Fluids Questions and Answers

An iron block and a wooden block are positioned in a vessel containing water as shown in the figure The iron block 1 hangs from a massless string with a rigid support from the top while the wooden block 2 floats being tied to the bottom through a massless string If now the vessel starts acceleration towards right A iron block gets deflected towards right C iron block gets deflected towards left W B wooden block gets deflected towards right D wooden block gets deflected towards left

ind the wrong statement among the following Surface tension of liquid is independent of area of surface Water with detergent dissolved should have small angle of contact Centre of a spinning cricket ball in air does not follow parabolic trajectory For a fluid in steady flow increase of fluid speed at a constriction follows conservation of momentum law

train and the tunnel walls is p then Po P NPV The value of N is 2N 9 PV Train Po 4S V 3S V V Apply bernoulli s theorem Po 2 PV P 12 PV Po P PV 18 V

A solid cone of uniform density and height 2R and base radius R has a conical portion scooped out from its base with the same base radius but height R as shown in the figure The solid cone is floating in a liquid of density p with vertex A touching the fluid surface If atmospheric pressure is Po the force acting on the surface BCD due to liquid is TR pg 3P R pg 3 B A 3 TR 9 2 Rpg 3P 1 TR p pg 5 3P Rpg 4 3Po 2R

A liquid of specific gravity 0 58 is filled in a large container shown in figure Area of cross section of tube is negligible as compare to the area of cross section of container then the magnitude of gauge pressure at point A is given by X atm then x is 20 A 1m 3m

Find the wrong statement among the following Surface tension of liquid is independent of area of surface Water with detergent dissolved should have small angle of contact Centre of a spinning cricket ball in air does not follow parabolic trajectory For a fluid in steady flow increase of fluid speed at a constriction follows conservation of momentum law

area A having a liquid of mass M and density p If the liquid in the column is slightly displaced then it oscillates with a time period of acceleration due to gravity g P U M AT 2T g BT 27 CT 2T DT2T MA gp M Apg M 2 Apg Solution D If the level of liquid is depressed by y in column Q then the level of liquid in column P will be 2y higher than the liquid level in column Qas shown in the figure P 2y UL Let m be the mass of increased height of liquid column in P The weight of extra liquid in the column W mg pVg A 2y pg This will act as the restoring force on the entire liquid column i e Fr 2 Aypg Acceleration a 2 Aypg M

Radius of a bubble at the bottom of the tank shown below was found to be 2 cm Find the radius of the bubble at the surface of water at the same temperature 10 336 metre 01 51 cm 2 51 cm 01 414 cm C2414 cm 10 336 metre

12 Water rises to a height of 16 3 cm in a capillary of height 18 cm above the water level If the tube is cut at a height of 12 cm 1 Water will come as a fountain from the capillary tube 2 Water will stay at a height of 12 cm in the capillary tube 3 The height of the water in the capillary will be 10 3 cm 4 Water will flow down the sides of the capillary tube

A tank is filled with immiscicible liquid of two different densities p and 2p upto height 2H metre as shown in figure An orifice is created at the bottom Find efflux velocity 1 2gH www H 2p 2 3gH A 16aH

An ice block floats in a liquid whose than water A part of block is outside the liquid When whole ice has melted the liquid level will 1 Rise 2 Go down 3 Remain same

Find the pressure of gas inside the container if the manometer attached to the container shows a difference of 40 mm as shown in the figure of 1 05 atm 2 05 atm 3 05 atm None of these 40 mm Hg

Two spheres of volume 250 cc each but of specific gravities 0 8 and 1 2 are connected by string and the combination is immersed in water at equilibrium The tension in the string will be g 10 m s 5 N 0 5 N 1 N 2 N

Q 19 20 are based on the following situation A large tank is filled with water density 10 kg m to a height H A small hole is made at a depth 10 m below water surface The range of water issuing out of the hole s R on ground take 1 atm 105 Pa and g 10 m s 19 20 R What extra pressure must be applied on the water surface so that the range becomes 2R 1 atm 105 Pa and g 10 m s A 2 atm B 3 atm C 8 atm D 9 atm TOAT After this xtra pressure is applied at what height a hole should be made so as to get a maximum range on t ground A at a height H 2 B at a height above H 2 C at a height less than H 2 D The range is same for any height of the hole

