## Class 11 Physics Objective Chapter – 10 Mechanical Properties of Fluids

Here we are providing NCERT Class 11 Physics Objective Chapter – 10 Mechanical Properties of Fluids  Chapter Wise MCQs for board exam is very important for board exam preparation. This book explains all the concepts and topics in very simple language that the students can easily understand the complex subjects also. This NCERT Class 11 Physics MCQs Chapter – 10 Mechanical Properties of Fluids  Chapter consist all important topic regarding NCERT Class 11 Physics Objective Chapter – 10 Mechanical Properties of Fluids . This book basically covers all the major and minor elements that together form a democratic government. Topics like power-sharing, federalism, democracy and diversity, political parties, consequences of democracy, challenges to democracy etc. have been discussed in the NCERT Class 11 Physics Objective Chapter –10 Mechanical Properties of Fluids . The question papers in CBSE board exams are generally based on the latest NCERT books. Hence, students must follow the NCERT book to prepare effectively for their Class 11 Physics exam. If you want color notes then click here

Class 11 Physics Objective Chapter – 10 Mechanical Properties of Fluids

1. A number of small drops of mercury coalesce adiabatically to form a single drop. The temperature of drop

( a )  Increases

( b )  Is infinite

( c )  Remains unchanged

( d )  May decrease or increase depending upon size

Ans:- ( d )

2. An ice cube contains a large air bubble. The cube is floating on the surface of water contained in a trough. What will happen to the water level, when the cube melts?

( a )  It will rise.

( b )  It will fall.

( c )  First it will fall then rise

( d )  It will remain unchanged

Ans:- ( d )

3. If two pieces of metal when immersed in a liquid have equal upthrust on them, then both pieces have equal

( a ) mass

( b ) density

( c ) volume

( d ) weight

Ans:- ( c )

4. Surface tension of a soap solution is 1.9 × 10-2N/m. work done in blowing a bubble of 2.0 cm diameter will be

( a )  7.6 × 10-6 p J

( b )  15.2 × 10-6 p J

( c )  1.9 × 10-6 p J

( d )  1 × 10-4 p J

Ans:- ( b )

5. Plants get water through the roots because of

( a )  Capillarity

( b )  Viscosity

( c )  Gravity

( d )  Elasticity

Ans:- ( a )

6. A liquid is allowed to flow into a tube of truncated cone shape. Identify the correct statement from the following

( a )  The speed is high at the wider end and high at the narrow end.

( b )  The speed is low at the wider end and high at the narrow end.

( c )  The speed is same at both ends in a stream line flow.

( d )  The liquid flows with uniform velocity in the tube.

Ans:- ( b )

7. The unit of pressure is _____.

(a) N / m2

(b) Dyn / cm2

(c) pascal

(d) all of the above

Ans:- ( d )

8. Choose the wrong statement from the following.

( a )  Small droplets of a liquid are spherical due to surface tension

( b )  Oil rises through the wick due to capillarity

( c )  In drinking the cold drinks through a straw, we use the phenomenon of capillarity

( d )  Gum is used to stick two surfaces. In this process we use the property of Adhesion

Ans:- ( c )

9. Water rises up to a height h1 in a capillary tube of radius r. the mass of the water lifted in the capillary tube is M. if the radius of the capillary tube is doubled, the mass of water that will rise in the capillary tube will be

( a )  M

( b )  2M

( c )  M/2

( d )  4M

Ans:- ( b )

10. The height of a liquid in a fine capillary tube

( a )  Increases with an increase in the density of a liquid

( b )  Decreases with a decrease in the diameter of the tube

( c )  Decreases with an increase in the surface tension

( d )  Increases as the effective value of acceleration due to gravity is decreased

Ans:- ( d )

11. A person is carrying a bucket in one hand and a fish in the other. If he puts fish in the bucket, how will the load carried by the person change?

( a )  It will be less.

( b )  It will be more.

( c )  No change.

( d )  It will depend on the mass of the fish.

