Correct Answer - Option 1 : Dynamic viscosity of water is nearly 50 times that of air
Concept:
Viscosity(μ):
-
It describes the internal friction of a moving fluid. Viscosity is a measure of the resistance of fluid towards being deformed when under shear stress. Hence, it is also known as shear viscosity. It is caused by the attractive forces between molecules in close contact and the friction between molecular chains.
- A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction.
- A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion.
Kinematic viscosity:
It is defined as the ratio between the dynamic or absolute viscosity and density of the fluid,
\(\nu = \frac{\mu }{\rho }\)
Explanation:
(i) Water is about 50 times more viscous than air.
(ii) Castor oil is about 1000 times more viscous than water.
(iii) Crude oil about 10 times more viscous than water.
(iv) Gasoline is about 1/3 times viscous than water.
Kinematic viscosity of air is more than that of water.
