What is the nature of the pressure-distance graph for the pipe shown in the figure?

Water is flowing through a horizontal tube as shown in the figure. Its diameters at two points are $0.3\,m$ and $0.1\,m$ respectively. The pressure difference between these two points is equal to $0.8\,m$ of water column. Find the rate of flow of water in the tube in $ltr/s$.

An aircraft of mass $3 \times 10^5 \ kg$ with total wing area $400 \ m^2$ is in a level flight at a speed of $540 \ km \ h^{-1}$. The density of air at its height is $1.2 \ kg \ m^{-3}$. The fractional increase in the speed of the air on the upper surface of its wings relative to the lower surface is . . . . . . $\left(g=10 \ ms^{-2}\right)$

Air of density $1.2 \, kg \, m^{-3}$ is blowing across the horizontal wings of an aeroplane in such a way that its speeds above and below the wings are $150 \, m \, s^{-1}$ and $100 \, m \, s^{-1}$,respectively. The pressure difference between the upper and lower sides of the wings is ........ $N \, m^{-2}$.

Figures $(a)$ and $(b)$ refer to the steady flow of a non-viscous liquid. Which of the two figures is incorrect? Why?

What type of fluid can be applied in Bernoulli's equation?