Ans:- ( c )

12. For tap water and clean glass, the angle of contact is

( a ) 0°

( b ) 90°

( c ) 140°

( d ) 8°

Ans:- ( d )

13. At critical temperature, the surface tension of a liquid

( a )  Is zero

( b )  Is infinity

( c )  Is the same as that at any other temperature

( d )  Can not be determined

Ans:- ( a )

14. A capillary tube when immersed vertically in a liquid records a rise of 3 cm. if the tube is immersed in the liquid at an angle of 60° with the vertical, then length of the liquid column along the tube will be

( a )  2 cm

( b )  3 cm

( c )  6 cm

( d )  9 cm

Ans:- ( c )

15.The rain drops falling from the sky neither injure us nor make holes on the ground because they move with

( a )  constant acceleration

( b )  variable acceleration

( c )  variable speed

( d )  constant terminal velocity

Ans:- ( b )

16. According to archimedes’ principle, loss of weight of a body immersed in a liquid is equal to

( a ) weight of the liquid displaced

( b ) weight of the total liquid

( c ) weight of the body

( d ) none of these

Ans:- ( a )

17. When the angle of contact between a solid and a liquid is 90°, then

( a )  Cohesive force > Adhesive force

( b )  Cohesive force < Adhesive force

( c )  Cohesive force = Adhesive force

( d )  Cohesive force >> Adhesive force

Ans:- ( c )

18.When a soap bubble is charged

( a )  It contracts

( b )  It expands

( c )  It does not undergo any change in siz

( d )  None of these

Ans:- ( b )

19.Water rises up to a height of 5 cm in a capillary tube of radius 2 mm. what is the radius of the radius of the capillary tube if the water rises up to a height of 10 cm in another capillary?

( a )  4 mm

( b )  1 mm

( c )  3 mm

( d )  1 cm

Ans:- ( b )

20.For a floating body to be in stable equilibrium, where should its centre of buoyancy be located?

( a )  At the centre of gravity.

( b )  Above the centre of gravity.

( c )  Below the centre of gravity.

( d )  It may be anywhere.

Ans:- ( b )

21. If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of container is

( a )  Acute angle

( b )  Obtuse angle

( c )  90°

( d )  0°

Ans:- ( d )

22. Two soap bubbles have radii in the ratio of 4 : 3. What is the ratio of work done to below these bubbles?

( a )  4 : 3

( b )  16 : 9

( c )  09 : 16

( d )  3 : 4

Ans:- ( b )

23. Liquid pressure depends upon

( a )  height of the liquid column

( b )  directions

( c )  shape of the liquid surface

( d )  area of the liquid surface

Ans:- ( a )

24. An ice-berg floating partly immersed in sea water of density 1.03 g/cm3. The density of ice is 0.92 g/cm3. The fraction of the total volume of the iceberg above the level of sea water is

( a )  8.1%

( b )  11%

( c )  34%

( d )  0.8%

Ans:- ( b )

25.What is the correct relation among force ( F ) , pressure ( P )  and area ( A ) ?

( a ) F = P / A

( b ) F = A / P

( c ) A = F x P

( d ) P = F / A

Ans:- ( d )

26. Hydraulic lifts and hydraulic brakes are based on

( a )  Pascal’s law

( b )  Bernoulli’s principle

( c )  Archimedes’ principle

( d )  Stoke’s law

Ans:- ( a )

27. A liquid is kept in a glass vessel. If the liquid solid adhesive force between the liquid and the vessel is very weak as compared to the cohesive force in the liquid, then the shape of the liquid surface near the solid should be

( a )  Concave

( b )  Convex

( c )  Horizontal

( d )  Almost vertical

Ans:- ( b )

28. Water rises up to a height of 4 cm, in a capillary tube immersed vertically in water. What will be the length of water column in the capillary tube, if the tube is immersed in water, at an angle of 60° with the vertical?

( a )  4 cm

( b )  6 cm

( c )  8 cm

( d )  2 cm

Ans:- ( c )

29.Why the aeroplanes are made to run on the runway before take off?

( а )  It decreases the friction.

( b )  It decreases atmospheric pressure.

( c )  It decreases viscous drag of the air.

( d )  It provides required lift to the aeroplane.

Ans:- ( d )

30.Sudden fall in the atmospheric pressure by a large amount shows

( a )  rain

( b )  fair weather

( c )  cloud wave

( d )  storm

Ans:- ( d )

31. Pressure inside two soap bubbles is 1.01 and 1.02 atmospheres. ratio between their volume is

( a )  102 : 101

( b )  ( 102 ) 3 : ( 101 ) 3

( c )  8 : 1

( d )  2 : 1

Ans:- ( c )

32. ——and——-play the same role in case of fluids as force and mass play in case of solids

( a )  Pressure and density

( b )  Thrust and volume

( c )  Thrust and density

( d )  Pressure and thrust

Ans:- ( a )

33. A boat having a length of 3 metres and breadth 2 metres is floating on a lake. The boat sinks by one cm when a man gets on it. The mass of the man is

( a )  60 kg

( b )  62 kg

( c )  72 kg

( d )  128 kg

Ans:- ( a )

34.Sleepers of wooden or concrete are kept below the railway track for

( a )  decreasing pressure

( b )  decreasing area

( c )  decreasing force

( d )  none of these

Ans:- ( a )

35. Pressure applied to enclosed fluid is

( a )  transmitted unchanged to every portion of the fluid and wall of containing vessel.

