# MCQ Questions for Class 11 Physics Chapter 10 : Mechanical Properties of Fluids with Answers

Here we prepared a comprehensive Fluids mechanics MCQ for NEET Pdf form. These MCQ on mechanical properties of fluids for NEET are based on questions asked in different medical entrance exam like AIIMS, JIPMER, and NEET and other state level medical entrance exam. All Fluid mechanics NEET Questions and Answers in the given below are prepared from previous year papers of all most all entrance exam. We have prepared Fluid s mechanics NEET previous year Questions separately. Take a Look Below:

## Fluids mechanics MCQs For NEET

1.If the density of the material increase, the value of Young’s modulus_____________

(a) increases

(b) decreases

(c) first increases, then decreases

(d) first decreases, then increases

2. Two wires of the same material and length but diameters in the ratio 1 : 2 are stretched by the same force. The potential energy per unit volume for the two wires when stretched will be in the ratio.

(a) 16 : 1

(b) 4 : 1

(c) 2 : 1

(d) 1 : 1

3. A weight is suspended from a long metal wire. If the wire suddenly breaks, its temperature________________

(a) rises

(b) falls

(c) remains unchanged

(d) attains a value 0 K

4. By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg(density = 13·6 gm/cm3). Using the straw, he can drink water from a glass upto a maximum depth of___________

(a) 10 cm

(b) 75 cm

(c) 13·6 cm

(d) 1·36 cm

5.The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied ?

(a) length = 300cm, diameter = 3mm

(b) length = 50 cm, diameter = 0.5 mm

(c) length = 100 cm, diameter = 1mm

(d) length = 200 cm, diameter = 2mm

6. The wettability of a surface by a liquid depends primarily on______________

(a) angle of contact between the surface and the liquid

(b) viscosity

(c) surface tension

(d) density

7. A small sphere of radius ‘r’ falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to_______________

(a) r³

(b) r²

(c) r⁵

(d) r⁴

8. Two wires are made of the same material and have the same volume. The first wire has cross-sectional area A and the second wire has cross-sectional area 3A. If the length of the first wire is increased by ∆/ on applying a force F, how much force is needed to stretch the second wire by the same amount ?

(a) 9F

(b) 6F

(c) 4F

(d) F

9. A ball rises to surface at a constant velocity in liquid whose density is 4 times than that of the material of the ball. The ratio of the force of friction acting on the rising ball and its weight is____________

(a) 3 : 1

(b) 4 : 1

(c) 1 : 3

(d) 1 : 4

10. If more air is pushed in a soap bubble, the pressure in it_______________

(a) decreases

(b) increase

(c) remains same

(d) becomes zero

11. When a large bubble rises from the bottom of a lake to the surface, its radius doubles. If atmospheric pressure is equal to that of column of water height H, then the depth of lake is_________________

(a) H

(b) 2H

(c) 7H

(d) 8H

12. Which one of the following will make its way most easily through the tiny space between the fiber of the clothing___________

(a) Glycerene at 20°C

(b) Water at 20°C

(c) Soap water at 20°C

(d) Water at 100°C

13. A wooden cube just floats inside water when a 200 g mass is placed on it. When the mass is removed the cube is 2 cm above water level. The side of cube is____________

(a) 5 cm

(b) 10 cm

(c) 15 cm

(d) 20 cm

14. Water emerges out as a fountain from a vertical tube at the rate of 3000 ltr/min upto height 10m.What is the area of cross section of the tube ?

(a) 35 cm²

(b) 40 cm²

(c) 80 cm²

(d) 17 cm²

15. Water rises to height ‘h’ in capillary tube. If the length of capillary tube above the surface of water is made less than ‘h’, then_____________

(a) water does not rise at all.

(b) water rises upto the tip of capillary tube and then starts overflowing like a fountain.

(c) water rises upto the top of capillary tube and stays there without overflowing.

(d) water rises upto a point a little below the top and stays there.

