What is the value of Reynolds number for streamline flow?

When a liquid of density $\rho$ flows through a tube of diameter $d$ with critical velocity $V$,then the Reynolds number is (where $\eta$ is the coefficient of viscosity of the liquid).

Water is conveyed through a uniform tube of $8 \text{ cm}$ in diameter and $3140 \text{ m}$ in length at the rate of $2 \times 10^{-3} \text{ m}^3/\text{s}$. The pressure required to maintain the flow is (Viscosity of water $= 10^{-3} \text{ SI units}$):

$A$ liquid of density $10^3 \, kg/m^3$ and coefficient of viscosity $8 \times 10^{-2} \, \text{decapoise}$ is flowing in a tube of radius $2 \, cm$ with speed $2 \, m/s$. The Reynold's number is ..........

Consider an increase of $1 \%$ in each of the radius of the artery,the viscosity of blood,and the density of blood,respectively. The percentage change in the flow rate of blood in the artery is (in $\%$)

Under a pressure head,the rate of orderly volume flow of a liquid through a capillary tube is $Q$. If the length of the capillary tube is doubled and the diameter of the tube is halved,the rate of flow would become: