Mechanical Properties of Fluids Mock Test – Class 11 Physics

1. A block displaces of oil of density . If , the buoyant force on the block is

2. Study the table and identify the correct Poiseuille-law dependence.

3. The ideal derivation of from Bernoulli’s equation assumes that

4. A solid of density and volume is fully immersed in water of density . Taking , the net force on it just after release is

5. Study the table and identify the correct row.

6. Torricelli’s theorem gives the speed of efflux from a small hole in a tank as

7. 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

8. Match the basic quantities with their SI units.

9. Study the table and identify the correct wetting pair.

10. Consider the following statements about steady and unsteady flow.
Statement I: In steady flow, velocity at a fixed point remains constant with time.
Statement II: In unsteady flow, velocity at a fixed point may change with time.
Statement III: Steady flow requires the velocity to be the same at all points in the fluid.

11. A barometer is taken from sea level to a high mountain. The mercury column becomes shorter. The best explanation is that

12. 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

13. Two small holes in a tank are at depths and below the free surface, where the total water height is . If both jets fall to the same ground level, their horizontal ranges are

14. Laminar flow is best described as fluid motion in which

15. The role of density in many fluid-mechanics formulas is best shown by the fact that a denser fluid generally

16. A water tank open to air has . At one point, the absolute pressure is . Taking and , the depth of the point is

17. Oil rises through the wick of a lamp mainly due to

18. Study the table and identify the row that gives the most suitable first meaning.

19. Match the hydraulic-system quantities with their correct roles.

20. A graph is plotted between Stokes drag and speed for the same small sphere in the same fluid. In the range where Stokes’ law is valid, the graph is

21. Detergent is added to water on which small insects were able to stand. The insects may sink more easily because detergent

22. Water flows horizontally through a pipe of area at speed . The pipe narrows to . If and viscosity is neglected, the pressure drop from the wide section to the narrow section is

23. An open-tube manometer contains mercury of density . The mercury level difference is , with the connected gas side lower. Take . The gauge pressure of the gas is

24. A graph is plotted between volume flow rate and pressure difference for laminar flow through a fixed capillary tube. According to Poiseuille’s law, the graph is

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

26. A fluid is treated as incompressible in a simple calculation when its

27. Consider the following statements about the hydrostatic paradox.
Statement I: Same liquid height can give the same base pressure in vessels of different shapes.
Statement II: The total force on a horizontal base depends on the base area.
Statement III: Base pressure is decided by the total volume of liquid in the vessel.

28. The hydrostatic paradox refers to the idea that the pressure at the base of a liquid-filled vessel depends on

29. A horizontal base of area is under a uniform gauge pressure of . The force exerted by the liquid on the base is

30. Pressure is introduced in fluid mechanics as

31. Water drops placed on a waxy surface often form rounded beads. This observation is mainly connected with

32. A liquid drop and a soap bubble have the same radius and the same surface tension . The ratio of excess pressure in the liquid drop to that in the soap bubble is

33. A soap solution forms bubbles more easily than pure water because the soap solution has

34. A curved ball in air can experience a sideways force when spinning. At a basic-level explanation, this is because spin can make air speed different on opposite sides, producing

35. Water flows steadily from a lower section P to a higher section Q of a pipe. At P, , , and . At Q, , and . Taking and , the pressure is

36. A horizontal pipe has a wide section and a narrow section. A manometer shows that . If water of density flows ideally and the speed in the wide section is , the speed in the narrow section is

37. A student argues that faster fluid must always have higher pressure because it has more kinetic energy. The correct Bernoulli-based response for horizontal ideal flow is that

38. The buoyant force on a body fully immersed in a liquid is increased when

39. A graph is plotted between and depth for liquid emerging from small holes in a large tank. According to Torricelli’s theorem, the slope of the graph is

40. Study the table and identify the row that gives the most suitable explanation.

41. A cube floats in water with of its volume submerged. The same cube is then placed in a liquid of density . If the cube floats again, the fraction of its volume submerged in the new liquid is

42. A student says, “A fluid with larger density must always have larger viscosity.” The best correction is that

43. Density of a fluid sample is best described by

44. A force diagram for a stone suspended by a string while fully immersed in water should include

45. For a spherical liquid drop of radius and surface tension , the excess pressure inside the drop is

46. A solid object floats in a liquid when its average density is

47. For flow through a pipe, Reynolds number is commonly written as

48. A pressure difference of drives laminar flow through a tube. When the pressure difference is increased to without changing , , or , the new flow rate is

49. The dimensional formula of coefficient of viscosity is

50. 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