# [MCQ] Mechanical Properties of Fluids MCQ | Mechanical Properties of Fluids

### [MCQ] Mechanical Properties of Fluids MCQ | mechanical properties of fluids mcq questions

Question 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
Solutions : (d) May decrease or increase depending upon size

Question 2. 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
Solutions : (b) 15.2 × 10-6 p J

Question 3. Plants get water through the roots because of
(a) Capillarity
(b) Viscosity
(c) Gravity
(d) Elasticity
Solutions : (a) Capillarity

Question 4. 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
Solutions : (c) In drinking the cold drinks through a straw, we use the phenomenon of capillarity

Question 5. 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
Solutions : (d) Increases as the effective value of acceleration due to gravity is decreased

Question 6. 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
Solutions : (a) Is zero

Question 7. 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
Solutions : (c) 6 cm

Question 8. 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
Solutions : (c) Cohesive force = Adhesive force

Question 9. 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
Solutions : (b) 1 mm

Question 10. 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°
Solutions : (d) 0°

Question 11. 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
Solutions : (b) 16 : 9

Question 12. The height of water in a capillary tube of radius 2 cm is 4 cm. what should be the radius of capillary, if the water rises to 8 cm in tube?
(a) 1 cm
(b) 0.1 cm
(c) 2 cm
(d) 4 cm
Solutions : (a) 1 cm

Question 13. 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
Solutions : (c) 8 cm

Question 14. The surface of water in contact with glass wall is
(a) Plane
(b) concave
(c) convex
(d) Both b and c
Solutions : (b) concave

Question 15. 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
Solutions : (c) 8 : 1

Question 16. 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.
Solutions : (b) Because of the capillary action of cotton threads

Question 17. 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°
Solutions : (d) 0°

Question 18. Water rises up to a height h, 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
Solutions : (b) 2M

Question 19. 5 g of water rises in the bore of capillary tube when it is dipped in water. If the radius of bore capillary tube is doubled, the mass of water that rises in the capillary tube above the outside water level is
(a) 1.5 g
(b) 10 g
(c) 5 g
(d) 15 g
Solutions : (b) 10 g

Question 20. 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
Solutions : (d) Increases as the effective value of acceleration due to gravity is decreased

### Mechanical Properties of Fluids | [MCQ] Mechanical Properties of Fluids MCQ

Question 1. 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.
Solutions : (d) It will remain unchanged.

Question 2. 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.
Solutions : (c) No change.

Question 3. 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.
Solutions : (b) Above the centre of gravity.

Question 4. 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.
Solutions : (d) It provides required lift to the aeroplane.

Question 5. When the temperature of a liquid increases, its surface tension
(a) increases.
(b) decreases.
(c) remains unchanged.
(d) none of the above.
Solutions : (b) decreases.

Question 6. 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.
Solutions : (a) surface tension makes its surface to behave as an elastic membrane.

Question 7. A drop of water is broken into two drops. The sum of which property of the two drops is equal to that of the single one?
(b) surface area
(c) surface energy
(d) volume
Solutions : (d) volume

Question 8. Two drops of a liquid merge to form a single drop. In this process energy is
(a) absorbed.
(b) released.
(c) may be absorbed or released depending on the specific heat of the liquid.
(d) neither absorbed nor released.
Solutions : (b) released.

Question 9. What makes it difficult to separate two glass sheets having a drop of water between them?
(a) surface tension
(b) viscosity
(c) gravity
(d) atmospheric pressure
Solutions : (a) surface tension

Question 10. The addition of soap changes the surface tension of water to T1 and that of sugar changes it to T2. Thus
(a) T1 = T2
(b) T1 > T2
(c) T1 < T2
(d) None of the above
Solutions : (c) T1 < T2

Question 11. Water rises ill a capillary tube to a height of h. If the area of cross-section of the tube is made one-fourth, then the water will rise to a height of:
(a) h
(b) h2
(c) 2h
(d) 4h
Solutions : (c) 2h

Question 12. A liquid is flowing uniformly. The net external force causing the liquid to flow is
(a) less than viscosity.
(b) more than viscosity.
(c) equal to viscosity.
(d) not related to viscosity.
Solutions : (c) equal to viscosity.