( b )  increased in proportion to the mass of the fluid and then transmitted

( c )  diminished and transmitted to wall of container

( d )  increased and applied to every part of the fluid

Ans:- ( a )

36. A capillary tube is placed vertically in a liquid. If the cohesive force is less than the adhesive force, then

( a )  The meniscus will be convex upwards

( b )  The liquid will wet the solid

( c )  The angle of contact will be obtuse

( d )  The liquid will drip in the capillary tube

Ans:- ( b )

37. The surface of water in contact with glass wall is

( a )  Plane

( b )  concave

( c )  convex

( d )  Both b and c

Ans:- ( b )

38.When the temperature of a liquid increases, its surface tension

( a )  increases.

( b )  decreases.

( c )  remains unchanged.

( d )  none of the above.

Ans:- ( b )

39.Pressure inside two soap bubbles is 1.01 and 1.02 atmospheres. ratio between their volume is

( a )  102 : 101

( b )  ( 102 ) 3 : ( 101 ) 3

( c )  8 : 1

( d )  2 : 1

Ans:- ( c )

40. One end of a towel dips into a bucket full of water and other end hangs over the bucket. It is found that after some time the towel becomes fully wet. It happens

( a )  Because viscosity of eater is high

( b )  Because of the capillary action of cotton threads

( c )  Because of gravitational force

( d )  Because of evaporation of water

Ans:- ( c )

41. Pressure applied to enclosed fluid

( a )  transmitted unchanged to every portion of the fluid and wall of containing vessel.

( b )  increased in proportion to the mass of the fluid and then transmitted

( c )  diminished and transmitted to wall of container

( d )  increased and applied to every part of the fluid

Ans:- ( a )

42. The excess of pressure inside a soap bubble is twice the excess pressure inside a second soap bubble. The volume of the first bubble is n times the volume of the second where n is

( a )  0.125

( b )  0.250

( c )  1

( d )  2

Ans:- ( a )

43. The unit of surface tension is

( a ) N / m2

( b ) N / m

( c ) N-m

( d ) N-m2

Ans:- ( b )

44. The pressure at the bottom of a tank containing a liquid does not depend on

( a )  area of the bottom surface

( b )  nature of the liquid

( c )  height of the liquid column

( d )  acceleration due to gravity

Ans:- ( a )

45. When there are no external forces, the shape of a liquid drop is determined by

( a )  Surface tension of the liquid

( b )  Density of liquid

( c )  Viscosity of liquid

( d )  Temperature of air only

Ans:- ( a )

46. One end of a towel dips into a bucket full of water and other end hangs over the bucket. It is found that after some time the towel becomes fully wet. It happens

( a )  Because viscosity of eater is high

( b )  Because of the capillary action of cotton threads

( c )  Because of gravitational force

( d )  Because of evaporation of water.

Ans:- ( b )

47. Insects are able to run on the surface of water because

( a )  surface tension makes its surface to behave as an elastic membrane.

( b )  insects swim on water.

( c )  insects have less weight.

( d )  of Archimede’s upthrust

Ans:- ( a )

48.The surface of water in contact with glass wall is

( a )  Plane

( b )  concave

( c )  convex

( d )  Both b and c

Ans:- ( b )

49. If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of container is

( a )  Acute angle

( b )  Obtuse angle

( c )  90°

( d )  0°

Ans:- ( d )

50. The pressure at the bottom of a tank containing a liquid does not depend on

( a )  area of the bottom surface

( b )  nature of the liquid

( c )  height of the liquid column

( d )  acceleration due to gravity

Ans:- ( a )

51.The level of water in a tank is 5m high. A hole of area 1 cm2 is made in the bottom of the tank. The rate of leakage of water from the hole ( g = 10 m/s2 )  is

( a )  10–2 m3/s

( b )  10–3 m3/s

( c )  10–4 m3/s

( d )  103 m3/s

Ans:- ( b )

52. A person swimming in a fresh water pool swims, obeying

( a )  Newton’s first law

( b )  Newton’s second law

( c )  Newton’s third law

( d )  gravitational law

Ans:- ( c )