Fluids Questions and Answers

Water in a tank is filled to a depth H whose side walls are vertical A hole is made on one of the walls at a depth h below the free surface of water If R is the distance at which the stream strikes the ground then A R 2h H h B R 2 hH C R 2 H H h D R 2 h H h

A soap bubble in vacuum has a radius of 3 cm and another soap bubble in vacuum has a radius of 4 cm If the bubbles coalesce under isothermal conditions then the radius of the new bubble is 1 2 3 cm 2 4 5 cm 3 5 cm 4 7 cm

At critical temperature the surface tension of a liquid His zero 3 is same as that at any other temperature 2 is infinity 4 cannot be determined

A spherical soap bubble of radius 1 0 cm is formed inside another of radius 2 cm If a single soap bubble is fo which maintains the same pressure difference as inside the smaller and outside the larger bubble the radius c bubble is 1 0 005 m 2 0 05 m 3 0 0067 m 4 0 067 m

3 A capillary tube 1 is dipped in water Another identical tube 2 is dipped in a soap water solution Which of the following shows the relative nature of the liquid columns in the two tubes AIEEE 2008 1 3 B 4 hl 213 sgr asupfue hat water but of Tren

A thin wire is bent in the form of a ring of diameter 3 0 cm The ring is placed horizontally on the surface of som solution and then raised up slowly Upward force necessary to break the vertical film formed between the ring and t solution is 1 6 T dyne 2 2nT dyne 3 4T dyne 4 3T dyne

Two parallel glass plates are dipped partly in the liquid of density d keeping them vertical If the distance betwe the plates is x Surface tension for liquid is T angle of contact is 0 then rise of liquid between the plates du capillary will be 1 Tcose xd 2T cos 0 xdg 3 2T x dgcose 4 Tcose xdg

Water rises in a capillary tube to a height h it will rise to a height more than h 1 on the surface of sun 3 at the poles 2 in a lift moving down with an acceleration 4 in a lift moving up with an acceleration surface of water because

There is a horizontal film of soap solution On it a thread is placed in the form of a loop The film is pierced inside the loop and the thread becomes a circular loop of radius R If the surface tension of the soap solution be T then the tension in the thread will be 1 nR T 2 RT 3 ART 4 2 RT

Three liquids of densities p p2 and p with p p p3 having the same value of surface tension T rise to the same NEET II 2016 height in three identical capillaries The angles of contact 0 0 and 0 obey 1 0 0 0 20 T 3 0 0 0 1 2 0 0 0 0 R 2 TO 4 0 0 0 4cm If the work done is 3 x 104 J the valus

D Water rises in a vertical capillary tube upto a length of 10 cm If the tube is inclined at 45 the length of water column risen in the tube will be RPMT 2003 1 10 cm 3 5 2 cm 10 2 cm 4 20 cm

is tied slightly loose to a wire frame as shown in the figure And the frame is dipped into a soap sor taken out The frame is completely covered with the film When the portion A is punctured with a pin the thread Frame 1 becomes convex towards A 3 remains in the initial position A B Thread 2 becomes concave towards A 4 either 1 or 2 depending on size of A w r t B ricer upto 01m If the same experiment is repeated in an

1 500A 2 5000 A 3 50000 A 4 500000 A The rate of cooling of a sphere of thermal capacity 1000 cal K is 400 J s its rate of fall of temperature i 1 0 095 K min 2 0 62 K min 3 2 8 K min 4 5 7 K min

1 2 rl W trl cost W 3 2 rl cost The radii of the two columns is U tube are r and r When a liquid of density p angle of contact is 0 is filled in it the level difference of liquid in two arms is h The surface tension of liquid is g acceleration due to gravity pghr r 1 2 5 2 pgh r r 21 1 2 3 2 1 1 pghr r 4 pgh 2 1 1 illery tube is

A jet of water with cross section of 6 cm strikes a wa at an angle of 60 to the normal and rebounds elastically from the wall without losing energy If the velocity of the water in the jet is 12 m s the force acting on the wall is 0 864 N 86 4 N 72 N 7 2 N

ue to surface tension the excess pressure inside a smaller drop is 9 units If 27 smaller drops ombine then the excess pressure inside the bigger drop is 4 units B 1 unit C 2 units D 3 units

