Why does fluid flow faster in a narrow tube?

Water is flowing continuously from a tap having an internal diameter $8 \times 10^{-3} \ m$. The water velocity as it leaves the tap is $0.4 \ m/s$. The diameter of the water stream at a distance $2 \times 10^{-1} \ m$ below the tap is close to .......$\times 10^{-3} \ m$.

Water falls from a tap,down the streamline.

In a streamlined flow,the velocity of a fluid at a given point

Explain critical speed,white water rapids,and turbulent flow.

Select the incorrect statement regarding turbulent flow.