# MCQs For NCERT Class 11 Physics Chapter 10 Mechanical Properties of Fluids

Please refer to the MCQ Questions for Class 11 Physics Chapter 10 Mechanical Properties of Fluids with Answers. The following Mechanical Properties of Fluids Class 11 Physics MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 11. Our experts have designed MCQ Questions for Class 11 Physics with Answers for all chapters in your NCERT Class 11 Physics book.

## Mechanical Properties of Fluids Class 11 MCQ Questions with Answers

See below Mechanical Properties of Fluids Class 11 Physics MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. 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.

B

Question. 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

B

Question. The lift of an air plane is based on
(a) Torricelli’s theorem
(b) Bernoulli’s theorem
(c) Law of gravitation
(d) conservation of linear momentum

B

Question. Surface tension may be defined as
(a) the work done per unit area in increasing the surface area of a liquid under isothermal condition
(b) the work done per unit area in increasing the surface area of a liquid under the adiabatic condition
(c) the work done per unit area in increasing the surface area of liquid under both isothermal and adiabatic condition
(d) free surface energy per unit volume

A

Question. A liquid does not wet the sides of a solid, if the angle of contact is
(a) Zero
(b) Obtuse (more than 90°)
(c) Acute (less than 90°)
(d) 90° (right angle)

B

Question. The reading of spring balance when a block is suspended from it in air is 60 newton. This reading is changed to 40 newton when the block is submerged in water. The specific gravity of the block must be therefore
(a) 3
(b) 2
(c) 6
(d) 3/2

A

Question. 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%

B

Question. 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

A

Question. 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

A

Question. 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/

B

Question. A spherical ball of iron of radius 2 mm is falling through a column of glycerine. If densities of glycerine and iron are respectively 1.3 × 103 kg/m3 and 8 × 103 kg/m3. h for glycerine = 0.83 Nm–2 sec, then the terminal velocity is
(a) 0.7 m/s
(b) 0.07 m/s
(c) 0.007 m/s
(d) 0.0007 m/s

B

Question. A cylinder of height 20m is completely filled with water. The velocity of efflux of water (in ms–1) through a small hole on the side wall or the cylinder near its bottom is
(a) 10 m/s
(b) 20 m/s
(c) 25.5 m/s
(d) 5 m/s

B

Question. 8 mercury drops coalesce to form one mercury drop, the energy changes by a factor of
(a) 1
(b) 2
(c) 4
(d) 6

A

Question. Water rises to a height of 10 cm in capillary tube and mercury falls to a depth of 3.1 cm in the same capillary tube. If the density of mercury is 13.6 and the angle of contact for mercury is 135°, the approximate ratio of surface tensions of water and mercury is
(a) 1 : 0.15
(b) 1 : 3
(c) 1 : 6
(d) 1.5 : 1

C

Question. Water flows in a stream line manner through a capillary tube of radius a, the pressure difference being P and the rate flow Q. If the radius is reduced to 2a and the pressure is increased to 2P, the rate of flow becomes
(a) 4Q
(b) Q
(c) Q/2
(d) Q/8

D

Question. A rain drop of radius 0.3 mm has a terminal velocity in air = 1 m/s. The viscosity of air is 8 × 10–5 poise. The viscous force on it is
(a) 45.2 × 10–4 dyne
(b) 101.73×10–5 dyne
(c) 16.95 × 10–4 dyne
(d) 16.95 × 10–5 dyne

D

Question. A big drop of radius R is formed by 1000 small droplets of water. The radius of small drop is
(a) 10/R
(b) 100/R
(c) 500/R
(d) 1000/R

C

Question. 1 m3 water is brought inside the lake upto 200 metres depth from the surface of the lake. What will be change in the volume when the bulk modulus of elastically of water is 22000 atmosphere? (density of water is 1 × 103 kg/m3 atmosphere pressure = 105 N/m2 and g = 10 m/s2)
(a) 8.9 × 10–3 m3
(b) 7.8 × 10–3 m3
(c) 9.1 × 10–4 m3
(d) 8.7 × 10–4 m3

C

Question. There is a hole in the bottom of tank having water. If total pressure at bottom is 3 atm (1 atm = 105 N/m2) then the velocity of water flowing from hole is
(a) √400m/s
(b) √600m/s
(c) √60m/s
(d) None of these

A

Question. 1 centipoise is equal to
(a) 1 kg m–1 s–1
(b) 1000 kg m–1 s–1
(c) 0.1 kg m–1 s–1
(d) 0.001 kg m–1 s–1

C

Question. Two drops of the same radius are falling through air with a steady velocity of 5 cm per sec. If the two drops coalesce, the terminal velocity would be
(a) 10 cm per sec
(b) 2.5 cm per sec
(c) 5 × (4)1/3 cm per sec
(d) 5´ 3 cm per sec

