Home
Class 11
PHYSICS
Water coming out of the mouth of a tap a...


Water coming out of the mouth of a tap and falling vertically in stream line flwo forms a tapering column. i.e., the area of cross-section of the liquid column decreases as it moves down which of the following is the most accurate explanantion for this-

A

As the moves down, its speed increases and hence its pressure decreases. It is then compressed by the atmosphere.

B

Falling water tries to to reach a terminal velocity and hence reduced the area of cross-section to balance upward and downward force.

C

The mass of water flowing past and cross-section must remain constant. Also, water is almost incompressible. Hence the rate of volume flow must remain constant. As this is equal to velocity x area, the area decreases as velocity increases.

D

The surface tension causes the exposed surface area of the liquid to decrease continuously.

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • ELASTICITY, SURFACE TENSION AND FLUID MECHANICS

    ALLEN|Exercise Exercise 3 (Assertion & Reason)|32 Videos

  • ELASTICITY, SURFACE TENSION AND FLUID MECHANICS

    ALLEN|Exercise Exercise 3 (Comprehension based questions)|24 Videos

  • ELASTICITY, SURFACE TENSION AND FLUID MECHANICS

    ALLEN|Exercise Exercise 1 (Fluid Statics)|40 Videos

  • CENTRE OF MASS

    ALLEN|Exercise EXERCISE-V B|19 Videos

  • ERROR AND MEASUREMENT

    ALLEN|Exercise Part-2(Exercise-2)(B)|22 Videos

Similar Questions

Explore conceptually related problems

A cylindrical container of cross-section area, A is filled up with water upto height 'h' Water may exit through a tap of cross sectional area 'a' in the bottom of container. Find out (a) Velocity of water just after opening of tap. (b) The area of cross-section of water stream coming out of tape at depth h_(0) below tap in terms of 'a' just after opening of tap. (c) Time in which conainer becomes empty. (Given : ((a)/(A))^(1//2) = 0.22, h = 20 cm , h_(0) = 20 cm

Two very large open tanks A & F both contain the same liquid. A horizontal pipe BCD , having a small constriction at C , leads out of the bottom of tank A , and a vertical pipe E containing air opens into the constriction at C and dips into the liquid in tank F . Assume stremline flow and no viscosity. If the cross section area at C is one-half that at D , and if D is at distance h_(1) below the level of the liquid in A , to what height h_(2) will liquid rise in pipe E ? Express your answer in terms of h_(1) . [Neglect changes in atmosphere pressure with elevation. In the containers there is atmosphere above the water surface and D is also open to atmosphere.]

A conical section of a pipe is shown in figure through which water is flowing. Let A be the area of crosss-section, r be the radius of cross-section, P be the pressure at a point difference and v be the velocity of water. Match the column-I with column-II containing values of ratio of quantities given in Column-I

A person in a lift is holding a water jar, which has a small hole at the lower end its side. When the lift is at rest, the water jet coming out of the hole hits the floor of the lift at a distance d of 1.2 m from the person. In the following, state of the lift’s motion is given in Column I and the distance where the water jet hits the floor of the lift is given in Column II. Match the statements from list I with those in list II and select the correct answer using the code given below the lists.

A cylinderical tank having cross sectional area ^^=0.5m^(2) is filled liquids of densities rho_(1)=900kgm^(3)&rho_(2)=600kgm^(3) to a height h=60cm as shown in the figure a small hole having area a=5cm^(2) is made in right vertical wall at a height y=20cm from the bottom calculate. (i). velocity of efflux (ii). horizontal force F to keep the cylinder in static equilibrium if it is placed on a smooth horizontal plane (iii). minimum and maximum value of F to keep the cylinder at rest. The coefficient of friction between cylinder and the plane is mu=0.1 (iv). velocity of the top most layer of the liquid column and also the velocity of the boundary separating the two liquids.

If a body moves through a liquid or a gas then the fluid applies a force on the body which is called drag force. Direction of the drag force is always opposite to the motion of the body relative to the fluid. At low speeds of the body, drag frog ( F _(P)) is directly proportional to the speed. F_(D) = kv What K is a proportionally constant and it depends upon the dimension of the body moving in air at relatively high speeds, the drag force applied by air an the body is proportional to v^(2) Where this proportionally constant K can be given by K_(2) rho CA Where rho is the density of air C is another constant givig the drag property of air A is area of cross-section of the body Consider a case an object of mass m is released from a height h and it falls under gravity. As it's speed increases the drag force starts increasing on the object. Due to this at some instant, the object attains equilibrium. The speed attained by the body at this instant is called "terminal speed" of the body. Assume that the drag force applied by air on the body follows the relation F_(D) = kv ,neglect the force by buoyancy applied by air on the body then answer the following questions. What is the pattern of acceleration change of the body ?

