Question
Figures 10.23 (a) and (b) refer to the steady flow of a (non-viscous) liquid. Which of the two figures is incorrect? Why?
Solution
From the law of continuity, we have
A1 = Area of pipe 1,
A2 = Area of pipe 2,
V1 = Speed of fluid in pipe 1, and
V2 = Speed of fluid in pipe 2.
When the area of cross-section in the middle of the venturimeter is small, the speed of the flow of liquid through this part is more.
According to Bernoulli's principle, if velocity is more, pressure is less.
Pressure is directly proportional to height.
Hence, the level of water in pipe 2 is less. Therefore, figure (a) is not possible.