C

Question. In case A, when an 80 kg skydiver falls with arms and legs fully extended to maximize his surface area, his terminal velocity is 60 m/s. In Case B, when the same skydiver falls with arms and legs pulled in and body angled downward to minimize his surface area, his terminal velocity increases to 80 m/s. In going from Case A to Case B, which of the following statements most accurately describes what the skydiver experiences?
(a) Fair resistance increases and pressure P increases
(b) Fair resistance increases and pressure P decreases
(c) Fair resistance decreases and pressure P increases
(d) Fair resistance remains the same and pressure P increases

D

Question. A ring is cut from a platinum tube 8.5 cm internal and 8.7 cm external diameter. It is supported horizontally from the pan of a balance, so that it comes in contact with the water in a glass vessel. If an extra 3.97. If is required to pull it away from water, the surface tension of water is
(a) 72 dyne cm–1
(b) 70.80 dyne cm–1
(c) 63.35 dyne cm–1
(d) 60 dyne cm–1

A

Question. A capillary tube of radius r is immersed in a liquid. The liquid rises to a height h. The corresponding mass is m. What mass of water shall rise in the capillary if the radius of the tube is doubled?
(a) m
(b) 2m
(c) 3m
(d) 4m

B

Question. In a satellite moving round any planet, the gravitational force is effectively balanced. If an ice cube exists there, and it melts with passage of time, its shape will
(a) remain unchanged
(b) change to spherical
(c) become oval-shaped with long-axis along the orbit plane
(d) become oval-shaped with long axis perpendicular to orbit plane

B

Question. An egg when placed in ordinary water sinks but floats when placed in brine. This is because
(a) density of brine is less than that of ordinary water
(b) density of brine is equal to that of ordinary water
(c) density of brine is greater than that of ordinary water
(d) None of these

C

Question. Two pieces of metals are suspended from the arms of a balance and are found to be in equilibrium when kept immersed in water. The mass of one piece is 32 g and its density 8 g cm–3. The density of the other is 5 g per cm3. Then the mass of the other is
(a) 28 g
(b) 35 g
(c) 21 g
(d) 33.6 g

B

Question. A water tank of height 10m, completely filled with water is placed on a level ground. It has two holes one at 3 m and the other at 7 m from its base. The water ejecting from
(a) both the holes will fall at the same spot
(b) upper hole will fall farther than that from the lower hole
(c) upper hole will fall closer than that from the lower hole

A

Question. A fast train goes past way side station platform at high speed. A person standing at the edge of the platform is
(a) attracted to train
(b) repelled from train
(c) unaffected by outgoing train
(d) affected only if the train’s speed is more than the speed of sound

A

Question. Two soap bubbles (surface tension T) coalesce to form a big bubble under isothermal condition. If in this process the change in volume be V and the surface area be S, then the correct relation is (P is atmospheric pressure)
(a) PV + TS = 0
(b) 3PV + 4TS = 0
(c) 3PV + TS = 0
(d) 4PV + 3TS = 0

B

Question. 1 m3 water is brought inside the lake upto 200 metres depth from the surface of the lake. What will be change in the volume when the bulk modulus of elastically of water is 22000 atmosphere?
(density of water is 1 × 103 kg/m3 atmosphere pressure = 105 N/m2 and g = 10 m/s2)
(a) 8.9 × 10–3 m3
(b) 7.8 × 10–3 m3
(c) 9.1 × 10–4 m3
(d) 8.7 × 10–4 m3

C

Question. Work of 3.0 × 10–4 joule is required to be done in increasing the size of a soap film from 10 cm ×6 cm to 10 cm × 11 cm. The surface tension of the film is
(a) 5 × 10–2 N/m
(b) 3 × 10–2 N/m
(c) 1.5 × 10–2 N/m
(d) 1.2 × 10–2 N/m

B

Question. If the terminal speed of a sphere of gold (density = 19.5 kg/m3) is 0.2 m/s in a viscous liquid (density = 1.5 kg/m3), find the terminal speed of a sphere of silver (density = 10.5 kg/m3) of the same size in the same liquid
(a) 0.4 m/s
(b) 0.133 m/s
(c) 0.1 m/s
(d) 0.2 m/s

C

Question. Water is filled in a container upto height of 3m. A small hole of area ‘A0’ is punched in the wall of the container at a height 52.5 cm from the bottom. The cross sectional area of the container is A. If A0/A = 0.1 then v2 is (where v is the velocity of water coming out of the hole)
(a) 50 m2/s2
(b) 50 .5 m2/s2
(c) 51 m2/s2
(d) 52 m2/s2

A

Question. 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