Introduction
Viscosity is a measure of the resistance of a fluid to a force applied to it or experienced by a
body moving through it. In other words, it indicates the ‘thickness’ (or stickyness) of a liquid.
Thus, water having low viscosity is "thin", whereas honey with high viscosity is "thick".
Cooking oils with intermittent thickness have viscosity value in between water and honey. By
heating the liquid, its thickness gets reduced or in other words its viscosity is reduced. This
indicates that viscosity is a function of temperature. Viscosity also varies with pressure.
George Gabriel Stokes, an Irish-born mathematician, spent most of his research effort on
describing fluid properties. His most significant contribution is perhaps the work on the
motion of a sphere through a viscous fluid. This work led to the development of Stokes Law,
a mathematical description of the force required to move a sphere through a quiescent,
viscous fluid at a specific velocity. This law forms the basis of the laboratory investigations
carried out in course of this work