# Mechanical Properties of Fluids Class 12 MCQ

Mechanical Properties of Fluids Class 12 MCQ: Class 12 Physics MCQ Questions and Answer. Students get here all Important MCQ on Mechanical Properties of Fluids Class 12.

## Mechanical Properties of Fluids Class 12 MCQ with Answers:

1) Any substance that can flow is …………

a) fluids

b) Solid

c) Crystalline solid

d) Supercooled liquids

Ans- a) fluids

2) A ………… means a substance that can flow.

a) Solid

b) Semisolid

c) Material

d) None of the above

Ans-None of the above

3) Ideal fluid has

a) Rotational flow

b) Viscosity

c) Constant density

Ans – c) constant density

4) Ideal fluid has

e) Different density

f) No Viscosity

g) Rotational flow

Ans – f) no viscosity

5) Ideal fluid has

i) Different density

j) Viscosity

k) Irrotational flow

Ans – j) Irrotational flow

6) Ideal fluid has

m) Different density

n) Viscosity

o) Rotational flow

7) most fluids show

a) weak resistance to deformation

b) no resistance to deformation

c) high resistance to deformation

d) none of the above.

Ans – a) weak resistance to deformation

8) due to surface tension water droplets are

a) irregular in shape

b) square in shape

c) rectangle in shape

d) spherical in shape

ans- d) spherical in shape

9) : A swimmer is swimming in a swimming pool at 10 m below the surface of the water. Calculate the pressure on the swimmer due to water above. (Density of water = 1000 kg/m3 , g = 9.8 m/s2 )

a) 98000 p

b) 9800 p

c) 10 p

d) 9.8 p

Ans- a) 98000p

10) Instrument used for measurement of measurement of atmospheric pressure.

a) Galvanometer

b) Barometer

c) Sphygmomanometer

d) Thermometer

Ans – b) barometer

11) A spider can walk on the surface of water due to

a) Viscosity

b) Elasticity

c) Pressure

d) Surface tension

Ans- d) surface tension

12) Net cohesive force acting on the molecule is zero when

a) Molecule is deep inside the liquid

b) Molecule is on the surface of the liquid

c) Molecule is on the free surface of the liquid

d) None of the above

Ans – a) molecule is deep inside the liquid

13) The force of attraction between molecules of the same substance

b) Cohesive force

c) Ionic forces

d) None of the above

Ans- b) cohesive force

14) The force of attraction between molecules of the same substance

f) Cohesive force

g) All of the above

h) None of the above

15) Intermolecular forces is effective only within

a) Outside the sphere of influence

b) Outside the molecular range

c) Just outside the sphere of influence

d) Inside the sphere of influence.

Ans- d) inside the sphere of influence.

16) The force due to surface tension acts ______ to the surface of a liquid.

a) Perpendicular

b) Parallel

c) Tangential

d) Towards the centre.

Ans- c) tangential

17) S.I. unit of surface tension is

a) N/m

b) Nm

c) N/m2

d) N/m3

Ans – a) N/m

18) A beaker of radius 20 cm is filled with water. Calculate the force of surface tension on any diametrical line on its surface. Surface tension of water is 0.075 N/m.

a) 0.003

b) 0.3

c) 3

d) 0.03

Ans – d) 0.03

19) When common salt is added to water, surface tension

a) Decreases

b) Does not change

c) Increases

d) Can’t predict

Ans – c) increases

20) When detergent is added to water, surface tension

a) Decreases

b) Does not change

c) Increases

d) Can’t predict

Ans – a) decreases

21) When detergent is added to water, surface tension

e) Decreases

f) Does not change

g) Increases

h) Can’t predict

Ans – e) decreases

22) In most liquid, surface tension decreases when temperature

a) Increases

b) Does not change

c) Decreases

d) Can’t predict

Ans- decreases

23) Surface tension of a liquid become ____ at critical temperature

a) Increases

b) Decreases

c) Maximum

d) Zero

Ans – d) zero

24) What is the excess pressure inside the bubble when diameter of the water molecule is 14.54 mm. (surface tension of water = 7.27 x 10-2 N/m).

a) 2 N/m2

b) 20 N/m2

c) 200 N/m2

d) 0.2 N/m2

Ans- c) 200 N/m2

25) What is the excess pressure inside the bubble when radius of the water molecule is 7.27 mm. (surface tension of water = 7.27 x 10-2 N/m).

e) 2 N/m2

f) 20 N/m2

g) 200 N/m2

h) 0.2 N/m2

Ans- c) 200 N/m2

26) What is the excess pressure inside the bubble when diameter of the water molecule is 14.54 cm. (surface tension of water = 7.27 x 10-2 N/m).

i) 2 N/m2

j) 20 N/m2

k) 200 N/m2

l) 0.2 N/m2

Ans- b) 20 N/m2

27) What is the excess pressure inside the bubble when radius of the water molecule is 7.27 cm. (surface tension of water = 7.27 x 10-2 N/m).

m) 2 N/m2

n) 20 N/m2

o) 200 N/m2

p) 0.2 N/m2

Ans- c) 200 N/m2

28) The friction between the two layers is called as

a) Viscosity

b) Critical velocity

c) Streamline flow

d) None of the above

Ans- a) viscosity

29) S.I. unit of viscosity is

a) Ns x m2

b) N / sm2

c) N/ sm3

d) Ns/m2

Ans- d) Ns/m2

30) Spherical object falling through a viscous fluid the viscous force experienced by the body is directed in

a) Upward direction

b) Downward direction

c) Tangential

d) Has no direction.

Ans – a) upward direction.

31) Spherical object falling through a viscous fluid the gravitational force experienced by the body is directed in

e) Upward direction

f) Downward direction

g) Tangential

h) Has no direction.

Ans – b) downward direction.

32) Spherical object falling through a viscous fluid the buoyant force experienced by the body is directed in

i) Upward direction

j) Downward direction

k) Tangential

l) Has no direction.

Ans – a) upward direction.

Updated: August 11, 2023 — 8:51 pm