A large open tank containing water has two holes to its wall A square hole of side a is made at a depth y and a circular hole of radius r is made at a depth 16y from the surface of water If equal amount of water comes out through both the holes per second then the relation between r and a will be 2a r r TU a 2 a 2 T r 2a

metal sphere of radius R density p moves with terminal velocity v through a liquid of nsity o Another sphere of same radius but of density p2 moves through same liquid Its minal velocity will be 0 A P2 V P 0 A 0 V Pl P2 1 0 1 B V D P2 P 0 P 0 V1

If two soap bubbles of radius 2 cm and 4cm respectively are combined in vacuum in isothermal conditions to form a single soap bubble then radius of combined soap bubble is Question Type Single Correct Type 1 2 5 cm 2 5 cm 3 4 3 cm 5 cm

Water rises upto a height h in a capillary tube on the surface of the earth Th value of h will increase if the experimental setup is kept in g acceleration du to gravity a lift going upward with a certain acceleration a lift going down with acceleration a g accelerating train a satellite rotating close to earth

V tal Level A V A Az R2 P P PV P P Pgh P Po fgh P P pg h h P P pgh Activate Windows Go to Settings to activate l Three things fox Venturimer A V A V The P pU P 1 PV P P P VC U P P fgh sir yha pe h1 and h2 us point tk ki kyo nhi liya Activate Wim Go to Settings t iba ne pressure nikalna hai mtlh red point tk

The property of a medium necessary for wave propagation is 1 Its inertia 2 Its elasticity Water wave are 3 Its low resistance Exegy waste il TO 4 All of above resistance move

law for a spherical mem brane derive the expression for the capillary rise of a wetting liquid OR Obtain the relation between surface tension and rise of a liquid in a capillary tube using Laplace s formula for a spherical membrane OR Derive an expression for capillary rise for a liquid having a concave meniscus 3 marks nam and of radius r partiall

An engine pumps water continuously through a hose Water leaves the hose with a velocity v and m is the mas unit length of the water jet What is the rate at which kinetic energy is imparted to water AIPMT 20 2 my 4 m y 1 my 2 1 3 mv 2

A spherical ball is dropped in a long column of viscous liquid The acceleration of ball as a function of time may be best represented by the graph Question Type Single Correct Type 1 2 3 V a F

4 A long cylindrical vessel is half filled with a liquid When the vessel is rotated about its own vertical axis the liquid rises up near the wall If the radius of vessel is 5 cm and its rotational speed is 2 rotations per second then the difference in the heights between the centre and the sides in cm will be a 0 4 b 2 0 c 0 1 d 1 2

surface in terms of interfacial tensions OR Account for the angle of contact in terms of interfacial tensions OR Draw diagram showing force due to surface ten sion at the liquid solid air solid air liquid inter face in case of i a drop of mercury on a plane solid surface and ii a drop of water on a plane Discuss the variation of angle of

57 The shape of impure water meniscus is concave whereas that of mercury meniscus is convex Explain why OR Explain why the angle of contact of mercury with glass is obtuse while that of water with glass is acute 3 marks

1 gram of ice at 0 C is mixed with 1 gram of steam at 100 C At thermal equilibrium the temperature of the mixture is 100 C 55 C 0 C 50 C

19 Consider a plastic cube that has an edge dimension of 20 0 cm and a density of 0 400 g cm placed in a fluid of the density 0 800 g cm What force magnitude and direction is required to keep this cube completely submerged in the fluid

Q A liquid drop of radius R is broken into n identical smaller drops of radius r Find i increase in surface energy ii decrease in temperature of liquid assume increase in surface energy comes from thermal energy of liquid Given T Surface Tension p density of liquid S specific heat capacity of liquid

op 400 m s 2 600 m s 3 60 m s 4 None of these An ice berg of density 900 kg m is floating in water of density 1000 Kg m The percentage of volume of ice cube outside the water is 1 20 2 35 3 10 4 25 log of wood of mass 120 Kg floats in water The weight that can be put on the raft to make it just sink should be

In order that a floating object be in a stable rotation at equilibrium its centre of buoyancy shoul 2 vertically below its centre of gravity 1 vertically above its centre of gravity 3 horizontally in line with its centre of gravity 4 may be anywhere

gl 3 5x5x5x7 gf 4 4x4x4x6 gf Two bodies are in equilibrium when suspended in water from the arms of a balance The mass of one body is 36 its density is 9 g cc If the mass of the other is 48 g its density in g cc is 1 4 3 2 3 2 3 3 4 5 In order that a floating object be in a stable rotation at equilibrium its centre of buoyancy should be

ddo The fraction of a floating object of volume V and density d above the surface of a liquid of density d will be 4 d do M dd 2 d do d What will be the decreasein volume when a mass M of ice melt