Question 13. The maximum velocity of the liquid upto which the flow is streamlined does not depend upon
(b) pressure of the liquid.
(c) density of the liquid.
(d) viscosity of the liquid.
Solutions : (b) pressure of the liquid.

Question 14. The velocity upto which the flow of a liquid remains streamlined and above which it becomes turbulent is called
(a) critical velocity.
(b) terminal velocity.
(d) none of the above.
Solutions : (a) critical velocity.

Question 15. One of the major factors that determines the laminar (streamlined) Or turbulent nature of flow of the liquid is
(a) velocity of flow.
(b) pressure of the liquid.
(c) length of the path.
(d) surface tension.
Solutions : (a) velocity of flow.

Question 16. The viscous force does not depend upon
(a) velocity.
(c) nature of the liquid.
(d) area.
Solutions : (a) velocity.

Question 17. In streamlined flow, the velocity of the liquid in contact with the containing vessel is
(a) zero.
(b) minimum but not zero.
(c) infinite.
(d) large.
Solutions : (a) zero.

Question 18. A steadily flowing liquid enters a wide tube and continues to flow steadily. What will be the nature of the tube of flow in the widened part?
(a) widened.
(b) crowded.
(c) will remain as before.
(d) may be crowded or widened.
Solutions : (a) widened.

Question 19. A body is falling freely in a viscous liquid. Finally it:
(a) falls with a constant velocity.
(b) falls with decreasing velocity.
(c) falls with increasing velocity.
(d) comes to rest in the liquid.
Solutions : (a) falls with a constant velocity.

Question 20. Hot syrup flows faster because its
(a) surface tension increases
(b) surface tension decreases
(c) viscosity decreases
(d) viscosity increases
Solutions : (c) viscosity decreases

Question 21. To which type of the fluid is Bernoulli’s theorem strictly applicable?
(a) Viscous
(b) Anisotropic
(c) Compressible
(d) None of the above
Solutions : (d) None of the above

Question 22. Hydraulic brakes work on the basis of:
(a) Poiseuille’s law.
(b) Pascal’s law.
(c) Archemede’s principle.
(d) Bernoulli’s principle.
Solutions : (b) Pascal’s law.

Question 23. Sudden fall in the atmospheric pressure by a large amount shows
(a) rain
(b) fair weather
(c) cloud wave
(d) storm
Solutions : (d) storm

Question 25. 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
Solutions : (c) volume

### Mechanical Properties of Fluids MCQ Questions | mechanical properties of fluids neet mcq pdf

Question: Liquid pressure depends upon
a) height of the liquid column
b) directions
c) shape of the liquid surface
d) area of the liquid surface
Solutions : height of the liquid column

Question: Hydraulic lifts and hydraulic brakes are based on
a) Pascal's law
b) Bernoulli's principle
c) Archimedes' principle
d) Stoke's law
Solutions : Pascal's law

Question: 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

Question: _________ 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
Solutions : Pressure and density

Question: 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
Solutions : transmitted unchanged to every portion of the fluid and wall of containing vessel.

Question: 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
Solutions : area of the bottom surface

Question: Specific gravity of a body is numerically equal to
a) relative density of the body
b) density of body in water
c) weight of the body in water
d) weight of the body in air
Solutions : relative density of the body

Question:  Assertion: A small iron needle sinks in water while a large
iron ship floats.
Reason: The shape of iron needle is like a flat surface while the shape of a ship is that which makes it easier to float.
a) Assertion is correct, reason is incorrect
b) Assertion is incorrect, reason is correct
c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
d) Assertion is correct, reason is correct; reason is a correct explanation for assertion
Solutions : Assertion is correct, reason is incorrect

Question: Consider an iceberg floating in sea water. The density of sea water is 1.03 g/cc and that of ice is 0.92 g/cc. The fraction of total volume of iceberg above the level of sea water is near by
a) 11%
b) 8%
c) 3%
d) 1.8%
Solutions : 11%