Two different liquids flow through tubes of the same radius. If the ratio of their coefficients of viscosity is $52:49$ and the ratio of their densities is $13:1$,what is the ratio of their critical velocities?

The rate of steady volume flow of water through a capillary tube of length $l$ and radius $r$,under a pressure difference of $p$ is $V$. This tube is connected with another tube of the same length but half the radius,in series. Then,the rate of steady volume flow through them is (The pressure difference across the combination is $p$.)

In deriving Bernoulli's equation,we equated the work done on the fluid in the tube to its change in the potential and kinetic energy.
$(a)$ What is the largest average velocity of blood flow in an artery of diameter $2 \times 10^{-3} \;m$ if the flow must remain laminar?
$(b)$ Do the dissipative forces become more important as the fluid velocity increases? Discuss qualitatively.

In the case of a liquid, if the Reynolds number '$R_n$' is $1450$, then the flow of the liquid will

Water flows in a streamline manner through a capillary tube of radius $a$. The pressure difference is $P$ and the rate of flow is $Q$. If the radius is reduced to $\frac{a}{4}$ and the pressure is increased to $4P$,then the rate of flow becomes ................

In which one of the following cases will the liquid flow in a pipe be most streamlined?