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This section includes 88 Mcqs, each offering curated multiple-choice questions to sharpen your Fluid Mechanics knowledge and support exam preparation. Choose a topic below to get started.
51. |
An object weighs 60 gm in air, 50 gm in water and 40 gm in oil. Then the specific gravity of the oil will be _____. |
A. | 0.25 |
B. | 1 |
C. | 1.5 |
D. | 2 |
Answer» E. | |
52. |
A liquid is compressed in a cylinder from a volume of 0.02 m3 at 200 N/m2 pressure to a volume of 0.01 m3 at 400 N/m2 pressure. The bulk modulus of elasticity of the liquid is |
A. | 500 N/m2 |
B. | 1000 N/m2 |
C. | 400 N/m2 |
D. | 600 N/m2 |
Answer» D. 600 N/m2 | |
53. |
At constant temperature, the fluid whose viscosity does not change with the rate of deformation, is called: |
A. | Read fluid |
B. | Non-Newtonian fluid |
C. | Ideal fluid |
D. | Newtonian fluid |
Answer» E. | |
54. |
If for a fluid in motion, pressure at a point is same in all direction, then the fluid is |
A. | A real Fluid |
B. | A Newtonian Fluid |
C. | An Ideal Fluid |
D. | A non-Newtonian Fluid |
Answer» D. A non-Newtonian Fluid | |
55. |
Match List-I with List-II and choose the correct answer from the options given below List-I(Fluid property) List-II(Flow Phenomenon)A. Compressibilitya. The flow of real fluid past a tiny sphere B. Gravityb. CavitationC. Viscosityc. Hydraulic jumpD. Vapour pressure d. Flight of supersonic aircraft |
A. | A - c, B - d, C - b, D - a |
B. | A - c, B - d, C - a, D - b |
C. | A - d, B - c, C - a, D - b |
D. | A - d, B - c, C - b, D - a |
Answer» D. A - d, B - c, C - b, D - a | |
56. |
1.0 N/m2 is equal to: |
A. | 1.0 Pa |
B. | 1.0 kPa |
C. | 1.0 MPa |
D. | 1.0 bar |
Answer» B. 1.0 kPa | |
57. |
In the phenomenon of Cavitation, the characteristic fluid property involved is; |
A. | Surface tension |
B. | Viscosity |
C. | Bulk modulus of elasticity |
D. | Vapour pressure |
Answer» E. | |
58. |
In Red Wood Viscometer ______. |
A. | Absolute value of viscosity is determined |
B. | Part of the head of fluid is utilised in overcoming friction |
C. | Fluid discharges through orifice with negligible velocity |
D. | Comparison of viscosity is done |
Answer» B. Part of the head of fluid is utilised in overcoming friction | |
59. |
A Newtonian fluid is one which |
A. | is viscous but incompressible |
B. | has a linear relationship between the shear stress and the rate of angular deflection |
C. | exhibits an increase in viscosity with increasing rate of deformation |
D. | exhibits an decrease in viscosity with increasing rate of deformation |
Answer» C. exhibits an increase in viscosity with increasing rate of deformation | |
60. |
A steam turbine is supplied with steam at a pressure of 20 bar gauge. After expansion in the steam turbine, the steam passes to condenser which is maintained at a vacuum of 250 mm of mercury by means of pumps. The inlet and exhaust steam pressures will be nearly |
A. | 2101 kPa and 68 kPa |
B. | 2430 kPa and 78 kPa |
C. | 2101 kPa and 78 kPa |
D. | 2430 kPa and 68 kPa |
Answer» B. 2430 kPa and 78 kPa | |
61. |
Pseudo-plastic is a fluid for which |
A. | Dynamic viscosity decreases as the rate of shear increases |
B. | Newton’s law of viscosity holds good |
C. | Dynamic viscosity increases as the rate of shear increases |
D. | Dynamic viscosity increases with the time for which shearing forces are applied |
Answer» B. Newton’s law of viscosity holds good | |
62. |
A plate weighting 150 N and measuring 0.8 m × 0.8 m just slides down an inclined plane over an oil film of 1.2 mm thickness for an inclination of 30° and velocity of 0.2 m/s. Then the viscosity of the oil used is |
A. | 0.3 Ns/m2 |
B. | 0.4 Ns/m2 |
C. | 0.5 Ns/m2 |
D. | 0.7 Ns/m2 |
Answer» E. | |
63. |
Match List-I (Fluid properties) with List-II (Related terms) and select the correct answer using the given lists:List-IList-IIA. Capillaritya. CavitationB. Vapour pressureb. Density of waterC. Viscosityc. Shear forcesD. Specific gravityd. Surface tension |
A. | A-a, B-d, C-b, D-c |
B. | A-a, B-d, C-c, D-b |
C. | A-d, B-a, C-b, D-c |
D. | A-d, B-a, C-c, D-b |
Answer» E. | |
64. |
Alcohol is used as manometers because |
A. | it has low vapor pressure |
B. | it is clearly visible |
C. | it has low surface tension |
D. | it can provide longer column due to low density |
Answer» E. | |
65. |
Dynamic viscosity of water in comparison to mercury is |
A. | Higher |
B. | Lower |
C. | Same |
D. | Unpredictable |
Answer» C. Same | |
66. |
In the figure given above, for the ideal fluid, the curve that is applicable is: |
A. | A |
B. | B |
C. | C |
D. | D |
Answer» B. B | |
67. |
Dynamic viscosity increases with the rate of shear increase for |
A. | dilatant fluid |
B. | pseudoplastic fluid |
C. | rheopectic fluid |
D. | thixotropic fluid |
Answer» B. pseudoplastic fluid | |
68. |
An ideal fluid is one which is: |
