Water flows through a horizontal pipe of variable cross-section at the rate of $12 \pi$ litre per minute. The velocity of the water at the point where the diameter of the pipe becomes $2 \text{ cm}$ is (in $\text{ m/s}$)

Which of the following is not a characteristic of turbulent flow?

Water is moving with a speed of $5.18 \; ms^{-1}$ through a pipe with a cross-sectional area of $4.20 \; cm^2$. The water gradually descends $9.66 \; m$ as the pipe increases in area to $7.60 \; cm^2$. The speed of flow at the lower level is ....... $ms^{-1}$.

In a streamline flow,

Two water pipes $P$ and $Q$ having diameters $2 \times 10^{-2} \ m$ and $4 \times 10^{-2} \ m$,respectively,are joined in series with the main supply line of water. The velocity of water flowing in pipe $P$ is

$A$ tube of length $L$ is shown in the figure. The radius of the cross-section at point $(1)$ is $2 \ cm$ and at point $(2)$ is $1 \ cm$. If the velocity of water entering at point $(1)$ is $2 \ m/s$,then the velocity of water leaving at point $(2)$ will be: (in $m/s$)