If a body moves through a liquid or a gas then the fluid applies a force on the body which is called drag force. Direction of the drag force is always opposite to the motion of the body relative to the fluid. At low speeds of the body, drag frog ( F _(P)) is directly proportional to the speed. F_(D) = kv What K is a proportionally constant and it depends upon the dimension of the body moving in air at relatively high speeds, the drag force applied by air an the body is proportional to v^(2) Where this proportionally constant K can be given by K_(2) rho CA Where rho is the density of air C is another constant givig the drag property of air A is area of cross-section of the body Consider a case an object of mass m is released from a height h and it falls under gravity. As it's speed increases the drag force starts increasing on the object. Due to this at some instant, the object attains equilibrium. The speed attained by the body at this instant is called "terminal speed" of the body. Assume that the drag force applied by air on the body follows the relation F_(D) = kv ,neglect the force by buoyancy applied by air on the body then answer the following questions. What is the terminal speed of the object ?

A block is released on the slant face of a wedge of equal mass placed on a horizontal floor. The slant face of the wedge makes an angle of 45^(@) with the floor. Coefficient of friction between all surfaces in contact is the same. Different value/ range of coefficient of friction is given in column I and corresponding consequences in column II and III (wedge is fress to move) {:(,"Column-I",,"Column-II",,"Column-III",),((I),mu=0,(i),"Work done by friction on block and wedge is negative (on each)",(P),"Centre of mass of system (block+wedge) moves rightward and downward",),((II),mu gt 1,(ii),"Work done by friction on block is negative but on wedge it is zero",(Q),"Centre of mass of system (block+wedge) moves leftward and downward",),((III),sqrt(5)-2 lt mu lt 1,(iii),"Work done by friction on block and wedge is zero (on each)",(R ),"Centre of mass of system (block+wedge) remains at rest",),((IV),mu lt sqrt(5) - 2,(iv),"Friction between the block and wedge is static and between the wedge and ground it is kinetic in nature.",(S),"Centre of mass of system (block+wedge) moves vertically downward",):} Which of the following options is the correct representaion of the case that the block slides down the wedge and wedge slide on the floor

In a metal in the solid state, such as a copper wire, the atoms are strongly bound to one another and occupý fixed positions. Some electrons (called the conductor electrons) are free to move in the body of the metal while the other are strongly bound to their atoms. In good conductors, the number of free electrons is very large of the order of 10^(28) electrons per cubic metre in copper. The free electrons are in random motion and keep colliding with atoms. At room temperature, they move with velocities of the order of 10^5 m/s. These velocities are completely random and there is not net flow of charge in any directions. If a potential difference is maintained between the ends of the metal wire (by connecting it across a battery), an electric field is set up which accelerates the free electrons: These accelerated electrons frequently collide with the atoms of the conductor, as a result, they acquire a constant speed called the drift speed which is given by V_e = 1/enA where I = current in the conductor due to drifting electrons, e = charge of electron, n = number of free electrons per unit volume of the conductor and A = area of cross-section of the conductor. A constant potential difference is maintained between the ends of a conductor having nonuniform cross-section. Which of the following quantities will not change along the length of the conductor

In the adjacent figure a cylindrical vessel of mass M and cross - sectional area A is placed inverted on a fixed smooth piston of same cross - sectional area fixed to the ground . The space between the cylinder and priston is completely filled with liquid of density rho . There is a small office of cross - sectional area a ( a lt lt A) at the top top portion of this vessel . ( intially length of the liquid column in the vessel is H ) Speed of the liquid with which it comes out of the vessel is

ALLEN-ELASTICITY, SURFACE TENSION AND FLUID MECHANICS-Exercise 2 (One or more than one correct answer)
  1. A sealed tank containing a liquid of density rho moves with horizontal...

    Text Solution

    |

  2. The U - tube shown has a uniform cross - section. A liquid is filled i...

    Text Solution

    |

  3. Water coming out of the mouth of a tap and falling vertically in strea...

    Text Solution

    |

  4. There are two identical small holes on the opposite side of a tank co...

    Text Solution

    |

  5. A U-tube of uniform cross section is partially filled with a liquid I....

    Text Solution

    |

  6. A container of a large uniform cross sectional area A strong on horizo...

    Text Solution

    |

  7. A mercury manometer is connected as shown in the figure. The differenc...

    Text Solution

    |

  8. An open pan P filled with water of density (rhow) is placed on a verti...

    Text Solution

    |

  9. A small ball is left in a viscous liquid form very much height correct...

    Text Solution

    |

  10. A cubical block of side a and density rho slides over a fixed inclined...

    Text Solution

    |

  11. A space 2.5cm wide between two large plane surfaces is filled with oil...

    Text Solution

    |

  12. A large drop of oil whose density is less than that of water, floats ...

    Text Solution

    |

  13. If the terminal speed of a sphere of gold (of density 19.5 g//cm ^3 ) ...

    Text Solution

    |

  14. A spherical ball is dropped in a long column of viscous liquid. Which ...

    Text Solution

    |

  15. A small sphere of mass m is dropped from a aheight After it has fallen...

    Text Solution

    |

  16. The wires A and B shown in Fig. are made of the same material and have...

    Text Solution

    |

  17. When a capillary tube is dipped in a liquid, the liquid rises to a hei...

    Text Solution

    |

  18. A massless conical flask filled with a liquid is kepth on t a table in...

    Text Solution

    |

  19. The vessel shown in the figure has a two sections of areas of cross-se...

    Text Solution

    |

  20. A liquid flows through a horizontal tube. The velocities of the liquid...

    Text Solution

    |