Mechanical Properties of Fluids Mock Test – Class 11 Physics

1. A rectangular block floats in liquid P with of its volume submerged and in liquid Q with of its volume submerged. The density comparison of the liquids is

2. In pipe flow, increasing the pipe diameter while keeping , , and unchanged makes Reynolds number

3. In a steady incompressible flow, a pipe divides into two identical branches. The main pipe has area and speed . Each branch has area . If the flow divides equally, the speed in each branch is

4. A graph is plotted between shear stress and velocity gradient for a Newtonian fluid. The graph is a straight line through the origin. The slope represents

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

6. A horizontal water pipe gradually narrows from diameter to diameter . If the speed in the wider part is , the speed in the narrower part is

7. A manometer gives the same height difference first with water and then with mercury. For the same , the pressure difference indicated by mercury is larger because mercury has

8. The capillary rise or depression in a tube of radius is given by

9. Read the situation and answer the question.

In this situation, the upward push of water is called

10. In a hydraulic system, the small piston is pressed down slowly. The large piston lifts a heavy object. The reason a small input force can lift a heavy load is best described as

11. 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

12. Consider the following statements about angle of contact and meniscus.
Statement I: A wetting liquid generally has an acute angle of contact.
Statement II: A non-wetting liquid generally has an obtuse angle of contact.
Statement III: A convex meniscus is typical for mercury in clean glass.

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

14. A table gives four descriptions of pressure in a fluid at rest.

Which row is unsuitable for a fluid at rest?

15. Surface tension is defined as force per unit length. Its relation is

16. A mercury barometer shows a height of at standard atmospheric pressure. This height means the atmosphere can support

17. A graph of surface tension against temperature for a typical liquid is expected to show

18. A clean steel needle may float on water if placed carefully, although steel is denser than water. The best explanation is that

19. Poiseuille’s law for steady laminar flow through a capillary tube shows that volume flow rate is extremely sensitive to the tube radius because

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

21. A tank of total water height has a small hole at depth below the free surface. The hole is therefore at height above the ground. Under ideal conditions, the horizontal range of the jet is maximum when

22. 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

23. A pressure of acts uniformly on an area of . What normal force is acting on the area?

24. A liquid of mass has density . Its volume is

25. Water in a clean glass capillary forms a concave meniscus because

26. The derivation of capillary rise equates the upward surface-tension force around the rim to the

27. Study the table and identify the correct row.

28. A hydraulic lift raises a car of weight using a large piston of area . The small piston has area . Ignoring losses, the minimum force on the small piston is

29. Bernoulli’s equation should not be used directly for a fluid at rest to replace the hydrostatic relation unless the velocity terms are treated correctly because

30. Use the arrangement described below.

If the containers are at rest and is the same, the gauge pressures at P, Q, and R are

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

32. A liquid surface in a vessel at rest is normally horizontal because otherwise

33. The volume flow rate through a pipe is the volume of fluid crossing a section per unit time. If the section area is and average speed is , then

34. Consider the following statements about floating bodies.
Statement I: A floating body displaces fluid whose weight equals the weight of the body.
Statement II: A floating body must always be completely submerged.
Statement III: The fraction submerged depends on the ratio .

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

36. A capillary tube is dipped in a wetting liquid. The liquid rises to height . If the same experiment is repeated with a liquid of the same surface tension and contact angle but twice the density, the capillary rise becomes

37. A soap bubble is formed from a liquid of surface tension . If its radius is , the work needed to form the bubble from an initially negligible film area is

38. Use the graph description below.

The area under this -versus- graph from to , multiplied by the wall width, represents

39. In deriving , a liquid column of height is considered in equilibrium. The force balance works because the pressure force at the lower face must balance

40. Consider the following statements about Bernoulli’s principle.
Statement I: In horizontal ideal flow, higher speed is associated with lower pressure.
Statement II: Bernoulli’s equation is applied along a streamline under ideal-flow conditions.
Statement III: The term has the same unit as pressure.

41. For a body displacing volume of a fluid of density , the buoyant force is

42. For a vertical rectangular wall in contact with water from the free surface down to depth , the pressure distribution is best described as

43. The line of action of the buoyant force on a completely immersed body passes through the

44. A graph is plotted between excess pressure and for liquid drops of the same liquid. The slope represents

45. Study the table and identify the row that gives the best conclusion.

46. Which pair is correctly matched?

47. Use the arrangement described below.

Which pair should be classified as fluids?

48. A teacher asks why a static fluid pushes normally on the wall of its container rather than exerting a steady sideways rubbing force along the wall. The best explanation is that a fluid at rest

49. For a soap bubble of radius , the excess pressure inside it is because a soap bubble has

50. Consider the following statements about a horizontal Venturi tube.
Statement I: The throat has smaller area than the wide section.
Statement II: The speed at the throat is greater for steady incompressible flow.
Statement III: The static pressure at the throat is greater because the fluid is squeezed.