The venturi-meter works on:

What is a venturi meter?

The reading of a pressure gauge connected to a closed tap is $3.5 \times 10^5 \, N/m^2$. When the tap is opened,the reading of the pressure gauge falls to $3.0 \times 10^5 \, N/m^2$. The velocity of water is ........ $m/s$.

The platelets are drifting with the blood flowing in a streamline flow through a horizontal artery as shown below. The artery is contracted in region $II$. Choose the correct statement.

Air is streaming past a horizontal airplane wing such that its speed is $120 \ m/s$ over the upper surface and $90 \ m/s$ at the lower surface. If the density of air is $1.3 \ kg/m^3$ and the wing is $10 \ m$ long and has an average width of $2 \ m$,then the difference of the pressure on the two sides of the wing is ....... $Pascal$.

Water flows through a frictionless duct with a cross-section varying as shown in the figure. The pressure $p$ at points along the axis is represented by: