Co-efficient of Viscosity
According to Newton’s law of viscosity, the viscous drag, between these layers is,
- Directly proportional to area (A) of the layer F ∝ A
- Directly proportional to velocity gradient (dv/dx) between the layers F ∝ (dv/dx)
Therefore, it can be written as:
F ∝ A (dv/dx)
Lets remove the proportionality sign by introducing a proportionality constant η.
F = η A (dv/dx)
Here, η is called the coefficient of viscosity.
If A = 1 m2 and dv/dx = 1 s-1 then the above expression becomes:
F = η
Thus, the coefficient of viscosity of a liquid is defined as the viscous drag or force acting per unit area of the layer having a unit velocity gradient perpendicular to the direction of the flow of the liquid.
Viscosity Co-efficient Units
Co-efficient of Viscosity is measured in various units as,
- In the CGS system, the unit of coefficient of viscosity is dynes s cm-2 or Poise
- In the SI system the unit of coefficient of viscosity N s m-2 or deca-poise
- Dimensional formula for the coefficient of viscosity is [ML-1 T-1]
What is Viscosity?
Viscosity is the measurement of the resistance of the flowing liquid. Let us learn more about viscosity with an example suppose we take two bowls, one bowl contains water and the other has honey in it, we drop the content of both bowls then we see that water flows much faster than honey which concludes that honey is more viscous than water.
Viscosity is the property of the liquids that prevents liquids from spreading. The force generated due to viscosity is called Viscous Force. Since this force is between the layers of liquids, it is also called internal friction. In this article, we will learn about viscosity its formula, measurement, and much more in detail.
Table of Content
- What is the Meaning of Viscosity?
- Viscosity Formula
- Types of Viscosity
- Measurement of Viscosity
- Applications of Viscosity
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