Mechanical Properties of Fluids Mock Test – Class 11 Physics

1. A block is suspended from a string and fully immersed in a liquid. If the block is at rest, the tension in the string is

2. Study the table and identify the correct graph interpretation.

3. A student uses for a water droplet in air. The main error is that this formula is for

4. A liquid is at rest in a container. Point P is below the free surface, while point Q is below the free surface. The pressure difference is

5. A glass capillary is dipped in mercury. The meniscus is expected to be

6. A capillary-rise graph of against is drawn for the same liquid and same tube material. If detergent is added and the graph is redrawn under nearly the same conditions, the slope is expected to

7. In a hydraulic lift, a pressure of acts on a large piston of area . The load supported by this piston is

8. A body is fully immersed in a liquid and neither rises nor sinks. This condition is called neutral equilibrium, and it occurs when

9. 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.

10. Assertion: Surface tension has the same dimensional formula as surface energy per unit area.
Reason: Surface tension can also be interpreted as work required to increase unit surface area.

11. A claim says, “A sinking object has no buoyant force acting on it.” The best correction is that a sinking object

12. A graph is plotted with buoyant force on the vertical axis and displaced volume on the horizontal axis for a fixed liquid. The graph is a straight line through the origin. Its slope is

13. 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

14. Adding detergent to water used in a capillary tube usually lowers the capillary rise because detergent

15. 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

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

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

18. A pressure gauge reads zero when exposed to open air. This happens because the gauge

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

20. 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

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

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

23. A floating object has of its volume submerged in a liquid. If the liquid density is , the average density of the object is

24. A rectangular block of height and horizontal area is fully immersed in water. The top face is at depth . Take and . The net upward force due to pressure on the top and bottom faces is

25. For Bernoulli’s equation to be applied in its usual form along a streamline, the flow should be

26. A rectangular vertical gate is wide and holds water to a depth of . Take and . The force on the gate due to gauge pressure is

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

28. 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.

29. In the capillary-rise formula , the contact angle is used in radians for calculation. Which statement gives the correct dimensional interpretation?

30. A small insect can stand on the surface of clean water mainly because the water surface

31. A student compares four formula uses in mechanical properties of fluids.

Which row contains the unsuitable formula use?

32. A small liquid drop has greater excess pressure than a large drop of the same liquid because the smaller drop has

33. A liquid and a gas are compared in ordinary conditions. The better comparison is that

34. Assertion: In an ideal hydraulic press, the pressure at the small piston and the large piston can be the same.
Reason: Pressure applied to an enclosed incompressible fluid is transmitted undiminished in all directions.

35. A Venturi tube has a wide section and a narrow throat. In steady incompressible ideal flow through it, the pressure at the throat is lower mainly because

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

37. For many gases, increasing temperature generally makes viscosity

38. Use the arrangement described below.

Which pressure-force comparison gives the origin of the net buoyant force?

39. Capillary action occurs when a liquid rises or falls in a narrow tube due to the combined effect of

40. A formula-selection table is prepared for common fluid-mechanics situations.

Which row is incorrectly matched?

41. A Pitot tube is used to estimate the speed of a liquid. If the pressure difference between stagnation point and free stream is , the speed of an ideal incompressible liquid of density is

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. A dam wall is made thicker near its base mainly because

44. Study the table and identify the row that is correctly matched.

45. A solid weighs in air and when fully immersed in water. If the density of water is and , the volume of the solid is

46. 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.

47. An open tank contains oil of density to a depth of . If and atmospheric pressure is , the absolute pressure at the bottom is

48. Study the table and identify the row that gives the best surface-tension explanation.

49. Use the graph description below.

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

50. A small sphere falls through a viscous liquid. At a certain instant before terminal velocity, its speed is increasing. Which force comparison is correct?