 0.216 N/ and a velocity gradient 0.216 . If the mass density of castor oil is 959.42 kg/ find kinematic viscosity in /s a) 1.042× b) 1.042× c) 1.042× d) None If a certain liquid has viscosity 4.9× kf-f-sec/ and kinematic viscosity 3.49× stokes, what is specific gravity a) 1.38 b) 1.28 c) 1.18 d) 0.98

28.

31.

Kinematic viscosity of air at C is given to be 1.6× . its kinematic viscosity at C will be vary approximately. a) 2.2× b) 1.6× c) 1.2× d) 3.2×

32.

a) b) c) d)

33.

For a newton fluid a) Shear stress is propotional to shear strain b) Rate of shear stress is propotional to shear strain c) Shear stress is propotional to shear strain d) Rate of shear stress is proportional to rate of shear strain.

34.

The dimensions of surface tension is a) N/ b) J/m c) J/ d) W/m

35.

What are the unit viscosity of a fixed fluid termed poise equivalent to a) dyne/c b) gm.s/cm c) dyne-s/c d) gm-cm/SA

36.

What are the dimensions of kinematic viscosity of a fluid a) L b) c) M

()

4.42× 4.42× 4.42× 4.42

A glass tube 0.25 mm diameter contains mercury column with air above the mercury at C. the surface tension of mercury in contact with air is 0.051 kgf/ m what will be the capillary depression of the mecury if angle of contact θ= and sp.gr. of mercury = 13.6 a) 3.86 cm b) 4.86 cm c) 2.86 cm d) 2 cm

JH ACADEMY

The dimensions of surface tension is a) b) c) d)

If the pressure of a liquid is increased from 75 kg (f)/c , the volume of the liquid decreases by 0.147%. find bulk modulus of elasticity of liquid in

29.

If a certain liquid has viscosity of 0.048 Poise and kinematic viscosity 3.5× stokes. What is its specific gravity a) 1.371 b) 1.271 c) 1.171 d) 0.97

A plate 0.0254 mm distant from a fixed plate moves at 61 cm/sec and requires a force of 0.2 kgf/ to maintain this speed. Dynamic viscosity of fluid is a) 8.328× gf b) 8.328× c) 8.328× d) None

26.

30.

Page 3

Sub: Water Resources Engineering

Topic : Fluid Mechanics & Hydraulics

d) M 37.

38.

An oil of specific gravity 0.9 has viscosity of 0.28 stokes at C. what will be its viscosity of 0.28 stokes at C. what will be its viscosity in Ns/ ? a) 0.2520 b) 0.0311 c) 0.0252 d) 0.0206

40.

41.

43.

Match list-I (Rheological equation) with List-II (type of fluid) and select the correct answer. List-I A. = μ ( )

=

B. = μ ( )

a) μ

C. = μ ( )

b) μ

D. =

c) μ ( )

List-II 1. Bingham plastic 2. Dilatants fluid 3. Newtonian fluid 4. Preudo-Plastic fluid A B C D a) 3 2 4 1 b) 4 1 2 3 c) 3 4 2 1 d) 4 2 1 3

⁄

The capillary rise at C in clean glass tube of 1 mm diameter containing water approximately a) 15 mm b) 50 mm c) 20 mm d) 30 mm

44.

Surface tension is due to a) Viscous forces b) Cohesion c) Adhesion d) The difference between adhesion and cohesion

JH ACADEMY

=

A) ideal fluid B) Newtonian fluid μ C) ⁄

1. Viscosity does not change with rate of deformation 2. Fluid of zero viscosity 3. Dynamic viscosity 4. Capillary depression 5. Kinematic viscosity 6. Capillar rise A B C D a) 1 2 4 6 b) 1 2 3 4 c) 2 1 3 6 d) 2 1 5 4

Decrease in temperature, in general results in a) An increase in viscosities of both gases and liquids b) A decrease in the viscosities of both liquids and gases c) An increase in the viscosity of liquids and decrease in that of gases d) A decrease in the viscosity of liquids and increase in that of gases. If the relationship between the shear tre and the rate of shear strain

+μ ( )

D) Mercury in glass

45. 42.

= μ ( ) then

the fluid with exponent n >1 is known as which one of the following. a) Bingham plastic b) Dilatants fluid c) Newtonian fluid d) Pseudo plastic fluid

In a Newton fluid, laminar flow between two parallel plates, the ratio ( ) between the shear stress and rate of shear strain is given by

d) μ ( ) 39.

i expre ed a

Assertion (A): Blood is a Newtonian fluid.

Page 4

Sub: Water Resources Engineering Reason(R): The rate of strain varies non-linearly with shear stress for blood. a) Both A and R are individually true and R is the correct explanation of A b) Both A and R are individually true but R is not the correct explanation of A c) A is true but R is false d) A is false but R is true

46.

What is the capillary rise in a narrow two dimensional silt of width w? a) Half that in a capillary tube of diameter tube w b) Two third of that in a capillary tube of diameter w c) One third of that in a capillary tube of diameter w d) One- fourth of that in a capillary tube of diameter w

47.

When the pressure on a given mass of liquid is increased from 3.0 MPa, the density of the liquid increases from 500 kg/ to 501 kg/ . What is the average value of bulk modulus of the liquid over the given pressure range? a) 700 MPa b) 600 MPa c) 500 MPa d) 250 MPa

48.

Which property of mercury is the main reason for use in barometers? a) Low vapour pressure b) High density c) Viscosity d) Cohesion

49.

Which one of the following sets of conditions clearly apply to an ideal fluid? a) Viscous and compressible b) Non-viscous- incompressible c) Non-viscous and compressible d) Viscous and incompressible.

JH ACADEMY

Topic : Fluid Mechanics & Hydraulics 50.

Fluids that require a gradually shear stress to maintain a constant strain rate are known as a) Rhedo pectic fluids b) Thixotropy fluids c) Pseudo plastic fluids d) Newtonian fluid.

Page 5