$A$ horizontal pipe carries water in a streamline flow. At a point along the pipe, where the cross-sectional area is $A_1$, the velocity of water is $V_1$ and the pressure is $P_1$. What is the pressure of water at another point where the cross-sectional area is $A_2$?

Assertion $(A)$: The upper surface of the wing of an aeroplane is made convex and the lower surface is made concave.
Reason $(R)$: The air currents at the top have smaller velocity and thus less pressure at the bottom than at the top.

Consider a water tank as shown in the figure. Its cross-sectional area is $0.4\, m^{2}$. The tank has an opening $B$ near the bottom whose cross-sectional area is $1\, cm^{2}$. $A$ load of $24\, kg$ is applied on the water at the top. When the height of the water level is $40\, cm$ above the bottom,the velocity of water coming out of the opening $B$ is $v\, ms^{-1}$. The value of $v$,to the nearest integer,is ......$m/s$. [Take value of $g$ to be $10\, ms^{-2}$]

$A$ horizontal pipe line carries water in a streamline flow. At a point along the tube where the cross-sectional area is $10^{-2} \ m^2$,the water velocity is $2 \ m/s$ and the pressure is $8000 \ Pa$. The pressure of water at another point where the cross-sectional area is $0.5 \times 10^{-2} \ m^2$ is ........ $Pa$.

If the velocity of flow is $4 \, m/s$,then the velocity head is ......... $m$.

Bernoulli’s theorem is a consequence of