A wire $($radius $R_1)$ being coated with an insulating material is pulled at a velocity of $V_o$ through a long

cylindrical die $($of radius $R_2)$ filled with an incompressible fluid $(,).$ Obtain the velocity profile $V_z(r)$

inside the die and the power required to pull the wire. Due to highly viscous nature of the fluid, assume

the flow to be laminar, steady and incompressible. Also, neglect the end effects and neglect the

pressure gradient in the direction of flow del$\frac{p}{d}$elz$=0.$