An incompressible liquid flows through a horizontal tube as shown in the following fig. Then the velocity v of the fluid is

 

 

  •     3.0 m/s                          

  • 1.5 m/s                     

  • 1.0 m/s                             

  • 2.25 m/s

The velocity of kerosene oil in a horizontal pipe is 5 m/s. If g=10m/s2, then the velocity head of oil will be:

  • 1.25 m
  • 12.5 m
  • 0.125 m                             
  • 125 m

In the following fig. is shown the flow of liquid through a horizontal pipe. Three tubes A, B and C are connected to the pipe. The radii of the tubes A, B and C at the junction are respectively 2 cm, 1 cm and 2 cm. It can be said that the

 

 

  • () Height of the liquid in all the three tubes is the same

  • () Height of the liquid in the tubes A and C is the same

  • () Height of the liquid in the tube A is maximum

  • () Height of the liquid in the tubes A and B is the same

A manometer connected to a closed tap reads 3.5×105 N/m2. When the valve is opened, the reading of manometer falls to 3.0×105 N/m2 , then velocity of flow of water is

  • 100 m/s                                       

  • 10 m/s

  • 1 m/s                                           

  •  1010 m/s

A cylinder of height 20 m is completely filled with water. The velocity of efflux of water (in m/s) through a small hole on the side wall of the cylinder near its bottom is

  • 10                                       

  • 20

  • 25.5                                     

  • 5

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) 400  m/s             (b) 600  m/s

(c) 60  m/s                (d) None of these

 

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An incompressible liquid travels as shown in the figure. The speed of the fluid in the lower branch will :

  • 1 m/s

  • 1.5 m/s

  • 2.25 m/s

  • 3 m/s

A cylindrical tank has a hole of 1 cm2 in its bottom. If the water is allowed to flow into the tank from a tube above it at the rate of 70 cm3/sec. then the maximum height up to which water can rise in the tank is

  • 2.5 cm                                             

  • 5 cm

  • 10 cm                                               

  • 0.25 cm

A square plate of 0.1 m side moves parallel to a second plate with a velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 poise, distance between the plates in m is

  • 0.1                             

  • 0.05

  • 0.005                         

  • 0.0005

Spherical balls of radius 'r' are falling in a viscous fluid of viscosity 'η' with a velocity 'v'. The retarding viscous force acting on the spherical ball is 

  • inversely proportional to 'r' but directly proportional to velocity 'v'.

  • directly proportional to both radius 'r' and velocity 'v'.

  • inversely proportional to both radius 'r' and velocity 'v'.

  • directly proportional to 'r' but inversely proportional to 'v'.

A small sphere of mass m is dropped from a great height. After it has fallen 100 m, it has attained its terminal velocity and continues to fall at that speed. The work done by air friction against the sphere during the first 100 m of fall is

  • Greater than the work done by air friction in the second 100 m

  • Less than the work done by air friction in the second 100 m

  • Equal to 100 mg

  • Greater than 100 mg

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)13 cm per sec                          (d) 5×2 cm per sec

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The rate of steady volume flow of water through a capillary tube of length 'l' and radius 'r' under a pressure difference of P is V. This tube is connected with another tube of the same length but half the radius in series. Then the rate of steady volume flow through them is (The pressure difference across the combination is P)

  •  V16                                     

  •  V17

  •  16V17                                   

  •  17V16

A liquid is flowing in a horizontal uniform capillary tube under a constant pressure difference P. The value of pressure for which the rate of flow of the liquid is doubled when the radius and length both are doubled is

(a) P                             (b) 3P4

(c) P2                           (d) P4

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We have two (narrow) capillary tubes T1 and T2. Their lengths are l1 and l2 and radii of cross-section are r1 and r2 respectively. The rate of flow of water under a pressure difference P through tube T1 is 8cm3/sec. If l1 = 2l2 and r1 =r2, what will be the rate of flow when the two tubes are connected in series and pressure difference across the combination is same as before (= P)

(a) 4 cm3/sec                           (b) (16/3) cm3/sec

(c) (8/17) cm3/sec                    (d) None of these

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The Reynolds number of a flow is the ratio of

  • Gravity to viscous force

  • Gravity force to pressure force

  • Inertia forces to viscous force

  • Viscous forces to pressure forces

Water is flowing through a tube of non-uniform cross-section. Ratio of the radius at entry and exit end of the pipe is 3 : 2. Then the ratio of velocities at entry and exit of liquid is -

  • 4 : 9                         

  • 9 : 4

  • 8 : 27                         

  • 1 : 1

A liquid flows in a tube from left to right as shown in figure. A1 and A2 are the cross-sections of the portions of the tube as shown. Then the ratio of speeds v1/v2 will be

  •  A1/A2

  •  A2/A1

  •  A2/A1

  •  A1/A2

An application of Bernoulli's equation for fluid flow is found in 

  • Dynamic lift of an aeroplane

  • Viscosity meter

  • Capillary rise

  • Hydraulic press

The Working of an atomizer depends upon

  • Bernoulli's theorem                 

  • Boyle's law

  • Archimedes principle               

  • Newton's law of motion

The pans of a physical balance are in equilibrium. Air is blown under the right hand pan; then the right hand pan will

  • Move up

  • Move down

  • Move erratically

  • Remain at the same level

A sniper fires a rifle bullet into a gasoline tank making a hole 53.0 m below the surface of gasoline. The tank was sealed at 3.10 atm. The stored gasoline has a density of 660 kgm-3. The velocity with which gasoline begins to shoot out of the hole is
(a) 27.8 ms-1                                            (b) 41.0 ms-1
(c)  9.6 ms-1                                             (d) 19.7 ms-1

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An L-shaped tube with a small orifice is held in a water stream as shown in fig. The upper end of the tube is 10.6 cm above the surface of water. What will be the height of the jet of water coming from the orifice? Velocity of water stream is 2.45 m/s.
         

 

  • Zero                                         

  • 20.0 cm                   
  • 10.6 cm                                   
  • 40.0 cm

Fig. represents vertical sections of four wings moving horizontally in air. In which case the force is upwards

  •  

  •  

  •  

A tank is filled with water up to a height H. Water is allowed to come out of a hole P in one of the walls at a depth D below the surface of water. Express the horizontal distance x in terms of H and D

  • () x=D(H-D)

  • () x=D(H-D)2

  • () x=2D(H-D)

  • () x=4D(H-D)

A rectangular vessel when full of water takes 10 minutes to be emptied through an orifice in its bottom. How much time will it take to be emptied when half filled with water

  • 9 minute                       

  • 7 minute

  • 5 minute                       

  • 3 minute

A streamlined body falls through air from a height h on the surface of a liquid. If d and D(D > d) represents the densities of the material of the body and liquid respectively, then the time after which the body will be instantaneously at rest, is

  •  2hg                         

  •  2hg·Dd

  •  2hg·dD                   

  •  2hgdD-d

A large tank of cross-section area A is filled with water to a height H. A small hole of area 'a' is made at the base of the tank. It takes time T1 to decrease the height of water to Hη(η>1) ; and it takes T2 time to take out the rest of water. If T1=T2, then the value of η is

  • () 2                                   
  • () 3
  • () 4                                   
  • () 22

 As the temperature of water increases, its viscosity

  • Remains unchanged

  • Decreases

  • Increases

  • Increases or decreases depending on the external pressure

A small drop of water falls from rest through a large height h in air; the final velocity is

  •  h

  •  h

  •  (1/h)

  • Almost independent of h

0:0:1


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