Mechanical Properties of Fluids Mock Test – Class 11 Physics

1. In a liquid at rest, two points lie in the same horizontal level. If the liquid is connected and has uniform density, the pressures at the two points are

2. In a simple description of surface tension, the free surface of a liquid behaves somewhat like

3. Assertion: Two open vessels of different shapes filled with the same liquid to the same height have the same pressure at their bases if the base points are at the same depth.
Reason: Hydrostatic pressure due to a liquid at rest is given by .

4. Two vessels contain water to the same height. Vessel P has base area , while vessel Q has base area . The gauge pressure at the base and the force on the base satisfy

5. If the viscosity of the fluid is doubled while all other quantities in remain the same, the terminal velocity becomes

6. A liquid flows through a pipe at . A student describes it as definitely smooth laminar flow because the number is positive. The better response is that

7. A vertical rectangular plate of width is fully submerged with its top edge at the free surface and its bottom edge at depth . In water with and , the average gauge pressure and total force on the plate are

8. Assertion: Two streamlines in steady flow cannot intersect.
Reason: If two streamlines intersected, the fluid velocity at the intersection would have two different directions.

9. A fluid layer of area has velocity gradient . If the coefficient of viscosity is , the tangential viscous force is

10. Assertion: A gas is usually more compressible than a liquid.
Reason: Gas molecules are generally much farther apart than molecules in a liquid.

11. A liquid surface has surface tension . The force acting along a line of length on the surface is

12. In a fluid at rest, a small imaginary surface is placed at a point first horizontally and then vertically. The pressure value at that point is

13. In applying to a liquid emerging from a tank, represents the

14. Pressure is introduced in fluid mechanics as

15. The SI unit of surface tension is

16. Consider the following statements about hydrostatic pressure.
Statement I: The pressure contribution due to a liquid column increases with liquid density.
Statement II: The pressure contribution due to a liquid column increases with vertical depth.
Statement III: For , is measured from the bottom of the container upward.

17. Consider the following statements about surface tension and surface energy.
Statement I: Surface tension may be treated as force per unit length.
Statement II: Surface tension may be treated as surface energy per unit area.
Statement III: Surface tension has the same unit as pressure.

18. In the relation for a liquid at rest, represents

19. A liquid jet leaves a small hole in a tank horizontally. The hole is at depth below the free surface and height above the ground. If the liquid level is lowered while the hole height above the ground remains unchanged, the horizontal range of the jet

20. Consider the following statements about a simple mercury barometer.
Statement I: The mercury column height represents atmospheric pressure through .
Statement II: The height is measured vertically.
Statement III: For the same atmospheric pressure, a less dense barometer liquid would need a smaller height.

21. A capillary tube is long enough for water to rise , but only of the tube is above the outside water level. The most suitable conclusion is that

22. Use the arrangement described below.

What can be said about the pressures at P and Q?

23. An ideal fluid used in elementary Bernoulli and continuity discussions is usually taken to be

24. A data set for a Newtonian fluid gives shear stress on the vertical axis and velocity gradient on the horizontal axis. If the straight-line slope is , the coefficient of viscosity is

25. In the terminal velocity formula , a sphere will not fall downward through the fluid if

26. Use the graph description below.

The slope of the graph represents

27. Pascal’s law states that when pressure is applied to an enclosed fluid, the pressure is transmitted

28. A point inside an open liquid has gauge pressure . If the atmospheric pressure is ignored while finding absolute pressure, the result will be

29. Use the case below and answer the question.

For an ideal system, the load force on the large piston and its displacement compared with the small piston are

30. A horizontal base and a vertical side wall are both in contact with the same liquid at rest. The main difference in calculating force is that

31. A soap bubble has radius and surface tension . The excess pressure inside the bubble is

32. Study the table and identify the row that uses Archimedes’ principle correctly.

33. A short note says that in elementary fluid flow represents the volume of fluid crossing a section per unit time. Its SI unit should be

34. The dimensional formula of coefficient of viscosity is

35. A narrow pipe carries a liquid. When the flow speed is increased greatly, the motion changes from smooth layers to irregular motion with eddies. This change is from

36. A pipe of area carries water at speed . The pipe narrows to area . For steady incompressible flow, the speed in the narrow section is

37. A liquid rises to height in a capillary tube. If the same liquid rises to height in another tube of the same material, the radius of the second tube is

38. Study the table and choose the row that contains an incorrect statement.

39. Two soap bubbles of the same liquid have radii and . They are connected by a narrow tube. Air tends to flow

40. A stone weighs in air and when fully immersed in water. The buoyant force on the stone is

41. In the capillary formula , a liquid rises in the tube when

42. Assertion: Water generally rises near the wall of a clean glass capillary.
Reason: Water wets glass and has an acute angle of contact with it.

43. The angle of contact is the angle between the tangent to the liquid surface and the solid surface, measured

44. A closed-end manometer has a near-vacuum above the liquid in the closed arm. If the pressure of a gas connected to the other arm supports a liquid column difference , the gas pressure is approximately

45. A student checks the capillary formula . Which unit result should the right-hand side have?

46. Use the arrangement described below.

The water level in the pressure tube at Q is expected to be

47. A formula is proposed for capillary rise as , with no tube radius. A dimensional check shows that the right-hand side has unit

48. A pipe flow has Reynolds number . The same fluid in the same pipe is made to flow at three times the speed. The new Reynolds number and likely change are

49. A diver moves from depth to depth in water. Take and . The increase in gauge pressure is

50. A small water drop and a large water drop are compared in air. The small drop is more nearly spherical mainly because