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?

In Poiseuille's method for the determination of the coefficient of viscosity,the physical quantity that requires the greatest accuracy in measurement is:

The rate of flow of water in a capillary tube of length $\ell$ and radius $r$ is $V.$ The rate of flow in another capillary tube of length $2 \ell$ and radius $2 r$ for the same pressure difference would be $....V$

The rate of flow of liquid in a tube of radius $r$ and length $l$,whose ends are maintained at a pressure difference $P$,is given by $V = \frac{\pi Q P r^4}{\eta l}$,where $\eta$ is the coefficient of viscosity. What is the value of $Q$?

The Reynolds number of a flow is the ratio of

Under a constant pressure head,the rate of flow of liquid through a capillary tube is $V$. If the length of the capillary is doubled and the diameter of the bore is halved,the rate of flow would become