16. Water is flowing with velocity 4m/sec in a cylinder of diameter 8cm, it is connected to a pipe with its end tip of diameter 2cm, calculate the velocity of water at this free end____________

(a) 4 m/s

(b) 8 m/s

(c) 32 m/s

(d) 64 m/s

17. The excess pressure inside a soap bubble A is twice that in another soap bubble B. The ratio of volumes of A and B is_______________

(a) 1 : 2

(b) 1 : 4

(c) 1 : 8

(d) 1 : 16

18. In a capillary tube experiment, a vertical 30 cm long capillary tube is dipped in water. The water rises up to a height of 10 cm due to capillary action.If this experiment is conducted in a freely falling elevator, the length of the water column becomes__________________

(1) 10 cm

(2) 20 cm

(3) 30 cm

(4) Zero

19. A soap bubble in vacuum has a radius of 3 cm and another soap bubble in vacuum has a radius of 4cm. If the two bubbles coalesce under isothermal condition, then the radius of the new bubble is____________

(a) 2.3 cm

(b) 4.5 cm

(c) 5 cm

(d) 7 cm

20. The spherical shape of rain-drop is due to__________________

(a) Density of the liquid

(b) Surface tension

(c) Atmospheric pressure

(d) Gravity

21. In a capillary tube, water rises by 1.2 mm. The height of water that will rise in another capillary tube having half the radius of the first, is _________________

(a) 1.2 mm

(b) 2.4 mm

(c) 0.6 mm

(d) 0.4 mm

22. A water drop is divided into 8 equal droplets. The pressure difference between inner and outer sides of the big drop

(a) will be the same as for smaller droplet

(b) will be half of that for smaller droplet

(c) will be one-forth of that for smaller droplet

(d) will be twice of that for smaller droplet.

23. A false statement is_______________

(1) Angle of contact q < 90°, if cohesive force < adhesive force × √2

(2) Angle of contact q > 90°, if cohesive force > adhesive force × √2

(3) Angle of contact q = 90°, if cohesive force = adhesive force × √2

(4) If the radius of capillary is reduced to half, the rise of liquid column becomes four times

24. Bernoulli’s equation for steady, non-viscous, in compressible flow expresses the_________

(a) Conservation of angular momentum

(b) Conservation of density

(c) Conservation of momentum

(d) Conservation of mechanical energy.

25. Application of Bernoulli’s theorem can be seen in___________

(a) Dynamic lift to aeroplane

(b) Hydraulic press

(c) Speed Boat

(d) None of these

26. Work done in forming a soap bubble of radius R is W. Then workdone is forming a soap bubble of radius ‘2R’ will be_________

(a) 2W

(b) 4W

(c) W/2

(d) W/4

27. At which angle liquid will not wet solid.

(a) Zero

(b) acute

(c) 45°

(d) obtuse

28. Scent sprayer is based on________

(a) Charle’s law

(b) Archimede’s principle

(c) Boyle’s law

(d) Bernoulli’s theorem

29. Spiders and insects move and run about on the surface of water without sinking because_____________

(a) Elastic membrane is formed on water due to property of surface tension

(b) Spiders and insects are lighter

(c) Spiders and insects swim on water

(d) Spiders and insects experience up-thrust

30. A sphere is floating in water its 1/3rd part is outside the water and when sphere is floating in unknown liquid, its ¾th part is outside the liquid then density of liquid is________________

(a) 4/9 gm/c.c.

(b) 9/4 gm/c.c.

(c) 8/3 gm/c.c.

(d) 3/8 gm/c.c.

31. Which of the following works on Pascal’s law ?

(a) Sprayer

(b) Venturimeter

(c) Hydraulic lift

(d) Aneroid barometer

32. A small drop of water falls from rest through a large height h in air. The final velocity is_______________

(a) almost independent of h

(b) proportional to h

(c) proportional to h

(d) inversely proportional to h

33. Poisson’s ratio can not have the value ______________

(a) 0.1

(b) 0.7

(c) 0.2

(d) 0.5

34. A sample of metal weights 210 gram in air, 180 gram in water and 120 gram in an unknown liquid. Then____________

(a) the density of metal is 3 g/cm³

(b) the density of metal is 7 g/cm³

(c) density of metal is 4 times the density of the unknown liquid

(d) the metal will float in water