Fluids Questions and Answers

4 A vessel with water is placed on a weighing pan and it reads 600 g Now a ball of mass 40 g and density 0 80 g cm3 is sunk into the water with a pin of negligible volume as shown in figure keeping it sunk The weighing pan will show a reading a 600 g b 550 g 650 g 632 g c d Weighing pan 2020

The velocity of liquid v in steady flow at a location through cylindrical pipe is given by Vol 1 R where r is the radial distance of that location from the axis of the pipe and R is the inner radius of pipe If R 10 cm volume rate of flow through the pipe is n 2 x 10 m s and the coefficient of viscosity of the liquid is 0 75 N sm 2 find the magnitude of the viscous force per unit area in Nm 2 at r 4 cm

A carpenter hits a nail with a 50 N force The area of the nail head is 2 5 x 10 5 m2 The area of the pointed end of the nail is 2 5 x 10 7 m2 What is the pressure applied by the pointed end of the nail a 2x10 6 N m2 b 2x10 8 N m2 c 0 00125 N m2 d 1 25x10 5 N m2 e 2x10 9 N m2

23 In a large rectangular water tank water is coming out of a small hole at the bottom of the tank It takes almost 5 minute to empty half of the tank How much further time approximate will be needed to empty the tank completely 1 12 minute 2 6 minute 3 10 minute 4 8 minute

Given density of ball p 2p and density of liquid p p The acceleration of the ball is g Solid Ball 22 a g Find the value of M N

Figure shows a siphon Choose the wrong statement Po atmospheric pressure O Siphon works when h3 0 O Pressure at point 2 is P2 Po pgh3 O Pressure at point 3 is Po O Pressure at point 1 is Po h 0 OPPFOK 0 hoode www CCCCCCCC P K

1 English While measuring the surface tension of a liquid by a capillary of non uniform bore its radius should be measured Question Type Single Correct Type at the lower end dipped in liquid 2 at the upper end open in air 4 Review 3 by taking mean of the radii at the two ends by cutting the capillary at the point up to which the liquid rises in the capillary

dius r ake to find equal ing 9 h Which of the following figure shown below A 1 V V 0 A 20Q A R h 2 S 3A 4 for the 25 TA TO 2 PQ Psoria

mple 24 A square glass plate of length 10 cm and thickness 0 4 cm weighs 40 g in air It is held vertically such that its lower edge rests on water surface What is the apparent weight of glass plate now Given surface tension of water 0 073 N m

Consider the open topped tank below It is filled with a non compressible 0 viscosity fluid The plug at bottom is removed what is the fluid velocity of the fluid coming out of the spout v H P v h H P2 V h 0

An object of density d kept deep inside water of density d and released During the time it moves a vertical distance h with in the water AU A The gravitational B The gravitational potential energy of the water in the vessel decreases if d d C The gravitational potential energy of the object increases if d d D The gravitational potential energy of the object decreases if d d Statement 1 When a body floats such that it s parts are immersed into two immersible liquids then force exerted by liquid 1 is of magnitude Pivg Statement 2 Total Buogyant force P V 8 P 28 A Statement 1 is true statement 2 is true and statement 2 is correct explanation for statement 1 B Statement 1 is true statement 2 is true and statement 2 is NOT the correct explanation for statement 1 C Statement 1 is true statement 2 is false pe of body body 1 SUPE GUPT 2 S P

A spherical ball of radius r and relative density 0 5 is floating in equilibrium in water with half of it immersed in water The work done in pushing the ball down so that whole of it is just immersed in water is where p is the density of water a 5 12 pi r 4 rho g b 0 5prg c 4 3 pi 3 rho g d

P27 A circular hole of radius r at the bottom of an initially full water container is sealed by a ball of mass m and radius R r The depth of the water is now slowly reduced and when it reaches a certain value ho the ball rises out of the hole Find ho m E R ho

A tank 5 m high is half filled with water and then is filled to the top with oil of density 0 85g cm The pressure at the bottom of the tank due to these liquids is A 1 85gdyne cm

An incompressible gas flows steadily through a pipe of unknown possibly variable cross sectional area Three small holes are drilled into the pipe at locations a b c and a manometer containing a blue liquid is connected to each hole The resulting liquid levels are shown in the figure Rank the gas speed in the pipe at points a b c from highest to lowest Flow O a b c O c b a O all are equal O b a c O a c b Liquid b Flow

19 If water is flowing in a pipe with speed 2 m s then its kinetic energy per unit volume is 1 500 J m 2 1000 J m 3 1500 J m 4 2000 J m a thon terminal speed into a viscou

22 Two co axial glass tubes forming an annulus with small gap are immersed in clean water The inner and outer radii of the annulus are r and r respectively What is the capillary rise of water in the annulus if o is the surface tension of water is constant with air p is the density of water and g acceleration due to gravity a b 20 pg ro r 46 80 pg ro ri