Bernoulli s equation is applicable to points 1 in a steadily flowing liquid 2 in a stream line 3 in a straight line perpendicular to a stream line 4 for ideal lequid stream line flow on a stream on is based upon

Blood pressure is measured when the blood is pumping systolic and when the heart is resting diastolic When pressure readings are given the systolic is given first and healthy blood pressure is around 120 over 80 mm Hg Recall the density of mercury is 13 6 x 103 kg m3 a Suppose you have a blood pressure reading of 125 over 75 mm Hg What is your systolic pressure in newtons per meter squared b Suppose you have a blood pressure reading of 125 over 75 mm Hg What is your diastolic pressure in newtons per meter squared

In a turbulent flow the velocity of the liquid molecules in contact with the walls of the tube is 1 Zero 2 Maximum 3 Equal to critical velocity 4 May have any value andi try and ovit

kg 3 7 5 kg Two vessels A and B of different shapes have the same base area and are filled with water up to the same height h figure The force exerted by water on the base is F for vessel A and F for vessel B The respective weights of water filled in vessels are W and W Then

3 2 time that in the other pipe Water enters through end A with speed v and leaves through end B with speed v of a cylindrical tube AB The tube is always completely filled with water In case I tube is horizontal and in case II it is vertical with end A upwards and in case III it is vertical with end B upwards We have v v for 1 Case I 2 Case II 3 Case III 4 Each case ne with a cross sectional area of 4 20 cm The water gradually 10 1 1 4 time that in the other pipe 2

Height of the liquid Air is steaming past a horizontal air plane wing such that its speed in 120 m s over the upper surface and 90 m s at th ower surface If the density of air is 1 3 kg per metre and the wing is 10 m long and has an average width of 2 m the he difference of the pressure on the two sides of the wing of 1 4095 0 Pascal 2 409 50 Pascal 3 40 950 Pascal water Thai 11 30 letale filled in 4 4 0950 Pascal fflux of wntor in m s through a small he

A hemispherical bowl just floats without sinking in a liquid of density 1 2 x 10 kg m If outer diameter and the density of the bowl are 1 m and 2 x 10 kgm respectively then the inner diameter of the bowl will be 3 0 98 m 1 0 94 m 2 0 97 m 4 0 99 m

A rectangular block is 5 cm x 5 cm x 10 cm in size The block is floating in water with 5 em side vertical If it flom with 10 cm side vertical what change will occur in the level of water 2 It will rise 1 No change 3 It will fall 4 It may rise or fall depending on the density of block toal halls is floating on the surface of water in a tank If the ball are thrown into the tank one by

A bot carrying steel balls is floating on the surface of water in a tank If the ball are thrown into the tank on how will it affect the level of water 1 It will remain unchanged 3 It will fall 2 It will rise 4 First it will first rise and then fall then

Air is blown through a hole a closed pope containing liquid Then the pressure will 1 Increase on sides 2 Increase downwards 3 Increase in all direction 4 Never increases

a The viscous force F on a spherical body moving through a liquid depends upon the velocity v of the body the radius r of the body and the co efficient of viscosity n of the liquid Derive the expression for the viscous force by dimensional method

C 5 State Hooke s law On what factors does the modulus of elasticity of a substance depend Define co efficient of viscosity and write down its SI unit What is meant by streamline and turbulent flow of a liquid What is critical velocity 3 1 1 3

The approximate compressibility and density of water is 10 kg m What fractional depth of an ocean is 2700m The of water is 45 4 x 10 Pa compression of water will be obtained at the bottom of the ocean Take g 10ms A 1 2 x 10 2 B C 1 4 x 10 C 0 8 x 10 2 10 x 10 2

The velocity distribution in a viscous flow over a plate is given by u 4y y for y 2m where u is velocity in m s at a point which is at a distance y from the plate If the coefficient of dynamic viscosity is 1 5 in SI units Determine the shear stress at y 0 in N m

A thin walled glass tube of radius 0 5 cm is dipped vertically in the water of surface tension 70 dyne cm The force required to take it out from the water is Mark for review later 44 10 5 N O 44 x 104 N 4 O 2 4 10 4 N O 0 44 x 10 6 N