Fluid Mechanics

11. A large Roynold number is indication of

1. smooth and streamline flow
2. laminar flow
3. steady flow
4. turbulent flow
5. highly turbulent flow.

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12. A liquid compressed in cylinder has a volume of 0.04 m3 at 50 kg/cm2 and a volume of 0.039 m3 at 150 kg/cm2. The bulk modulus of elasticity of liquid is

1. 400 kg/cm2
2. 4000 kg/cm2
3. 40 x 105 kg/cm2
4. 40 x 106 kg/cm2
5. none of the above.

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13. A liquid would wet the solid, if adhesion forces as compared to cohesion forces are

1. less
2. more
3. equal
4. less at low temperature and more at high temperature
5. there is no such criterion.

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14. A metal with specific gravity of o floating in a fluid of same specific gravity a will

1. sink to bottom
2. float over fluid
3. partly immersed
4. be fully immersed with top surface at fluid surface
5. none of the above.

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15. A model of a reservior is drained in 4 mts by opening the sluice gate. The model scale is 1: 225. How long should it take to empty the prototype ?

1. 900 minutes
2. 4 minutes
3. 4 x (225)3/2 minutes
4. 4 (225)1/3 minutes
5. 4 x V225 minutes.

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16. A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity of 5 m/sec. What model scale has been used ?

1. 1 : 5
2. 1 : 2.5
3. 1 :25
4. 1:V5"
5. 1 : 53/2

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17. A one dimensional flow is one which

1. is uniform flow
2. is steady uniform flow
3. takes place in straight lines
4. involves zero transverse component of flow
5. takes place in one dimension.

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18. A perfect gas

1. has constant viscosity
2. has zero viscosity
3. is in compressible
4. is of theoretical interest
5. none of the above.

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19. A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?

1. the metal piece will simply float over the mercury
2. the metal piece will be immersed in mercury by half
3. whole of the metal piece will be immersed with its top surface just at mercury level
4. metal piece will sink to the bottom
5. none of the above.

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20. A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury ?

1. 0.5
2. 0.4
3. 0.515
4. 0.5
5. none of the above.

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