Water is flowing through a very narrow tube. The velocity of water below which the flow remains a streamline flow is known as

Two capillary tubes of the same length but different radii $r_1$ and $r_2$ are fitted in parallel to the bottom of a vessel. The pressure head is $P$. What should be the radius of a single tube that can replace the two tubes so that the rate of flow is the same as before?

If the pressure difference across a pipe of radius $r$ and length $l$ is $p$,then the volume of liquid flowing out per second is $V$. Find the correct expression for $V$.

For which of the following Reynolds numbers is a flow considered streamlined (laminar)?

$A$ horizontal pipeline carrying gasoline has a cross-sectional diameter of $5 \,mm$. If the viscosity and density of the gasoline are $6 \times 10^{-3} \,Poise$ and $720 \,kg/m^3$ respectively,the velocity after which the flow becomes turbulent is:

$A$ flow of liquid is streamline if the Reynolds number is