A glass tube of length L and cross section A filled with a liquid of density p is being rotated about one end abou vertical axis with an angular speed oo The pressure difference between the two walls of the tube is A p w L B p L 2 C p wL D p L 2

c Figure shows top view of an airplane blo by wind and magnitude of velocity of wind to be same in each case VA w velocity of airplane relative to wind Vw g velocity of wind in ground frame Then which is not correct a 90 120 Vw g b wig d VA W Bond 60 30 VA We N S a Airplane travels fastest across ground in case d b Airplane travels slowest across ground in case a c Airplane experiences maximum lateral displace in case a E 35 36 W

A cylindrical tank with a large diameter is filled with water to a depth D 0 256 m A hole of cross sectional area A 5 94 cm in the bottom of the tank allows water to drain out a What is the ate at which water flows out in cubic meters per second b At what distance below the bottom of the tank is the cross sectional area of the streamn equal to one half the area of the hole a Number 5 3 b Number Units Units

A body is floating in the liquid with 40 of its volume outside the liquid When entire system is accelerated downward with an acceleration g 4 then the percentage of its volume inside the liquid will be 1 40 3 60 2 50 4 70

A capillary tube of radius is immersed in water and water rises in it to a height H Mass of water in the capillary tube is m If the capillary of radius 2r is taken and dipped in water then the mass of water that will rise in the capillary tube will be

A bent tube is lowered into a water stream as shown in figure 7 57 The velocity of the stream relative to the tube is equal to v 2 5 m s The closed upper end of the tube located at the height 12 cm has a small orifice To what heighth will the water jet spurt 111 SH ho

Water rises to a height h in a capillary tube held vertically in a beaker containing water If the capillary tube is inclined at an angle 30 with the water surface the length to which water rises in the capillary will be

45 Derive the relation between the surface tension and surface energy of a liquid OR Derive the relation between surface tension and OR surface energy per unit area Show that the surface tension of a liquid is numerically equal to the surface energy per unit 2 marks film is isothermally stretched over area

A ball floats on water but will sink when put into mineral spirits mineral spirit is immiscible in water If the mineral spirits is poured slowly on top of the water while the ball is floating on the water what will happen to the level at which the ball floats 1 The ball will float lower into the water 2 The ball will float higher out of the water 3 The ball will float at the same level with respect to the surface of the water after the mineral spirits are poured on top of the water 4 The ball will sink to bottom of water

A B Speed of B just after the impulse imparted is 7m IOJ 7m 3 J C Speed of C just after the impulse imparted is 7m 4 22 2J D Speed of A just after the impulse imparted is 7m A liquid of density p comes out with a velocity V from a horizontal tube of area c cross section A The reaction force exerted by the liquid on the tube is f then D fx p A fx V B fx V C fx A Consider the case standing waves setup in an organ pipe of length 1 Case i closed pipe Case ii open pipe A All possible harmonic are heard in the open pipe

A semi circular vertical plate is partially submerged in the water with 6 meters diameter What is the force on the plate due to hydrostatic pressure if the water level is 1 meter from the top of the plate Set up also the integral

MePhIT BOT Today at 6 14 PM 7 A 73kg man with a density of 1 10g cm 3 ages He gains 5 5kg of fat Will he float 1 No he won t His specific gravity is 1 023 2 Yes he will His specific gravity is 0 94 3 Yes he will His specific gravity is 0 99 4 No he won t His specific gravity is 1 18

3 Calculate the pressure drop in mmHg across the following arterial systems using Poiseuille s Law with n blood 4 10 3 Pa s for a total flow of 80cm 3 s 1 across large arteries internal radius r 0 2cm length L 73cm n 200 of them each with equal flow and the same dimensions 1 190 76Pa 2 190 98Pa 3 185 89Pa 4 189 5Pa 2 1 3 1 4 1