Elasticity 9 If water is flowing in a pipe with speed 2 m s then its kinetic energy per unit volume is 1 500 J m 2 1000 J m 3 1500 J m 4 2000 J m terminal speed into a viscous li

A cylindrical vessel of thickness 2 cm floats in a liquid as shown in figure With a depth of 8 cm immersed the vessel develops a leak in its bottom What should be the minimum height of the vessel so that it may not sink D 16 cm

Question Calculate the pressure in the hose whose absolute pressure is 1 01 x 105 N m 2 if the speed of the water in the hose increases from 1 96 m s 1 to 25 5 m s 1 Assume that the flow is frictionless and density 103 kg m 3

Water of density p in a clean aquarium forms a meniscus as illustrated in the figure Calculate the difference in height h between the centre and the edge of the meniscus The surface tension of water is Y A 2y pg Y pg C B Vpg Y D 2 2 TE pg

A column of mercury of length h 10 cm is contained in the middle of a narrow horizontal tube of length 1 m closed at ends The air in both halves of the tube is under a pressure of P 76 cm of mercury The tube is now slowly made vertical The distance moved by mercury will be 1 4 5 cm 2 3 0 cm 3 2 5 cm 4 1 2 cm

Cross sectional area of tube at A and B are 4 cm and 2 cm respectively If speed of ideal liquid flowing in this tube at point A is 10 m s then speed of liquid at point B will be m s A B Answer 00 01 02 03 04 05 06 07 08 09 05 6 07

A solid hemisphere of radius R is immersed into a liquid c density p If the hemisphere is at a depth 2R then force exerted by liquid on the flat surface of hemisphere is Po atmospheric pressure 2R R P 3pRg P 2 pRg OTR Po O R Po 2pgR

cubic pool that has the edges of L is being filled by the water Water is described by the vector J vater described by the flow vector J below J r y 2J ryi y j z k with Jo having the appropriate units Find the units for Jo Find the time to fill the pool if at 0 the pool is empty

An aquarium window of dimensions 4 m by 2 m is built 0 5 m below the surface of the water How large a force is exerted by the water on the window due to water pressure The density of water is 1000kg m 2 90 104 N 5 47 104 N O 2 02 104

A long capillary tube of radius r is put in contact with surface of a perfectly wetting liquid of density p and very low viscosity What maximum height h the liquid can rise inside the capillary Here height is measured above the level of the liquid outside the capillary Surface tension of the liquid and acceleration due to gravity are denoted by a and g respectively a h c 20 pgr 20 pgr h 40 pgr 40 pgr d Insufficient information b h

When completely immersed in water 6 gm of iron and certain quantity of lead are found to have the same weight If the densities of iron and lead are 8 gm cc and 11 gm ce respectively the mass of lead is nearly A 4 2 gm B 5 8 gm

A solid uniform ball having volume V and density p 2 10 kg m floats at the interface of two immiscible liquids as shown in the figure The densities of the upper and the lower liquids are p 1 5x 10 kg m and P 2 5 10 kg m respectively The fraction of the volume of the ball in the upper liquid is 1 x Then x is equal to

3 1 English Mark for review A uniform heavy plate is held horizontal resting symmetrically on two frictionless pistons each of which is placed in the opening of a symmetric U tube filled with an incompressible fluid as shown in the figure Once the restraints on the plate are released then A A A A TU Question Type Single Correct Type 1 piston A will rise and A2 will fall 2 piston A2 will rise and A will fall 3 the plate will remain level and not move

A capillary tube of radius r is placed inside the water of density po as show Liquid rises in the tube to the level H Consider a point A just below the to surface of water as shown Point B a small pin hole is at the depth of from top surface If P is atmospheric pressure then choose correct statements INVIDEMKNIE I 00000 m A PA Po B If a small hole is made in the capillary tube at B then speed of liqui coming out of the capillary tube will be V 2g 29 H 2 C Pressure at B inside the capillary tube will be Po Pog H

A body floats in water in a beaker such that 1 3rd of its volume is out side the water The beaker is placed in a lift which moves up with an acceleration The fraction of volume of the body immersed in water is A 6 B 3 4 c

2 gm cc and 3 gm cc are taken in three identical vessels The ratio of forces on the base of the vessels is A 1 2 3 B 6 3 2 C 1 1 1 D 3 2 1 Mark For Review Next Save Next Clear Response Submit PHYSICS 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

A uniform cylindrical rod of mass m and density pois having a point mass m at its bottom end The complete arrangement is just found to be in stable equilib rium at the position shown in diagram The value of ratio of density of liquid to that of rod under the given condition is w

Two soap bubbles of radii R and 2R in vacuum coalesce under isothermal conditions The radius of the new bubble is surface tension of soap solution is 2 5 10 N m Options 1 2 3R 5R