A. | non-viscous |
B. | incompressible |
C. | incompressible and non-viscous |
D. | non-viscous and frictionless |
Answer» D. non-viscous and frictionless | |
69. |
Find the correct pair |
A. | Kinematic viscosity – ρ/µ (Density/dynamic viscosity) |
B. | Fluid of zero viscosity – Ideal fluid |
C. | Ideal fluid – kinematic viscosity |
D. | Viscous fluid – Fluid of zero viscosity |
Answer» C. Ideal fluid – kinematic viscosity | |
70. |
If no resistance is encountered by displacement, such a substance is known as _____. |
A. | Fluid |
B. | Water |
C. | Gas |
D. | Ideal Fluid |
Answer» E. | |
71. |
Ideal fluid is one which has no |
A. | Viscosity |
B. | Surface tension |
C. | Both viscosity and surface tension |
D. | None of the options |
Answer» D. None of the options | |
72. |
Poise can also be expressed as |
A. | Dyne-cm/s2 |
B. | Dyne-cm/s |
C. | Dyne-s/cm |
D. | Dyne-s/cm2 |
Answer» E. | |
73. |
Kinematic viscosity is equal to : |
A. | Dynamic viscosity/density |
B. | Dynamic viscosity × density |
C. | Density/dynamic viscosity |
D. | 1/dynamic viscosity × density |
Answer» B. Dynamic viscosity × density | |
74. |
Kinematic viscosity of air at 20°C is given to be 1.6 × 10-5 m2/s. Its kinematic viscosity at 70°C will be approximately |
A. | 2.2 × 10-5 m2/s |
B. | 1.6 × 10-5 m2/s |
C. | 1.2 × 10-5 m2/s |
D. | 3.2 × 10-5 m2/s |
Answer» B. 1.6 × 10-5 m2/s | |
75. |
'Kinematic viscosity' is dimensionally represented as |
A. | \(\frac{T^2}{L}\) |
B. | \(\frac{L^2}{T}\) |
C. | \(\frac{M}{L^2T}\) |
D. | \(\frac{M}{LT}\) |
Answer» C. \(\frac{M}{L^2T}\) | |
76. |
Kinematic viscosity of gases on increase of temperature |
A. | Decreases |
B. | Increases |
C. | Remains the same |
D. | First decreases then increases |
Answer» C. Remains the same | |
77. |
A moving fluid mass may be brought to a static equilibrium position by applying an imaginary inertia force of the same magnitude as that of the accelerating force but in the opposite direction. This statement is called |
A. | Pascal’s law |
B. | Archimedes’ principle |
C. | D’Alembert’s principle |
D. | None of these |
Answer» D. None of these | |
78. |
According to Newton’s law of viscosity, shear stress is: |
A. | directly proportional to the velocity |
B. | inversely proportional to the velocity |
C. | directly proportional to the velocity gradient |
D. | directly proportional to viscosity |
Answer» D. directly proportional to viscosity | |
79. |
One poise is equivalent to: |
A. | 1 kg/m-hr |
B. | 1 gm/cm-sec |
C. | 98 dyne/sec |
D. | 68 kgf-sec/m2 |
Answer» C. 98 dyne/sec | |
80. |
Floating logs of wood tend to move to thy' mid-river reach on the water surface. This is due to |
A. | Least obstruction from the banks |
B. | 2-cell transverse circulation in the flow |
C. | Fastest velocity along the mid-river reach |
D. | Near-symmetry of the isovels across the section is conducive to principle of least work |
Answer» C. Fastest velocity along the mid-river reach | |
81. |
Pick the correct statement about the bulk modulus of elasticity: |
A. | it is a dimensionless number |
B. | it is independent of pressure and viscosity |
C. | it is larger if fluid is more compressible |
D. | it is higher if the fluid is less compressible |
Answer» E. | |
82. |
Bulk modulus of elasticity. |
A. | is independent of temperature |
B. | increases with pressure |
C. | is independent of pressure and viscosity |
D. | is larger when fluid is more compressible |
Answer» C. is independent of pressure and viscosity | |
83. |
A fluid whose shear stress is linearly proportional to the velocity gradient in the direction perpendicular to the plane of shear is called as _______. |
A. | Friction fluid |
B. | Stress fluid |
C. | Newtonian fluid |
D. | Cartesian fluid |
Answer» D. Cartesian fluid | |
84. |
_________ is NOT a property of fluid. |
A. | Specific weight |
B. | Area |
C. | Specific volume |
D. | Mass density |
Answer» C. Specific volume | |
85. |
In a Newtonian fluid, the shear stress |
A. | is inversely proportional to the strain |
B. | is directly proportional to rate of shear strain |
C. | balances pressure |
D. | balances inertia stress |
Answer» C. balances pressure | |
86. |
A liquid compressed in a cylinder has a volume of 0.04 m3 at 100 kg/cm2 and a volume of 0.039 m3 at 200 kg/cm2. The bulk modulus of elasticity of liquid is |
A. | 4000 kg/cm2 |
B. | 400 kg/cm2 |
C. | 40 × 105 kg/cm2 |
D. | 40 × 106 kg/cm2 |
Answer» B. 400 kg/cm2 | |
87. |
If the specific gravity of oil is 0.7, then its density in kg/m3 will be ______ |
A. | 70 |
B. | 700 |
C. | 7 |
D. | 7000 |
Answer» C. 7 | |
88. |
An iceberg floats in sea water with 14% of its volume projecting above the sea surface. If the specific weight of sea water is 10400 N/m3, determine the specific weight of the iceberg (in N/m3 units). |
A. | 9125 |
B. | 8836 |
C. | 8314 |
D. | 8944 |
Answer» E. | |