$A$ venturimeter has a pipe diameter of $4 \,cm$ and a throat diameter of $2 \,cm$. The velocity of water in the pipe section is $10 \,m/s$. The pressure drop between the pipe section and the throat section is (use density of water $= 1000 \,kg/m^3$):

Water is flowing through a horizontal pipe of non-uniform cross-section. In the region of the narrowest part inside the pipe,the water will have

The Pitot tube shown in the figure is used to measure fluid flow velocity in a pipe of cross-sectional area $S$. It was invented by a French engineer Henri Pitot in the early $18^{th}$ century. The volume of the gas flowing across the section of the pipe per unit time is (The difference in the liquid columns is $\Delta h$,$\rho_0$ and $\rho$ are the densities of liquid and the gas respectively):

Write the limitations of Bernoulli's theorem.

$A$ liquid is flowing in a horizontal pipe of non-uniform cross-section. Which of the following quantities may remain unchanged with respect to time?

Explain why the roof of a building flies off during a stormy wind.