A small spherical object having density 2p is placed inside the liquid of density o and connected to an ideal string of length whose other end is kept fixed so that the object can move in a vertical circle Find minimum speed in m s which must the given at the bottom to just complete the vertical circle Ignore viscosity or any such other drag forces g 9 8 m s 2m

A cylindrical rod A p L are cross sectional area density and length of roc respectively having a point mass 2m m ApL at its bottom then choose correct alternative s A p L A Rod is in rotational stable equilibrium B Rod is in rotational unstable equilibrium C Rod is in rotational neutral equilibrium D Rod is in translational unstable equilibrium along vertical direction

Two immiscible liquid of densities p and 3p are put in a container The height of each liquid is h A solid cylinder of length L and density d is put in this container The cylinder floats completely inside liquids with its axis vertical and length in the denser liquid The density d is equal to 1 3 5p 2p 2 3p 5 4 4p

Two identical containers contains liquid of same mass m but different densitie as shown in the figure given p P P and P are pressures at the bottoms c the container 1 and container 2 respectively and F and F are the force exerted by the liquid on the walls of container 1 and container 2 respectively Neglect the atmospheric pressure A P P 1 B P P C F F D F F Container 1 P Container 2

A liquid of density p pushes the vertical plate of the gate towards the right Match the following column A B C D C Column l Force on the vertical gate due to the liquid Force on the horizontal plate due to the liquid Force on the triangle 1 due to the liquid Force on the triangle 2 due to the liquid SECTION C P Q R S Column II 1 3 pgbh 1 6 6pbh 1 2 pgbh pghbc

An object is fitted in a hole at base of a container as shown in figure the force due to liquid on offect is Assume no leakage of water volume of object inside container is V and density of liquid is p 2

upvote Question 7 Consider a business jet like the Gulfstream G550 flying at a standard altitude of 30 000 ft and V 525 mph Assuming inviscid incompressible flow calculate the pressure measured by the Pitot tube Question 7 options PO 1157 74 lb ft Po 264 04 lb ft Po 630 00 lb ft 883 70 16 4 2

4 An 8kg plastic block with a specific volume of 5 69x10 4 m is fully submerged in water while kg attached to a rope What is the tension force on the rope 71 LJ

in its vertical wall as of side L at a depth hole of radius R at apletely filled with second from both C 7 5 In the figure shown 7 74 water is filled in a symmetrical container Four pistons of equal area A are used at the four opening to keep the water in equilibrium Now an additional force each of magnitude F is applied at each piston The increase in the pressure at the centre of the container due to this addition is F A 4F A wwwwww F2 Figure 7 74 B 2F A D 0

ure 7 73 It is filled closed Then the B will be the radius of the section A 040 1 A 7 7 A U tube of base length 7 filled with same volume of two liquids of densities p and 2p is moving with an acceleration a on the horizontal plane If the height difference between the two surfaces open to atmosphere becomes zero then the height h is given by a l A 28 C 91 A Figure 7 75 L 3a 2g c 201 A 3 0 Y 7 11 setup h nozzle is rotat rotation

7 9 A non uniform cylinder of mass m length and radius ris having its centre of mass at a distance 1 4 from the centre C and lying on the axis of the cylinder The cylinder is kept in a liquid of uniform density p The moment of inertia of the rod about the centre of mass is I The angular acceleration of point A relative to point B just after the rod is released from the horizontal position shown in figure 7 77 is C A pg 2 I C pgl r 21 A C CM K 114 Figure 7 77 B D B pgl 2 41 3 pg 1 41 sibeln 60

By sucking through density 13 6 g cm 1 13 6 cm 2 1 36 cm 3 0 136 cm 10 cm a straw a boy can reduce the pressure in his lungs to 750 mm of Hg Using a straw he can drink water from a maximum depth of

0 012m and relative density 2 0 is free to rotate about O in vertical plane The rod is held with a horizontal string AB which can withstand a maximum tension of 45N The rod and string system is kept in water as shown in figure 7 80 The maximum value of angle a which the rod can make with vertical without breaking the string is Take g 10 m s A 45 C 53 A a B Figure 7 80 B 37 D 60 Fixed vessel F

as well As the 7 21 A copper piece of mass 10 g is suspended by a vertical spring The spring elongates 1 cm over its natural length to that of keep the piece in equilibrium A beaker containing water is now placed below the piece so as to immerse the piece completely in water Find the approximate elongation of the spring Density of copper 9000 kg m Take g 10 m s A 0 45cm B 0 89cm C 1 02cm D 1 86cm with with

7 27 A cylindrical wooden float whose base area S and the height H drifts on the water surface Density of wood d and density of water is p What minimum work must be performed he to take the float out of the water ac ho att A C S gd 2p Sgd H 2p B D Sgd H P 2S gd PH C