Viscosity

Viscosity :

1. Viscosity measures the resistant of flow of a liquid.

2. Viscosity is the force of friction between the successive layer of a flowing  liquid.

3. When a liquid flow through a tube, the central layer has the highest velocity,

    whereas the layer along the inner wall in the tube remains stationary.This

    create a velocity profile in pipe flow as shown in following diagram.

4. Viscosity of a liquid is decreases with increase in temperature.

5. Viscosity of liquid is also depending upon molecular size of liquid.

    Larger molecular size has more viscosity.

6. It is represented by the symbol η "eta"

7. Unit:

                    I.            SI Units is N s m^-2 or Pa s

                   II.            CGS Units is Poise or gm cm^-1s^-1

8. Unit conversion:  1 Pa s = 10 Poise