Home
Class 12
PHYSICS
Assertion:- For Reynolds number R(e)gt20...

Assertion:- For Reynolds number `R_(e)gt2000m`, the flow of fluid is turbulent.
Reason:- Inertial forces are dominant compared to the viscous forces at such high Reynolds number.

A

If both Assertion `&` Reason are True `&` the Reason is a correct explanation of the Assertion.

B

If both Assertion `&` Reason are True but Reason is not a correct explanation of the Assertion.

C

If Assertion is True but the Reason is False.

D

If both Assertion `&` Reason are False.

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • TEST PAPERS

    ALLEN |Exercise Part-1 Physics|15 Videos

  • TEST PAPERS

    ALLEN |Exercise part-2 physics|73 Videos

  • TEST PAPERS

    ALLEN |Exercise PAPER 2|60 Videos

  • TEST PAPER 4

    ALLEN |Exercise PHYSICS|45 Videos

  • UNIT & DIMENSIONS, BASIC MATHS AND VECTOR

    ALLEN |Exercise Exercise (J-A)|7 Videos

Similar Questions

Explore conceptually related problems

Which of the ratio of forces represents the Reynolds number Re ?

Assertion : For turbulent flow Reynolds number R_(e)gt2000 . Reason : For high value of Reynold number internal force is more effective than viscous force.

Deduce the formula of Reynolds number in the form of inertial force and viscous force .

What is the value of Reynold's number for turbulent flow ?

Assertion : A body can be at rest even when it is under the action of may number of external forces Reason : Because vector sum of the all external forces is zero .

What is change in value of Reynolds number when fluid flow from broad tube to narrow tube ? [Tube is horizontal]

When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. What is the viscous force on a glass sphere of radius r=1mm falling through water (eta=1xx10^(-3)Pa-s) when the sphere has speed of 3m/s?

When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. Blood vessel is 0.10 m in length and has a radius of 1.5xx10^(-2) m blood flows at rate of 10^(-7)m^(3)//s through this vessel. The pressure difference that must be maintained in this flow between the two ends of the vessel is 20 Pa what is the viscosity sufficient of blood?

ALLEN -TEST PAPERS-PAPER 3
  1. Assertion:- Any arbitrary displacement of charges inside a shell does ...

    Text Solution

    |

  2. Assertion:- Kirchhoff's voltage law indicates that field is conservati...

    Text Solution

    |

  3. Assertion:- Magnetism and superconductivity are natural enemies. Rea...

    Text Solution

    |

  4. Asseration: A metal piece and a non-metal (stone) piece are dropped fr...

    Text Solution

    |

  5. Assertion:- If earth did not have atomosphere, its average surface tem...

    Text Solution

    |

  6. Assertion:- Different colours of light have same velocity in vaccum, b...

    Text Solution

    |

  7. Assertion:- If an object placed on the optic axis of a lens is illumin...

    Text Solution

    |

  8. Assertion:- A simple microscope may have different magnification for d...

    Text Solution

    |

  9. Assertion : Newton's rings are formed in the reflected system. When th...

    Text Solution

    |

  10. Assertion:- A photocell is called an electric eye. Reason:- The elec...

    Text Solution

    |

  11. Assertion : Soft and hard X-rays differ in frequency as well as veloci...

    Text Solution

    |

  12. Assertion:In beta-decay, all the emitted electron do not have the same...

    Text Solution

    |

  13. Statement-I : To be used as amplifier, the transistor in the common em...

    Text Solution

    |

  14. Assertion:- Optical communication system is more economical than other...

    Text Solution

    |

  15. Assertion:- Two identical trains move in opposte sense in equatorial p...

    Text Solution

    |

  16. Statement-1: The size of a hydrogen increases as it rises in air. St...

    Text Solution

    |

  17. Assertion:- For Reynolds number R(e)gt2000m, the flow of fluid is turb...

    Text Solution

    |

  18. Assertion:- To drink chilled juicc, we use icc cubes of 0^(@)C. Reas...

    Text Solution

    |

  19. Assertion:- During adiabatic expansion of an ideal gas, temperature fa...

    Text Solution

    |

  20. Assertion:- Transvers waves are produced in a very long string fixed a...

    Text Solution

    |