14 When water is filled carefully in a glass one can fill it to a height h above the rim of the glass due to the surface tension of water To calculate h just before water starts flowing model the shape of the water above the rim as a disc of thickness h having semicircular edges as shown schematically in the figure When the pressure of water at the bottom of this disc exceeds what can be withstood due to the surface tension the water surface breaks near the rim and water starts flowing from there If the density of water its surface tension and the acceleration due to gravity are 10 kg m 0 07 Nm and 10 ms 2 respectively the value of h in mm is 14 ALLEN CAREER INSTIT COVEGAMENTO Ans 3 74 Sol h 2 r h 2 Pressure at the bottom of disc pressure due to surface tension pgh T 1 1 R R JEE Advanced 2020 Paper 1 Held on Sunday 27 September 2020 R R 1 1 So R R Pgh TR R2 T 04 2 and R h 2 JEE Advanced 2020 Paper 1 NAT

A common hydrometer has a uniform stem graduated downwards from 0 1 2 upto 10 when floating in pure water it reads 0 and in a liquid of relative density 1 5 it reads 10 What is the relative density of a liquid in which it reads 57 A 1 20 C 1 30 B 1 25 D 1 15

1 When a capillary tube is dipped in a liquid the liquid rises to a heighth in the tube The free liquid surface inside the tube is hemispherical in shape The tube is now pushed down so that the height of the tube outside the liquid is less than h Then the a liquid will come out of the tube like in a small fountain b liquid will ooze out of the tube slowly c free liquid surface inside the tube is hemispherical d the liquid will fill the tube but not come out of its upper end

eater than 90 81 A soap bubble formed at the end of the tube is blown very slowly The graph between excess of pressure inside the bubble with time is PA a c P4 b d PA

A tank is filled upto a height h with a liquid and is placed on a platform of height h from the ground To get maximum range xm a small hole is punched at a distance of y from the free surface of the liquid Then 1 xm 3h Question Type Single Correct Type 2 xm 1 5h h 3 y h K

3 A submarine called the DeepView 66 is currently being developed to take 66 tourists at a time on sightseeing trips to tropical coral reefs According to guidelines of the American Society of Mechanical Engineers ASME to be safe for human occupancy the DeepView 66 must be able to withstand a pressure of 10 0 N per square millimeter To what depth in m can the DeepView 66 safely descend in seawater if the density of seawater is 1025 kg m 3

A metallic wire of density p floats horizontally in water The maximum radius of the wire so that the wire may not sink will be surface tension of water T and angle of contract 0 2T 4T A B g pg T g C D ALA TP To

A cylinder of height 30 cm and radius 7 cm is immersed completely in a fluid of density 1 3x10 kg m What is the buoyant force acting on it Take g 10 m s a 100 N b 40 N c 21 N d 60 N

69 The flow rate of water from a tap of diameter 1 25 cm is 3 L per min The coefficient of viscosity of water is 10 3 Pa s The nature of the flow is b Turbulent d None of these a Unsteady c Laminar

12 An intravenous infusion is made under gravity If the fluid to be delivered has a density of 1 06 g cm 3 at what height above the vein h should the top surface of the fluid in the bottle be positioned so the fluid just barely enters the vein The gauge pressure in the vein is 18mmHg Assume the needle entering the vein has a large inside diameter 1 h 23 8cm 2 h 24 0cm 3 h 23 0cm 4 h 23 1cm 12 21 3 1 1

The radius of a small oil drop falling in air is xx10 6m with a terminal velocity of 1mms X Find x Given specific gravity of oil 0 900 and n of air 1 8x10 5 decapoise Neglect the ongits

D A solid body floating in water has of its 5th volume immersed in it What fraction of its volume will be immersed if it floats in a liquid of specific gravity 1 2 a th 6 b th 5 c th 5 5 d th 6

ent data 63 Eight drops of water each of radius 2 mm are fall through air at a terminal velocity of 8 cm s If the coalesce to form a single drop then the termin velocity of combined drop will be a 32 cm s b 30 cm s 1 d 24 cm st c 28 cm s A drop of water of radius 0 0015 mm ic

7 A 79kg man with a density of 1 09g cm 3 ages He gains 5 3kg of fat Will he float 1 No he won t His specific gravity is 1 16 2 No he won t His specific gravity is 1 23 3 No he won t His specific gravity is 1 023 4 Yes he will His specific gravity is 0 99 2 1 3

