The flow rate of water from a tap of diameter $1.25 \text{ cm}$ is $3 \text{ litres per min}$. If the coefficient of viscosity of water is $10^{-3} \text{ Pa-s}$,the nature of the flow is:

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 $p$.)

What is critical velocity? Write its equation.

Water flows from a tap of diameter $1.5 \ cm$ with a flow rate of $7.5 \times 10^{-5} \ m^3 \ s^{-1}$. The coefficient of viscosity of water is $10^{-3} \ Pa \cdot s$. The flow is:

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?

Two capillary tubes of same length each of $50 \ cm$ but of different radii $4 \ mm$ and $2 \ mm$ are connected in series. When water flows,the pressure difference between the ends of the arrangement is $P$. Then the pressure difference between the ends of the first tube is