What is Viscosity? – Learn Types and Coefficient of Viscosity Here!

3 months ago .


Studying various subjects should be your priority if you want to crack the engineering entrance exams such as VITEEE, JEE Main, SRMJEEE, and BITSAT. Therefore, we are sharing this article on Viscosity wherein our experts have explained what is viscosity in simple terms, its types and the coefficient of Viscosity. Read this article carefully to learn the concepts to crack the competitive exam.

Ever wondered about the flow of water and honey as liquids?

Let’s take a bottle of water and a bottle of Honey.


Now what we observe is that the water streams rapidly out of the bottle, however, honey takes some time. This happens because of the impact of viscosity as honey being thicker than water. Let us learn more about viscosity!

What is Viscosity?

It is characterized as the degree to which a liquid stands up to the flow beneath an applied force; a measure of tangential friction per unit area to the speed gradient beneath conditions of streamline stream. The property of a liquid due to which it restricts the relative movement between its diverse layers is called viscosity and the force between the layers restricting the relative movement is called viscous force For case fluids like water, liquor, petrol, and more stream openly and quicker than glycerin solution, honey. This viscous property is stated as viscosity, the fluid’s flow resistance.

The formula for Viscosity :

The measurement for viscosity is done in terms of a ratio of shearing stress to the velocity gradient in a fluid. In case a circle is dropped into a liquid, the consistency can be decided to utilize the formula:

viscosity - Testbook


  • ∆ρ: density difference between fluid and sphere tested
  • a: radius of the sphere
  • g: acceleration due to gravity
  • v: the velocity of the sphere (distance traveled by sphere/ time it takes to travel that distance)

Viscosity is measured in Pascal seconds. As you’ll see in this condition, on the off chance that the speed of the circle is less, the viscosity will be more. The more viscous a liquid is, the more resistance it offers to any object moving interior it. Further, gathering the information on the viscosity of a given material makes a difference for the producers to anticipate how the material carries on within the real world. For case, if the face cream does not have the proper thickness, it’ll either be too difficult to pump out from the tube or as well much of it’ll be pumped out. Moreover, knowing the thickness of material influences how the production and transportation processes are designed.

Type of Viscosity

There are two ways to measure a fluid’s viscosity as follows:

  • Dynamic Viscosity (Absolute Viscosity): estimation of the fluid’s internal resistance to flow
  • Kinematic Viscosity: alludes to the proportion of dynamic viscosity to density.

Fundamentally, dynamic viscosity gives you information on the force required to make the fluid flow at a certain rate, while kinematic viscosity tells how quick the fluid is moving when a certain force is applied.

Viscosity is calculated as the coefficient of viscosity as the constant for a fluid and depends on its nature. Viscosity coefficient of liquids will be diminished as the temperature increases, whereas it is converse within the case of gases where the coefficient of viscosity of gasses will increase with the increase in temperature. The increase in temperature for the liquid deliberate the bonds between molecules. These bonds are straightforwardly related to the consistency and at last, the coefficient is decreased.

Need to measure Viscosity? The viscosity information of the material gives a chance to foresee how a particular material will respond and react.

The formula for measuring viscosity is given as :

Viscosity= shear stress / shear rate

Coefficient of Viscosity

The force of friction between two layers of liquid of a given area and isolated by distance will have a velocity which is given by:

viscosity - Testbook

The unit is ordinarily expressed in poise or centipoise. The resulting unit is measured in centipoise which is the comparable of 1 mPa (MilliPascal second)

The major industries where Viscosity estimations are utilized are within the food industry to make strides by and large cost-effectiveness and maximizing productivity. Other than, the food industry Viscosity is additionally utilized in other businesses such as Cement, petroleum, Concrete, and Beauty care products as well.

We hope this article on Viscosity was helpful for you! You can also refer to similar such articles as Specific conductance, Vector Algebra to ace in the exam you are preparing for.


Try JEE Main Mock Test by Resonance

profile image
About the author: Samiksha Shambharkar