64 A drop of water of radius 0 0015 mm is falling in a the coefficient of viscosity of air is 2 0 x 10 kgm the terminal velocity of the drop will be The density of water 10 kg m and g 10ms a 1 0 x 10m s b 2 0 x 10ms d 5 0 x 10ms c 2 5 x 10 ms

h near the the Shearing bottom layer Pas MEG Objective NCERT P v If a bal 8M of same metal into a column of glycerme terminal velocity of the ball will be a 2v b 4v c 8v d of m

c Torricelli s law d Relative density 68 For turbulent flow the value of Reynolds number is a R 2000 b R 2000 c 1000 R 2000 d R 1000 69 The flow rate of water from a tap of diameter 1 25 cm

c 0 005 m d 0 0005 m 57 A gas bubble of 2 cm diameter rises through a liquid of density 1 75 gm cm with a fixed speed of 0 35 cm s Neglect the density of the gas The coefficient of viscosity of the liquid is b 1120 poise d 1089 poise 58 a 870 poise c 982 poise dro of 3

A U Tube contains two liquids in static equilibrium Water in right arm and oil of unknown density in left arm Measurement given are 136 mm and d 12 mm the density of oil is oil interface www aaa www 919 kg m 3 712 kg m 629 kg m 810 kg m water

What is the net upward force on an airplane wing of area 17 2 m if the speed of air flow is 302 m s across the top of the wing and 279 m s across the botto 143652 N

c 9 6 x 10 m d 3 6 x 10 m 33 In the figure shown an ideal liquid is flowing through the tube which is of uniform area of cross section The liquid has velocities v and vg and pressures P and P at points A and B respectively Then B a vv b v v c P P d P P 40

b Bernoulli d Torricelli PRESSURE 1 Pressure applied to an enclosed fluid is transmitted undiminished to every point of the fluid and the walls by of containing vessel This law was first formulated 7 Two syringes of different cross section wat needle filled with water are connected with a tigh the smaller piston and larger piston are 1 cm an fitted rubber tube filled with water Diameters 3 cm respectively If a force of 10 N is applied to the smaller piston then the force exerted on the large a Reynolds c Pascal piston is a 30 N b 60 N c 90 N d 100 8 In question number 7 if the smaller piston is pushe in through 6 cm how much does the longer piston move out 2 Which of the following conversions is correct a 1 atm 1 01 x 10 Pa b 1 mm of Hg 133 Pa c 1 bar 107 Pa d 1 torr 10 Pa 3 Pressure is a scalar quantity because a it is the ratio of force to area and both force and area are vectors b it is the ratio of the magnitude of the force to area c it is the ratio of the component of the force normal to the area d it depends on the size of the area chosen 4 Pressure at a point inside a liquid does not depend on a the nature of the liquid b shape of the container c the depth of point below the surface of the liquid d acceleration due to gravity at that point The two femurs each of cross sectional area 10 cm support the upper part of a human body of mass 40 kg The average pressure sustained by the femurs is Take g 10 m s a 2x 10 Nm c 2 x 10 Nm b 2x 10 Nm d 2 x 10 N m pressure exerted by the heel on is Take g 10 ms 2 a 6 4 x 10 Pa c 6 4 x 10 Pa A 50 kg girl wearing heel shoes balances on a single heel The heel is circular with a diameter 1 cm The cm cm c cm cm 9 To what height should a cylindrical vessel be filled with a homogeneous liquid to make the force with which the liquid pressure on the sides of the vesse equal to the force exerted by the liquid on the bottom of the vessel a Equal to the radius c More than radius a 0 6 Water 10 A U tube contains water and methylated spirt separated by mercury The mercury columns in the two arms are at the same level with 10 cm of water in one arm and 12 5 cm of spirit in the other as shown in figure The relative density of the spirit is Down b 0 8 10 cm the horizontal fo b 6 4 x 10 Pa d 6 4 10 Pa b Less than radius d Four times of radius 12 5 cm EXCHGHES c 1 0 Spirit Mercury d 1 25

A thread is tied slightly loose to a wire frame as shown in figure The frame is dipped in soap solution and taken out The frame is completely covered with the film When the portion A is pricked with a pin the thread Option A B C becomes concave towards A becomes convex towards A remains in original position Rate this questic