Select the incorrect statement regarding turbulent flow.

$A$ water spray gun is attached to a hose of cross-sectional area $30 \text{ cm}^2$. The gun comprises $10$ perforations,each of cross-sectional area $15 \text{ mm}^2$. If the water flows in the hose with a speed of $50 \text{ cm/s}$,calculate the speed at which the water flows out from each perforation. (Neglect any edge effects)

In a streamline flow,

Water enters through end $A$ with speed $v_1$ and leaves through end $B$ with speed $v_2$ of a cylindrical tube $AB$. The tube is always completely filled with water. In case $I$,the tube is horizontal; in case $II$,it is vertical with end $A$ upwards; and in case $III$,it is vertical with end $B$ upwards. We have $v_1 = v_2$ for:

Two water pipes of diameters $2 \text{ cm}$ and $4 \text{ cm}$ are connected with the main supply line. The velocity of flow of water in the pipe of $2 \text{ cm}$ diameter is

Assertion $(A):$ The stream of water flowing at high speed from a garden hose pipe tends to spread like a fountain when held vertically up but tends to narrow down when held vertically down.
Reason $(R):$ In any steady flow of an incompressible fluid,the volume flow rate of the fluid remains constant.