SSC JE Civil Engineering 23-Mar-2021 Shift 1 Paper

Explanation:
Viscosity: The property that represents the internal resistance of a fluid to motion (i.e. fluidity) is called viscosity. There are two types of viscosity:
Dynamic viscosity: It is the property of a fluid which offers resistance to the movement of one layer of fluid over an adjacent layer of the fluid.
● Its SI unit is $\mathrm{N}-\mathrm{s}∕{\mathrm{m}}^2$ or $\mathrm{P}\mathrm{a}-\mathrm{s}$.
● Its C.G.S unit is Poise.
● 1 Poise $=0.1\mathrm{Pa}-\mathrm{s}=0.1\mathrm{Ns}∕{\mathrm{m}}^2$
Kinematic Viscosity: The ratio of dynamic viscosity to density appears frequently and this ratio is given by the name kinematic viscosity.
Kinematic Viscosity $\left(\mathrm{\gamma }\right)=\frac{\mathrm{Dynamic}\mathrm{viscosity}\left(\mathrm{\mu }\right)}{\mathrm{density}\left(\mathrm{\rho }\right)}$
● Its SI unit $={\mathrm{m}}^2∕\mathrm{s}$.
● Its C.G.S unit $=$ Stoke or ${\mathrm{cm}}^2∕\mathrm{s}$.
● 1 Stoke $={10}^{-4}{\mathrm{m}}^2∕\mathrm{s}$.